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B asic Fatigue Properties of JIS Steels
for Machine Structural Use
by
s*toshi NISHIJIMA
NRIM Special Report
(Technical Report)
No. 93~)2
1993
National Research Institute for Metals
2-3=12 Nakameguro , Meguroku, Tokyo, Japan
Page 2
NRIM SR-93-02
Basic Fatigue Properties of JIS Steels
for Machine Structural Use
by
Satoshi NISHIJIMA
NRIM Special Repor重
(Technical Report)
No.93-02
Ig93
National Research Institute for Metals
2-3-12Nakameguro, Meguroku, Tokyo, Japan
Page 3
Basic Fatigue Properties of JIS S毛eels for Machine Structural Use
by
Sa重oshi NISHIJIMA
NRIM Special Report (Technical Repor重)
No.93-02
Contents
Abstract_.◎◎.........,9◆....『......,.◎.ゆ....『.........◎◆............,.◆.9......會『.........9...,.....,含.....φ...9會......『.
1響Introduction..............響.『.......9.....『『........,曹............,..◎...9......『........9◆....會....會..“.............
2.Materials Sampling and Test Procedures__.__.___._.._..______._____。
29!Test Materials......9..◎◎........『..........◎.................9,◎.....曹.....『.......,9ウ..9,...9,9含ρ.....,..◎....
2.2Hea之Treatments....◎.....6...『.....,..9.『◎....『......,9.◎.........『....9◎...9.....『.............ρ.9骨.....『....
2.3Test Procedures_.『.....◎...................◎.....『.......,9.................◎.9,◎.....『.............9・......・.
2.3.1Mechanical Properties Tests____..._.___._。._____.。_..______.
2.3.2Fatigue Properties Tests………・…………...’◎9’●●”『’’’’’’”9◎...●●e’’’’’’’”『’’”…’”●◎○’’’’’”◆’,
2.4Data Analyses_.___._.__..___._...___。_..____...._...___.9_._.
2.4.1Simultaneous Regression。_.__...__._.._._._.__._。_.._..__..__.__
2.42Analysis of 5一八1 Curve_...._._..._...._.._._._.____.,。_____,・_.…・…・
3.Reference Mechanical Properties of JIS Steels_______________...,____.
3,1Variation of Properties due to Heat Treatment,.._.___.._。._._._.___._。_.._.
3.2Correlation Between Machanical Properties...。_._.._._.._._.___._._.._...__
3.2.1Monotonic Strength Parameters..__....___.._.,_._____.___,___._
3.2.2Monotonic Ductility Parameters___,_______。_一____._._..__._
4Reference Fatigue Properties of JIS Steels_.._.____,._._._._,。_..._.____...__
4.1Variation of Fatigue Strength due to}{eat Treatmenし_._.._,__。_._.._._.。_._。
42Correlation Between Fatigue Strength and Mechanical Properties..__,._____.._.
4,3Cyclic Parameters__.._._..._._。._._,__._.._.__..。_._.._...____。__
5。Factors Affecting Fatigue Properties________.___...____________.
5.1 Quench Hardenability of Steels...._.....,。。......._。..._...,.。。.....、...,。。....。.....。....._.,........
5.2Effect of Non-MetaHic Inclusions._._._._.,__..__,....___.._,.____.
6.Concluding Remarks_._.__._.__._..__。_._..__。_..._..__。_,.____.。_
Acknowledgements.。.___._.___,_._.._.__。_._._.__._.__。_。__._.,_...
References_.____.___.___._。___._._..._.___.__.__._._._
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Page 4
NRIM SR-93-02
:B紐sic F紐tigue Properties of JIS Steels fbr Machine Structural Use
by
Satoshi NlsHIJIMA*
幽
Abstract
This paper intends to provide Standard Reference Data on the basic high-cycle fatigue
strengths of current Japane.se steels and alloys which are designated in the Japanese
Industrial Standards(JIS)and most commonly used for mechanical structures. In total 162
individual heats of 15 differe.nt grades of carbon, low-alloy and stainless steels were sampled
from ordinary products of representative manufacturers in the country. Chemical composi-
tion was controlled at the materials sampling with the intent to have wide-spread values in
quench hardenability and thus to cover the range of variations to be expected in JIS
materialS. The materials were then heat treated and fatigue tested at the National Research
Institute for Metals(NRIM)according to the standardized proce.dures. Fatigue strengths
were eヤaluated under rotating bending, reversed torsion and axial loading. More than 12,000
standard smooth specimens were fatigue tested at room temperature in laboratory air and
6675-Ncurves were.statistically dete㎜ined for. different materials and loading conditions.
The analyzed data is correlated with basic enginneering properties such as hardness,
tensile and impact values of materials. Some typical dependence of the fatigue strength on
the microscopic defects and on the cyclic stress-strain properties are discussed. Primary test
data have already been published as NRIM Fatigue Data Sheets and available on request on
.exchange basis.
1吻w・ぬ 踊9那・9デ紹・な,NR刀w切9・εD伽3伽∫,∫∬∫∫・・な・H’gh一・yd昂・’∫9… Hθα∫’rθ小皿,Mθc伽∫C卿r解・偽,/>・η一紹α11’C’れdμ5加5, cyc髭。 y’ε145∫r8η9酌
*Director, Failure P亘ysics Division, NRIM.
Page 5
2 Satoshi NISK∬{MA
1。 Introduct韮。臓
The a孟m of the present paper is to provide Standard
Reference Data on the basic high-cycle fatigue
strengths of current Japanese steels and al玉oys. The
materials are all those des1gnated in the Japanese
Industrial Standards(JIS)and most commoniy used
for mechaRical.structures. The data cited here are
based on the nation-wide testing program to establish
Standard Fatigue Data on Engineering Materials in
Japan1), conducted since 1975 at the National Re-
search Institute for Metals(NRIM).
The primary data from this program have been
published periodically as NRIM Fatigue Data Sheets
(FDS), and distributed worldwide on exchange basis.
It would be better to explain brieHy about the FDS
Project, before entering further in detaiL
Background of the NRIM FDS goes back to early in
the 1960’s, where NR.IM was at the accomplishment・
of the行rst 7-year program of investment since its
foundat孟on. There was a keen demand from孟ndustries
to establ孟sh a national materials testing center which
could supP豆y h孟gh quality an(i neutral data for
Japanese materials. It was needed to help solidifying
the basis of safe and reliable use of Japanese materials
for machines and structures.
The project was widely supported from academic,
industrial and govemmental people, and NRIM en-
gaged重n the preparation to play such a role, A series
of Long-Term Creep Test童ng was at負rst initiated at
NRIM in 1966 using more than 1100 testing machines.
Another serles of Fatigue Testing was started in 1975
w重th 78(i縦erent testing facilit童es which have various
load capacities ranging from 50 kN to 1.5 MN.
Outline of the NRIM Fatigue Data Sheet Program
is describe(i elsewherel).
NRIM FDS Project includes three subthemes:
(1) Basic strength-1重fe properties of machine
structural materialS り (2)Life and crack growth properties of welded
structural steels, and
(3)Time-depende笠t strain-life properties of high-
temperature alloys
The scope of the Project implies establishment of
common basic fatigue data referable for materials
fabricators as well as for mater重als users. An Advisory
Committee was settled at NRIM to reHect opinions of
leading scientists and engineers in universities and
industries in the orientation of Project. Three Tech-
nical Advisory Subcommittees were also formed to
review in detail individual test programs and acquired
data with specialists from industries of various f玉elds.
The present paper is related to only a part of the
負rst subtheme mentioned above and deals speci倉cally
with bas孟。 high-cycle fatigue properties at room
temperature of carbon, Iow alloy and stainless steels.
Direct reference of the original FDS pubHcations2-16)
is recommended.
Topics not thoroughly treated here such as low.
cycle fatigue:17-22)or crackl growth properties will be
appeared in the subsequent publications of NRIM
Special Report. More comprehensive representation
of analyzed data in this paper can be found in NRIM
FDS Technical Reports in∫apanese23’24).
2・Materials Samp韮韮ng and Test Procedures
2.1 Test M3terials
Table l lists the materials samp韮ed and tested for
the FDS which are cited in this paper. There are 7
types of steels, such as carbon, Mn,、Cr-Mo, Ni-Cr,
Ni-Cr-Mo and stainless steels, pertaining to!5 classes
of steels and consisting of 162 heats/lots of materials.
They were successively sampled in 1975-80 from
ordinary products of representative Japanese steel
manufacturers, as hot rolled round bars, generally of
19-22mm in diameter. There were a few exception in
size for some heats of SNCM439 samples, which were
about 50 mm and hot rolled to size in NRIM. All of
them were killed ingot steels produced by LD
converter(LDC)or bas董。 electric arc(BEA)fumaces
of different capacities, as indicated in the table.
The sampling was carried out according to the
foHowing principle:
一Consider as population a who玉e of ordinary
products from representive manufacturers in the
country whose total market share covers a
malor part of the JIS steel grade in question
-Divide the range of JIS chemical composition for
the steel grade into high, med童um and low
sub-c豆asses, looking at the quench hardenabil一
Page 6
Basic Fatlgue Properties of JIS Steels for Machine Structural Use 3
Tab垂e l. Typical chemlcal composition and£ab罫ication history of the test materlals(sampled
茎n 1975-80)
Steel Typical comジos至tion Furnace(t) Ingot(t) Dia(lnm) Heat
S25Cr35Cr45Cr55C
0、25C
n.35C
n.45C
n.55C
LDCIBEA 15-nOkDCIBEA 15-110
kDC/BEA l5410kDCIBEA 15-110
2.5-6.3
Q.5-63
Q.5-6.3
Q.5-6.3
玉9-22
P9-22
P9-22
P9-22
11
P2
P1
P1
SMn438rMn443
0.38C-15Mn
n,43C-15Mn
LDCIBEA IG-80
kDCIBEA 10-86
25-60Q.5-65
19-23
P9-23
712
SCr44G G.40C4Cr LDC〆13EA 10-80 2.5-6.5 19-22 8
SCM435rCM440
035C-1Cr-0.2Mo
n.4GC-1Cr-0.2Mo
LDCIBEA 3G-80kDC/BEA 10-80
2.5-65
Q.5-6.5
19-22
P9-22
14
P5
SNC631 0.31G2.7N呈一〇.8Cr LDCIBEA 1(レ80 1.2-6.0 19-22 10
SNCM439rNCM447
0,39C4.8Ni-0.8Cr-0.2Mo
ソ47C-1.8Ni-0.8Cr-0.2Mo
BEA 10-80aEA 1〔}一30
1.2づ4
Q.5
19-22
P9-20
14
U
SUS403rUS430rUS3G4
12Cr
P7Cr
P8Cr-8Nl
BEA 10-60
aEA 30-60
aEA 1〔ト60
2.5-5.3
Q2-3.4
Q.5-34
19-22
P9-22
P9-22
11
X11
ity, and select arbitrarily one heat/lot of steel
per sub-class from each manufacturer, and
.Sample on average 12 individual heats/lots of
steels for one grade considering annual testing
capability
The sub-division of chemical composition was made
in order that the sampled materials would reHect the
range of scatter 童n population, given that they are
specified by the chemical composition with certain
allowance. More detailed comment will be given Iater
in this paper. One direct example for explanation is
the case of carbon steels, where the range of carbon
content was divided into three. This allowed to
classify the samples from a same JIS grade to those
having upper, middle and lower carbon concentra-
tions, which normally exhibit systematically different
hardness after quenching.
The grades of steels in Table l were selected as they
were known to be the most commonly used in
mechan孟cal industries, normally at heaレtreated states,
because of the importance of their fatigue perform-
ance. There are st孟11 many other special steels and
alloys which have to be considered in fatigue design-
ing. Some of them are actually teste(i in FDS
grogram, as those of case hardened steels, spring and
tool. steels and aluminum alloys. However, those data
wiU be analyzed and reported separately, as their
quality and use are very different from the present
ones,
Table 21ists the chemical cornposition of each steel
by 正adle analysis, comparing the respective JIS re-
quirement and the.resuhs for the test materials. No
particular comment is necessary, except, perhaps, for
intentiOnally三〇Wer COntent Of eXpenSive elementS
such as Mo for some steels.
2.2 He飢Treatments
Test materials were succeedingly cut into pieces of
about 200 mm ln length and heat treated at NRIM, so
as to prepare necessary speciments for each heat/lot of
steels. The heat treatment was designed according to
the following Principle:
一Normalization, quenching, and tempering are to
be carried out for carbon and Iow a賎oy steels,
whereaS a1mealing Or SOIutiOn treatrnent iS
apPlied for ferritic and austenitic stainless steels,
respectively,’as in ordinary usage of steels.
一Temperature for the treatments is selected from
typical values that are most commonly agreed
Page 7
4 Satoshi NlsHIJIMA
「fable 2. Chemical composi重lon requested in JIS(upper)and the materials tested(10wer), for ladle
analysis呈n maSS%
Steei C Si Mn 100P 100S Ni Cr Mo 100Cu
S25C0.22-0.28
O.22-G.28
G.15-0.35
f.16-032
0β0-0.60
O.37-052
≦3.0
?2.6
≦3、5 ≦0.20 ≦0、20 一
?2.8 ≦0.G7 ≦0.17 一
≦30
?10
S35C0.32-0.38
O.32-038
.G.15-035
O.20-0.30
0.6匹0.90
O.63一α81
≦3.0
?2.6
≦3.5 ≦≡0.20 ≦0.20 一
?3.0 ≦0.G7 ≦0.12 一
≦30
?12
S45C0.42-0.48
ソ42一α48
0.15-035
O.20-0.27
0.60-0.90
O.67-0.8G
≦3.0
?2.8
≦35 ≦0.20 ≦0.20 一
?2.3 ≦0.05 ≦0,12 一
≦30
ル15
S55C0.52の.58
O52-057
0.15-035
O.21-0.32
0.60-0.9G
n.67-0.84
≦3.0
?2.4
≦35 ≦0.20 ≦0.20 一?2.6 芸≦0.06 ≦0.14 一
≦30
?22
SMn4380.35-0.41
O.34-0.40
0.15-0.35
O.22の.27
1.35-1.65
P.40-159
≦3.0
?23
≦3.0 ≦0.25 …≦0.35 一
?2.0 ≦0,06 ≦0.22 一
≦30
?9
SMn4430.40-0.41
O.4(}一〇.46
0.1シ0.35
O.22-0.32
1.35-1.65
P.40-1.60
≦3.0
?2.7
≦3.0 ≦0.25 ≦0.35 一
?2.2 ≦0.10 ≦0.27 一
≦3G
?1G
SCr440 038-0.43
O.39-0.42
0.15-0.35
O.22-0.31
0.60-0.85
O.72-0.79
≦3.0
?1.9
≦3.0 ≦0.25 0.90-1.20 一
?1.3 ≦0.06 0,96-1.13 一
≦30
?1.3
SCM4350.33-0.38
O33-0.38
0.15-0.35
O.23-0.35
0.60-0.85
O.68-0.81.
≦3.0
?25
≦3.G ≦0.25 0.90-L20 0.15-030
?2.7 ≦0,12 0.96-1.09 0.15-0.19
≦30
?工8
SCM4400.38過.43
O.38-0.43
0.15-035
O.22-0.29
0.6〔レ0.85
O.69-0.85
≦3.0
?2.4
董≦3.0 ≦0.25 0.90-1.20 0,15-030
?2.3 ≦q,23 0.96-1.11 0.15-0.22
≦30
?15
SNC631 027-0.35
O.28-0.35
0.15-0.35
O.23-0.31
0.35-0.65
O.5〔レ0。65
≦3.0
?2.0
墨…3.0 2.50-3.50 0.60-1.00 一
?1.6 2.62-2.84 0.72~0.94 一
≦3G
?13
SNCM4390.36-0.43
O37-0.43
0.15-0.35
O.21-0.32
0.60-0.90
O.66-0.79
≦3.0
?2.3
≦3.G L 6{}一2.00 0,60-1.00 0,15-0,30
?2.4 1.63-1,92 0.69-0.92 0.16-0.26
≦3G
?13
SNCM4470.44尋.50
O.44-G.48
0.15-0.35
f.18-0.29
0.60-0.90
O.69-0.82
≦3.0
?15
≦3.G 1.60-2.00 0,60-1.00 0.15-0.30
?L7 1.66-1.80 0.73-0.81 0.工7-0.21.
≦30
?11
SUS403 ≦G.15
O.09-G.15
≦050
f.19-050
;≦1,00
O.3レ0.85
墨4.0
?2.9
≦3.0 ≦0.60 11.5-13.0 一
n2.2 0.08-0.29 11.7-12.8 0.02-0.!5
SUS430 ≦0.12
O.G6-0.10
≦0.75
f.30-0.59
≦1.00
O39-0.69
≦4.0
?3.9
≦3.0 - 16。0-18.0 一
?!.6 0.20-0.35 16。1-17.6 0.01-0.09
SUS304 ≦0.08
O.05-0.08
≦1.00
O.33-0.83
≦2.00
f.69-1.78
≦45
?3b
≦3.0 8.00-11.5 18。0-20.0 一
?2.8 8.3-10.28 18.2-19,6 0.07-0.32
for respecti▽e types of steels. Tempering is to be
performed a山igher, middle and lower tempera-
tures of the range rnos重popularly used for the
steel grade.
一All the treatments are conducted at NRIM using
salt baths, with a batch consisting of 24 pieces of
cut materials, of arbitrarily chosen 3 heats and
with 8 pieces per heat.
一 Statistical care is to be taken at every steps of
work not to introduce unexpected bias in the
results
Table 3 gives the condition of heat treatment
applied to the test materials. As the result, typical Iow
carbon steel S25C was only normalized, ferritic
Page 8
Basic Fatigue PτQpertles of JIS Steels for Machine Structural Use 5
Tab且e 3. Kea毛tごeatme慣 temperatures ln 。C wlth alr cQoling (AC), water
quenching(WQ), oil quenchi臓g(OQ)or water cooling(WC)
Steel Normalizing Quench呈ng Tempering
30min hold 30min hold 60min hold
S25C 885ACS35C 865AC 865WQ 550WC 600WC 650WCS45C 845AC 845WQ 550WC 6GO WC 65GWCS55C 825AC 825WQ 550WC 600WC 650WCSMn438 870AC 8450Q 550WC 60GWC 650WCSMn443 870AC 8450Q 550WC 60GWC 650WCSCr440 870AC 8550Q 550WC 600WC 650WCSCM435 870AC 8550Q 550WC 600WC 650WCSCM440 870AC 8550Q 550WC 600WC 650WCSNC631 900AC 8500Q 550WC 6GO WC 65GWCSNCM439 870AC 8450Q 58GWC 630WC 68GWCSNCM447 87GAC 8450Q 580WC 630WC 680WCSUS403 9750Q 700WC 75GWCSUS430 815 AC (Annea垂ed)
SUS304 1G80 WC(Solution treated)
stainless steel SUS430 was annealed, and austenitic
stainless steel SUS304 was solution treated, as in
general usage of those materials. The other medium
to high carbon steels and low alloy steels were
normalized and quench-tempered, with martensitic
stainless steel SUS403, as well.
Traditional materials control tests were conducted
at NRIM according to the respective JIS testing
methods:tests for non-metallic inclusions, hardness
after quench, austenitic/ferritic grain size number,
microscopic structure after heat treatments, etc.
Steels S35C, S45C, SMn438 and SMn443 were not
fully transformed into martensite deep inside the
materials, even after rapid water quenching, and
presented partly ferritic or bainitic structures. The
other quenched low alloy steels showed ordinary fine
tempered-martensitic structures. No abnormality was
found for 3 grades of stainless steels.
Austenitic grain size number was around 8 to 10 for
all materials, except for SUS304 which revealed 4 to
5.S25C and SUS430 presented ferritic grain size
number of 7 to g and 8 to 10, respectively. All
materials more or less exhibited longitudinal負brous
structures along the rolling direction.
There microscopic aspects were taken in considera-
tion in the analysis, but will not be discussed here
except for necessary cases.
2.3 Test Pmcedures
2.3.1Mechanic段l Properties Tests
Ordinary tensile, impact, and hardness properties
were determined at NRIM according to JIS methods
for every materials conditios, in order to obtain basic
mechanical characteristics.
The specimen for tensi豆e test was standard cylin-
drical one having 8 mm in diameter and 40 mm in gage
length. Charpy test specimen was ordinary 10 mm×
10mm rectangular bar having 2 mm deep U-or
V-notches with root radius of!.000r O.25 mm,
respectively. Vickers hardness was measured at 196 N
on Charpy specimens before the test. Figure l gives
dimensions of the specimens.
All the tests were replicated for 3 specimens per test
condition.
2.3.2 Fatigue Proper重ies Tests
High-cycle fatigue tests were carried out under load
contro玉for the life range higher than 5×104 cycles.
Tests were conducted by determining∫一/>curve using
18specimens on average for each testing condition.
This number of specimens was empiricaUy chosen,
assuming that at least 2 tests are needed at each of 3 to
5stress levels to determine‘slope’part or員nite豆ife
region of 5-1>curve, and around 3 more tests at least
at each of 3 more levels to evaluate fatigue limit in
‘horizonta1’parし
All tests were conducted according to the respective
Page 9
6 Satoshi NISH獄MA
140
(a)
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80
遭55
怨
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、
M18x2.5
200
50
謹20
P
(a)蓉 2
岱
(b)
55
27.5 275
の
窯
\
i2
N
RO.25
iNi
45。
150
50
㊨
U-notched V-notched
F星9.1 Specimens for(a)tensile test an(圭(b)Charpy
imI)act test.
(b)
讐
88
◎○
ら$
JISIISO, at room temperature in laboratory air, with
smooth round bar specimens of different shapes
depending on the testing machines. Specimens surface
was carefully machined to minimize the effect of
machining and且nished by Iongitudinal polishing with
600grade water p1・oof silicone carbide paper. Testing
machines were periodically calibrated and allocated
with statistical care so as to eliminate unexpected bias
in the resu豆ts.
Various testing machines in the following are used,
with specimens of a common test section having
diarneterφ, at indicated frequencies avoiding heating-
up of specimens during tests:
一Rotat孟ng bending withφ8mm specimens:27 sets
of 4-point bending type machines at 50 Hz
having capacity of 1000 N・m, and also 12 sets of
cantilever bending type atレ10 Hz and 50 N・m
-Torsional loading withφ8mm specimens:11 sets
of mechanical resonance type at 33 Hz and 50
N・m
-Axial loading withφ6mm specimens:2sets of
elect「o「nagnetic resonance type at 120-1601{z
and 50 kN, and also 2 sets of servohydraulic type
at 5-20 Hz and 50 kN
(c)
35
})ll
餓
1)ll
M1.8xl
F藍9・2 Specirnens for fatigue test under(a)ro宅ating bendi礁9,
(b) reversed torsion and (c) axia韮loading.
Figure 2 gives dimensions of the specimens. Rotat-
ing bending fatigue tests were conducted for all the
materials conditions, but the orther tests were subject
to typical conditions because of test capability restric-
tions:torsional fatigue only for materials of medium
compositions, and axial fatigue for medium materials
wi.th medium heat treatments.
2.4 D滋aAnalyses
Statistical analyses were conducted for the acquired
data from various point of views. Some were to伽d
useful correlations between different property values,
some were to check occasional anomaries in the data,
and some were to extract condensed property para-
meters from distributed data.
Ordinary statistical computations are not described
here, but two original methods employed in this work
will need to be explained.
2・4・1 Simu糞taneous Regression
In ordinary linear regress童Qn problem where a
model
y-αλ:十わ (1)
Page 10
Basic Fatigue Propertles of JIS Steels for Machine Structural Use 7
is considered,κis、independent variable which can be
set exactly at desired values in the measurement of y,
Asimple example for explanation would be the
weight of books for y and the number of pages foα. y
is cal正ed as dependent variabie and subject to statistic-
al variation. The coefncientαcan be estimated from
measured data, by minimizing the sum of squared
residuals in yう.or.l onκ一y co-ordinates the sum of
squared distances in the ordinate direction between
individual data and the regressed curve.
SupPose nQw that the we孟ght y is plotted against the
thickness of bookl asκ. The latter should contain
stat量stica豆error, because it is also dependent on the
number of pages. In this case, the error is to be
considered both for y andκsimultaneously, as they
are equally dependent on the measurement condition.
In such a circumstance, the sum of squared dis-
tances in the perpendicular direction from the curve
to each data point is to be minimized. This gives the
slope of regressed curve, as in the principle compo-
nent analysis, as25)
α=V (∬y/∬x) (2)
where∫5y and 33X are the variances of y andκ,
respectively.わis estimated as in the ordinary way,
わ=(Σy一αΣ]κ)/η (3)
whereηis the number of data points.
The method is widely used in analyzing the correla-
tion between different properties of materials in this
pape「・
2.4.2 Analysis of 5・1V Curve
Statistical plann孟ng of fatigue tests and ana正ysis of
acquired data is in general not an easy problem.
One of the particularities of fatigue data is that it
substantially involves tmncated data. Fatigue test can
be often suspended at prescribed number of cycles,
when it is conducted at low stress levels. The data is
called“truncated”in this case and gives information
only that the fatigue life is longer than that number of
cycles. A rough sketch of the analysis method is given
here, as the detail was reported already25・26).
Probit analysis method is known to be applied to
those suspended data. It is in fact poss圭ble to know
relationship of the failure probability,ρ, to the stress
level, 3, by conducting replicated fatigue tests at
several Ievels of∫. Experimental data forρ is
calculated as the percentage of failed specimens at
each level, observed before the predetermined num-
ber of cycles for test truncation.
In the Probit method, the sets ofρ一5 data can be
plotted on the normal probabiiity paper to be飴ed to
astraight line, assuming a normal distribution for the
distribution of fatigue strength. The mean of fatigue
strength is then known as the intersection of the fitted
line andρ窺50%, and the standard deviation as the
inverse of the siope of Iine. At Ieast two or more sets
of ρ一5 0bservations are needed to eva豆uate the
distribution, as the process requ孟res determination of
a straight line on the probability paper.
However, only one set of data can be enough, if the
problem is to determine a stra孟ght line at a given
slope. This is the case that p-5 data is analy2:ed under
given standard deviation25). This method is in fact
very advantageous for the analys量s of ordinary small
sample 5-1>data, as those data rarely include enough
suspended data pertaining to several stress levels. The
question is how to find the standard deviation of
fatigue strength.
The standard devlation can be approximated by the
root mean square of residuals from the薮tted mean
curve to the‘slope’part of 3-N data. The simul-
taneous regression method was used to盒t the slope
part data, considering that the source of scatter is
twofold, both in life and strength. The former is
intrinsic to the fatigue process itself, and the正atter is
due to the assumption that a same stress cannot cause
the same damage in different specimens because of
material.s strength variations. An experimental evi-
dence supPorts thお hypothesis25).
In the present paper, a hockey stick type bi-1inear
3-1>curve is fitted to the data on互dg-log coordinates in
order to determine the parameters characterizing the
curve. They are:slope、4, knee point 2Vw in cycles,
fatigue limitσw in N/mm2. The equation of 5一ノ>curve
is then,
y=/1{1κ一五)1一(κ一D)}/2+E (4)
where y=logσ,κ瓢log/Vf, D=109/>㌧. and左=lo9σ雨.
The 5一ノ>curve thus determined represents average
high cycle fatigue property of the materials at 50%of
fracture probability. Coef貸cient of variation CV in
fatigue strength can be calcuiated from the sum of
Page 11
8 Satoshi NlsHIJIMA
squared residuals from the curve. Example will be
shown星ater in chapter 4.
It is note(i that the above-explained statistica豆
methOd iS in prinCiple the Same aS the One inVOIVed in
the standard method of statistical fatigue testing27)by
3apan Society of Mechanical Englneers(JSME).
Howeveτthe ac窒ual analysis was not dependent on the
standard, since the majority of the work was carried
out before the establishment of JSME standard.
3.Re艶rence Mechanical Properties of JIS Steels
In this chapter wil玉be examined how the basic
mechanical properties vary according to the grade of
steels and following the heat treatments, and how
they can be correlated to each other.
3.1 Var董ation of Pmperties Due to Heat Treatment
Figure 3 shows tensile strength data of vafious
quench-tempered steels plotted against tempe血g
temperature. All the data of 3 tests per materials
condition are plotted here. The band in each diagram
gives 95%con倉dence intervals of estimates obtained
by ordinary regression analysis, assuming linear reia-
tions between strength and temperature for these
temperature ranges, and at the same time, between
scatter of strength and temperature, as welL
It is noted that the tensile strength is systematically
decreas童ng, together with its scatter, when the
tempering is conducted at higher temperatures. Simi-
lar tendency is observed for £he other strength
parameters, such as upper yield strength and/or O.2%
proof stress, true fracture strength and Vickers
hardneSS24).
The data in Fig.1is suggesting that the same level
of strength could be attained with different grades of
steels by selecting apPropriate tempering tempera-
tures, while the scatter within the steel grade would
not be the same.
Figure 4 dem6nstrates reverse dependence on
tempering temperature for elongation, where the
value is increasing with increasing temperaure!rhe
tendency is the same for the other ductility para-
meters, such as uniform elongation and reduction in
area. Charpy impact values at room temperature vary
in the same way, proving that they are oftern referred
as an index of ductility in practice. The work
hardening exponent behaves similarly to ductility
parameters, as it has been said to represent the
elongation at maximum load on true stress-strain
diagram.
The systematic change in strength and ductility
ぐ置
章
乙
8£
留
2あ
2’笏
o
1100
1000
900
800
700
600 500
1300
S35C
\iこ1\
層、
600
S45C
彗\
\
十
P、
1200
1100
1000
900
800 500
700500 600
S55C
\ 隔_ 、、
_ 、
十
SMn438
慈.
SMn443 SUS403
峯\
\ 噛 、
\・ \気1ミ
700500 6GO 700500 600 700500 600 700600 700 800
SCr440
\
_
600
キ
蜜
‡ミ
SCM435
\も
\
700500
Fig.3
CM440 SNC631
\
薫亀\ , 、
、\ し
、
、季\ 、
亀
、
S憩CM439
、
\●
\
\
し
、
SNCM447
璽
キ\.
\
600 700500 600 700500 60G 700530 630
Tempering Tem2erature T(。C)
Relation of te臓slle strengthσB and temperlng temperature 7「.
、
\
\
730530 630 730
Page 12
(
ゆ
.9
萄bD口
2
18
16
14
12
10
8
6 500
14
12
10
8
Basic Fatigue Properties of JIS Steels for Mac勧ine S之ructural Use 9
S35C
十9
//
600
S45C
妻/鍵
0‡
6
4500
700500 600
S55C SMn438 SMn443 SUS403
’
9
/, ’
P’
o θ^.
^ ρ
ρ
’
9
,
ノ
700500 600 7GO 500 600 700500 600 7006GO 700 800
SCr440 SCM435
/.
^σ
// θ
ρ
600
SCM440
/
9
ρ
/
十
’
/
’
SNC631 SNCM439 SNCM447
,●
//
φ@ ,@ρ
履 十.!富
/
・/9
汐 7
700500 600 700500 6GO 700 500 600 700530 630
Temρering Tem勲era田re T(℃)
Kg.4 Relation of elongatlonδand temρering temperature T.
350
730530 630 730
parameters with tempering is considered to be related
to the quench hardenabil重ty of steels. In fact, addition
of the alloying elements such as Mn, Cr and Ni
increase the hardness after quench with varying
degrees with their amount. In other words, it in-
creases the strength parameters and decreases the
ductility parameters. This hardening effeα is
weakened by tempering with greater extent when the
tempering is performed at higher temperatures, re-
sulting the decrease in scatter between steels.
It can also be seen in Fig.4that the change in
scatter of elongation associated with tempering
temperature is not unique for different steels. It
decreases as temperature increases for general cases,
but increases obviously for steels SCM435 and
SCM440, in contrast to the others.}iowever, the
reduction in area for the same steels revealed decreas-
ing scatters w貢h increasing temperature, as in general
steelS24).
The increasing scatter with enhanced tempering,
observed for the elongation of SCM steels, can not be
explained by the general trend of quench-tempering.
Similar abnormal trend was found also for true
fracture strength and Charpy V-notch impact value
for the same SCM steels. It will need further study to
》30G
圏
盤250謹
選
竈20G
養
>150
100
ム885℃nQrmalizedo550℃tempercd after quencho6000C tempered after quench◇瓢蓋empe「ed磨te「・目
B・・日 。韻
B。 o
o
日 日
日日8
8 0
00$
0.20 0.25 0.30 0.35 α40 0.45 0.50 0.55 0.60
Carbon Content C(mass%)
Fig.5 Typical variation ln Vlckers hardness Hy for carbon
steels in function of carbon content C and heat
treatments.
understand the cause of this trend, which can
seemingly be related to the instability at fracture for
that type of steels.
Figure 5 shows typica豆dependence of Vickers
hardness, Hγ, on their carbon content, C%, for
carbon steels. The 95%confidence bands in the figure
were traced after regression analysis, assuming a
mathematical relation for quench-tempered steels,
豆og(Hγ)==αIo9(C)一わIo9(273十7)+c (5)
where T is tempering temperature andα,わand c are
constants.
Page 13
10 Satoshi NIS田」まMA
It would be self-understanding that the hardness is
increasing with carbon contents for quench-tempered
steels, as£he quench hardenability is directly re豆ated
to the carbon contents. Hardness is also increasing for
normalized steels, as the amount of pearlitic structure
is increasing with carbon contents. The figure allows
to estimate the hardness range of other classes of
steels no乞tested in the program, such as S43C or S48C
steels, having O.40-0.46C and O.45-0.51C, respec-
tively。
Quite similar results were obtained for the other
strength parameters as yield and tensile strengths and
contrary results for the ductility parameters as elonga-
tion and reduction in area24).
Adetailed list of statistically analyzed results w韮l be
found in Appendix.
3.2 Corre藍田ion君etween Mechanlc翫l Propertles
It is empirically known that good correlation is
o負en found between different mechanical properties
of metallic materials, as for example the one between
tensile strength and hardness, In some circumstances,
the mechanical property is said to be estimated
satisfactorily in an engineering sense from basic
materials para.meters such as hardness. Actual situa-
tion is shown in.the following.
3.2.1Monoto盤ic Strength P劉rameters
Mechanical properties tested by a single application
of Ioad are oftern called‘monotonic’properties to
distinguish them from‘cyclic’ones obtained under
repeated loading characterizing fatigue.
There are 5 monotonic strength parameters de-
duced from the test, namely, upper yield strength,
0,2% proof stress, tensile strength, true fracture
strength, an(i Vickers hardness. Statistical analyses
were carried out to find significant correlations be-
tween them, and some typical ones wiU be displayed
in the following figures.
In each figure the 95%confidence bands are shown
for of estimates obtained by the simultaneous regres-
sion method explained above. The analysis was
conducted on lo9-10g coordinates by changing the
materials grouping and the results presenting max-
imum coverage was shown in the figure.
Figure 6 shows typical dependence of O.2%proof
stress on tensile strength. It is interesting t()note that
ρE…
讐
乞
禦
沼
巴
あ
ち
2窪
1200
1000
800
600
400
200
÷ S25C・} S35C. S45C, S55C
SMn438, SMn443・{ SCr440. SCM435. SCM440 SNC631,SNCM439, SNCM447△ SUS304▽ SUS430 0
◇ SUS403
口 ε
o
o
400 500 600 700 800 .900 10{〕{) 1100 1200 1300
Tensiie StrengthσB(N/mm2)
F量g。6 Re垂ation of O.2%proof stress%,2 to tensile strength
σB・
ρ長
Eを
ざ
転ぎ
巴
あ
配
ヨ
謁
虚
豊
ζ
2500
2000
1500
1000
500
▽
△込
念ム
◇
口
+ S25Cロ}S35C. S45C, S55C
lSM目438、 SMn443
o
SCr440. SCM435, SCM440・}、。C631.S。CM439、 S。CM、4
△ SUS304▽ SUS430◇SUS4〔〕3
4〔X〕 5〔X〕 600 700 800 900 1{}{X} 1100 1200 130G
つ Tensile Streng芝hσB(N/mmつ
F童g。7 Relation of true fracture strengthσr to tenslle strength
σB・
many quench-tempered carbon and low alloy steels
behave quite similarly, together with 13Cr stainless
steels SUS403, as they all have high-temperature
tempered martensitic(HTTM)structures. Another
grouping is poss孟ble for normalized low carbon stee}s
S25C having ferrite-pearlite (FIP) structures and
annealed 17Cr stainless steels SUS430 having ferritic
structures, Fig.6, while they are tentatively incorpo-
rated in the HTTM group. The third group is solution
treated 18Cr-8Ni stainless steels SUS304 with austeni-
tlc structures.
Figures 7 and 8 reveal similar dependence of other
monotonic properties on tensile strength/rrue frac-
ture strength in Fig.7is considered to be the Iimiting
property of the matrix at severely deformed state,
whereas Vickers hardness in Fig.8 refiects the
resistance of matrix at local deformation. HTTM
Page 14
Baslc Fatigue Pro麹erties of JIS Steels for Machlne Structural Use 11
400
350
300
250
200
150
100
+ S25C司 S35C, S45C, S55C
SMn438, SMn443
・{ SCr44{》. SCM435. SCM44〔}
SNC631.SNCM439、 SNCM447ム SUS3〔,4
V SUS430◇ SUS4〔〕3 0
び1 口
o
40{7 500 600 700 800 900 100G HOO 正200 i300
つ Tensile S!rcngthσ白(Nlmmつ
Ei霧.8 Relation of Vickers hardness Hγto tensile streng由
σB・
8〔〕
蕊60ざ
屋
憲 40ぎ
2国
2G
0
◇
う
司
・1
含
◇
S25CS35C. S45C, SS5C
SMn438. SMn443
SCr44{〕, SCM435.SCM440
SNC631.SNCM439.・SNCM447層目S304SUS431⊃SUS403
o
4{}0 500 6{,0 700 8(}0 900 1{}0{} 1ioθ 玉2e{} 置300
Tcnsile StrcngthσB(N/mmz)
Fig.10 Relation of elonga£lonδto tensile strengthσ8,
ρ盲
籠
へz
禦
同
訓
あ
ち含
畠
1200
正〔〕{x〕
800
6〔x}
40{〕
20〔〕
+ S25C・{ S35C, S45C, S55C
SMn438, SMn443・{ SCr440, SCM435. SCM440 SNC631,SNCM439, SNCM447△ SUS304ワ SUS430◇ SUS403
口浮
ロ ロ
100 150 200 250 3〔}0 350 400
Vickers Hardness Hγ
Fig・9 RLelatio翻of G.2%proof stressσヒ〕.2 to Vまckers hardness
∫ノγ.
90
80
70
60
50
40
サ
考
腐
ASUS3{}4
VSUS43(⊃
◇SUS403
+S25C S35C, S45C. S55C
SMn438, SMn443・l SCr440, SCM435, SCM440 SNC631,SNCM439. SNCM447
40{〕 5GO 6◎0 700 800 900 1000 1100 1200 1300
Tensiie Strengthσ拾(Nlm組2)
F韮9。1茎 R.elation of reduction in areaφto tensi垂e strengthσB.
materials behave always in one group, but the
grouping of F/P materials is not unique. The behavior
of FIP materials seems to be dependent on the amount
of plastic deformation which is brought about when
the property in question is measured.
In Fig.9where proof stress and Vickers hardness
are correlated, the group FIP is closer to the other
groups, the reason being assumed that the two
properties are determined both at relatively small
Plastic strains.
For austenitic stainless steels the behavior is be-
lieved to be more deformation sensit玉ve than FIP
steels. They are character童zed with the lowest proof
stresses and the highest true fracture strengths for
materials of same strength levels, as can be seen in
Figs.7 and 8, implying their pronounced work
hardenability.
The ratio of tensile strength in N/mm2 to Vickers
hardness,σ珍/Hy, is determined for the present data,
as
一Ferritic stainless steels, SUS430:
一HTTM carbon and low alloy steels:
一Low carbon F/P steels, S25C:
一Austenitic stain互ess steels,SUS304:
3.2.2 Monotonlc Ductility Parameters
2.91
3.12
3,44
4.00
Flgures iO to 12 show typical monotonic ducti三ity
parameters obtained from tensile test. They are all
decreasing with increasing strength, but in various
WayS frOm CaSe tO CaSe.
The relationship between elongation and tensile
strengt葦}, Fig.10, seems to be unique for different
microstructural groups of steels, except for austenitic
steels. However, the grouping becomes far complex
when reduction in area is plotted against tensile
Page 15
12 Satoshi NISHIJIMA
0.35
0.31}二
二・・25
ぎ〔〕.20
’≡
名
濤0.15
着。.10
汐
0.05
0
葎十
▽
¥
△SUS3〔.,4
▽SUS43(.}
◇ SUS403
慶△
9△
+S25C。lS35C・S45C・S55CiSMn438. SMn443
・{
SCr440, SCM435, SCM440
SNC631.SNCM439. SNCM447
◇
8
巳 邑
・%
o
o
4{}G 5(,0 6{〕0 7〔}0 80G 900 1〔X}0 正10G l200 1300
Tensile Stre駿gthσb(N/!nmユ)
Fig議2 Re互ation of work hardening exponentηto tensile strength (乃3.
ヒ
琶
雲
曾
曽’旧
名お
ゼ
≧
030
0.25
0.20
0..裏5
0.10
0.05
緊
翰十
蒔▽
種v
▽聾
▽
+ S25C S35C, S45C、 S55C
SMn438, SMn443
十
口
口
・{
SCr44〔1, SCM435. SCM440・l
SNC631,SNCM439、 SNCM【447△ SUS3{}4
v SUS430◇ SUS403
◇雛
◇
o
ら
0 0.3 0.4 05 0.6 0.7 0.8 0.9 i
Yie!d Ratioσb2/σ琶
Fig.14 Relation of work hardening exponentηto yie1(至ratio
σb.2/σ白、
80
70
ハ§609く)=
¢ 50.9
驚
ぎ402国 30
∈≡
δ
踏 20
10
00
+ S25C・} S35C, S45C. S55C
SMn438. SMn443・} SCr440, SCM435, SCM440 SNC631.SNCM439, SNCM447△ SUS304▽ SUS430◇ SUS403
:
緒・
ム
ム
10 20 30 40 50 60 70 80 90
Eiongationδ(%)
Relation of uI}至forrn elongation δu to elongat三〇賑 δ.
6へ 350慈
ミ
。 嵩300
雪
葺250昆
葺2〔玲
詮
莞150Qも
ち 100早
⊃
50
2・
・簿
◇
◇◇
Q ◇ o oo
8。。o
。 禽 留&
o日
。
ロSMn438, SMn443 SCr440. SCM435,SCM440・{
SNC631,SNCM439、 SNCM447 SUS4〔〕3
q
σ
o
o
oOo(6
o
F藍9.13
o
6{X} 7{Xl 8〔}0 9〔}〔} 1{X}{} 1!〔X} 1200 13【}O
つ Tじnsiie Sτrcngthσ1玉(N/mmつ
Fig」5 Relation of U-notch Charpy lmpact value Eσto tens呈韮e strcngth (η3.
strength, Fig.11. Even within HTTM structures,
carbon and low-alloy steels do not behave in the same
way・
It is considered that the correlation between prop-
erties is in principle different for different microstruc-
tures for those highly deformed fanges. On the
contrary, the work hardening exponent which was
deduced for p藍astic deformations ranges of 2-5%for
HTTM stee豆s and 4-10% for the others, Fig.!2,
shows no clear discrepancy within HTTM steels.
Figure 13 shows the relation of uniform elongation
between total elongation. It suggests different de-
formation stabilities of microstructures against neck-
ing. Austenitic steels show the highest stability here,
as the ratio of uniform to conventional elongations is
near O.9,}{町M carbon and low alloy steels the
lowest with the ratio less than O.5, and ferritic steels
between the two.
Figure 14 correlates work hardening exponent of
different groups of steels with yield ratio. This can be
understood that the relative stress increm.ent from
yield to ultimate tensile strengths, (0拾一〇b.2)/σ盆, is
more directly related to the work hardening. It is
observed only in this負gure that martensitic stainless
steels SUS403 show different response from the other
HTTM steels.
Figure 15 represents relation of Charpy impact
values to tensile strength for HTTM low alloy steels.
U-notched specimens are generally used in JIS for low
alloy steels, whi.le for carbon steels are specified only
with V-notched specimens. The results for HTTM
carbon steels are not represented here but quite
similar to those in Fig.15.
There is no substantial difference between the
Page 16
Basic Fatigue Properties of JIS Steels for Machine Stmctural Use 13
ρ300塁
言250
葦…
昼15・
ξ…
150
0
ロSMn438, SMn443 SCr440, SCM435. SCM440・{
SNC63i.SNCM439, SNCM447
o
む。 。亀。。
o
0 50 100 150 200 250 3GO
U-notch Charpy Impact.Va沁e E、、(」/cm2)
Relation of V-notch Charpy lmpact value Eγto that
of U-notch Eひ
800
7GO
ゆ∈
遅600
とご沼
巴
あ500
F藍9」6
400
SCM440600。C芝empcred
Rotating Bendlng
十
十
十++÷ @+調…5慮
÷ 柵 十
十十 十 十 十十
十十トシ2516
6工6
十 胴レ 2
80
7G
60
50
350
104 105 106 107 108 Number of Cycles留
F董g。18 Typical&/V diagram showlng rotating bendingξatigue
propertles of SCM440 steel tempered at 60G。C a£ter
quench. Numbers in the農gure in6icate those of
runout speciments at the test stress leveL
ぐ已
£
o貯
雪
鷲〉
ぢ
引
回
a島
嘉Qもち
阜
300
250
200
150
1oo
OSMn438. SMn443・} SCr440. SCM435. SCM44〔}
SNC631,SNCM439、 SNCM447◇ SUS403
日。δ口
o
o
・・。 ・。魯。
Φ 80
oo
・象
・鷺◇
◇
o
5%5 50 55 60 65 70 75 80 Reduction in Areaφ(%)
F量g.17 Relation of’U-notch Charpy impact value石σto
reduction j膝 area φ.
results with U-notched specimens and V-notched,
excepting that the former give 1.2 times豆arger values,
as can be seen in Fig. 16.
Figure 17 shows that the Charpy impact value at
room temperature can be directly correlated to the
reduction in area, independent to the classes of
HTTM steels. This explains why the impact value is
often referred to evaluate monotonic ductility of the
engineering materiaiS.
4. Ref¢rence Fat韮gue Properties of JIS Stee韮s
Figure!8 shows a頁example of 5-2>data obtained
for SCM440 steels tempered at 6000C after normaliz-
ing and quenching. Curves represent, from Iower to
upper, responses at 10, 50 and 90% of failure
probabilities, respectively, obta量ned after the analysis
by the bi-linear curve fitting explained above. There
are in total 303 data points pertaining to 15 different
heats, which are collectively analyzed in this case.
Analysis was of course made for each set of
individua豆heat, but the results are not given here.
There have been found some interestlng statisticaI
trends,ミuch as the slope of 5一ハ1 curve increases and
the k:nee point decreases, with increasing materials
strength, Details can be found in a separate report25),
and are not described here。
Afull list of analyzed data will be given in
Appendix for information. It gives 5-!>curve para-
meters for each grade of steels under different董oad
cond量tions.5-1>curves are analysed for the plot on
ordinary stress scale and for normalized stress scales
both by tensile strength and Vickers hardness as we1L
4.1 Variation of F劉tigue Strength due to He滋Treat-
ment
Figure 19 shows the variation of fatigue properties
under rotating bending determined at each materials
conditions in this work. The results for S25C and
SUS304 are not given here and can be found in
Appendix. As far as the fatigue limit is concerned, it
revealed very similar dependence on tempering
temperature to the monotonic strength parameters
shown earlier:it was decreasing w童th its scatter with
lncreaslng temperature・
The dependence on tempering temperature was
generally the same for fatigue strengths under torsion-
al and axial loading. They were also found to be
correlated to the carbon content in the same way as
Page 17
14 Satosh呈NISHIJIMA
ρ蓬
笙
乞
ζbタ
.蟹
岳
’コ
雲
.聾
琶
匹bD
,頸
で
oq⇒
の.頸
罵
ぢ
550
50G
450
400
350
十
S35C
30禦0〔〕
650
600
}
S45C‡
鋒/
700500
津 S55C
季\
\藁
SMn438十
≠
\ 千
‡\‡+
‡\
野
口
十
も、季
‡ ’
SMn443
‡\
÷ ’
\+
十
毒
600
SUS403
嚇
達 十
6GO
600
550
500
450
400
圭
\
700500 600 700500
SCr440
+捧,
鴨
、
50G 600
SCM435
峯\
竃十.
\藝
F藍9.19
津
\
CM440
訟。
、
、
o
600 700500 700600 70G 800
SNC631
毒‡\
馬\ 、
,し
勲.、
+荘、
SNCM439
\
蜜
、
SNCM447
、
\
、
、
\
逢
700500 60G 700500 600 700500 600 700530 630 730530 63G
Tempering Temperature T(oC)
Relation of fatigue limit under rotating bendingσwと, and tempering temperature 7∴
730
ぐセ700E乞
多600
b’
マセニ
聖
目500雪
.曽
罵
鋤400課
6器
qコ300警
’尾
歪2・・
十
司
・{
△
▽
◇
S25CS35C, S45C, S55C
SMn438, SMn443SCr440, SCM435. SCM440SNC631、SNCM439, SNCM447SUS304SUS430SしFS4(.〕3
◇
贈細
o
o
函 △
4〔匠) 500 600 700 800 9GO IOOO 1100 1200 玉300
Tensile Stre職gthσB(N/mm2)
Fig.20 Re垂ation of fatigue limit under rotating bendingσwb
to tensiie strength σB.
ゆ∈
目
遣
詩
,二
三
コ
睾
.曽
罵
.9
曽
β
忌日
雲
髭
500
400
3〔.}0
2〔}0
100
+ S25C
・{§認醜緒魁・} SCr44〔1、 SCM435. SCM440
SNC631,SNCM439, SNCM447△ SUS304▽ SUS430
◇SUS403 口
評口
津/ぜ
胆
。
鯨蹄諦。
o
Fig.21
400 500 60G 700 800 9〔}0 100(, 1100 120〔, 1300
つ Tensile StrengthσB(N!mmつ
Relation of fatigue lim三t under reversed tors呈onτw to
tensile strength σB.
shown in Fig.5. It can be concluded that the fatigue
strength behave substantially in the similar way to the
monotonic strength parameters,
4.2 Correlation 8etween F飢igue Stre盤gth 3nd
Mech段nical Properties
Typical correlation of fatigue s£rength to mechanic-
al properties can be fourld in the following.
Figure 20 shows the relation of fatigue limit un(ler
rotating bending to tensile strength of all the materials
teste(墨. There is c豆ear dependence on the microstruc-
tures:HTTM carbon and low alloy steels are all in a
band where mean coefncient of proportionality is
O.542with standard deviation of O.0233. S25C steels
with F/P structure and SUS304 at austenitic structure
are placed at the bottom,with the mean coefficient of
O.496and O.492, respectively, and ferritic SUS430
steels at the highest, with O.611.
Similar relations are obtained for fatigue limits
under reversed torsion, Fig.21, and under axial
loading at reversed tension-compression and at repe-
ated tension, Figs.22 and 23, respectively. The range
of scatter was not shown in these figures except for
Page 18
Basic Fadgue Propertles of JIS Steels for Machlne Structural Use 15
ρ 塁
喜
都響喜
喜
幽
700
6GO
500
400
300
200
+S25C・1§薪禽3§1鳩譲f
・l SCr440, SCM435. SCM440 SNC631,SNCM439, SNCM44 0 0(9ムSUS304vSUS430◇SUS403
〆 口
。口
o(o
’。
『『ロ
%・
蟹
。
8。o o
400 500 600 700 800 9〔}0 1000 1100 1200 1300
Tensile StrengthσB(N!mm2)
Fig.22 Relatioq o£fatigue limit under reverscd tension-
compressionσ宙to tensile s之rengthσ拾.
e駐700量
乙
36α〕
誉
コ5008
.…夕
拓
凱400響
筍き
q自3〔}0
曽
醤
歪2{沿
S25CS35C, S45C, S55C
SMn438, SMn443SCr44G. SCM435. SCM440
SNC631,SNCM439, SNCM447SUS304SUS430SUS403
o 口
0
蕪霧 o
100 150 200 250 300 350 400
V孟ckers Hardness Hレ
Fig。24 R.elation of fatigue limi宅under rotating bendingσ~v疑,
to Vickefs hardness 1ゴ「y.
ρ岳
日
賦
b5.℃=
日
コ
雪
の端
山
.9
讐
昌
9器
魯
500
400
300
200
1(瓶
v▽
塾+
△
口
。口
叱
諮。
o
o
む oo(P 8&。嗣.
%
+ S25C・川止急3§1目皿説老。
。}1認£9i際錨織霧『錨盤監447
△ SUS3(,4
▽ SUS43{[
◇ SUS403
00 5σ0 60〔》 700 800 900 1000 蓋100 1200 1300
つ Tensi聖e Strengthσ白(N/mmつ
F藝g.23 Relation of£atigue limlt under repeated tensionσb to
tenSile Strength σ后.
冷座
量
乙
ゴ
鰻
箋己
.9ρ
四
切
,2
辺
£
冨誠
撃
。
500
輔
300
200
100
十
・{
・1
S25CS35C, S45C, S55C
SMn438, SMn443SCr440, SCM435, SCM440SNC631,SNCM439, SNCM447
△ SUS304▽ SuS430◇ SUS403
巳旧
/ 〆
ゆ晒 o
麟簿
200 300 4GO 5GO 60G 700
R・tating Bending Fatigue Llmit%(N/mm2)
Fig.25 Relation of fatigue limit under reversed毛orsion恥to
fatigue llmlt under rotating bendingσ寅b・
HTTM materials, as the number of test was too small
fOr the OtherS. The relatiOn iS alWayS in the Same
tendency as seen in Fig.20, suggesting systematic
relat量ons between fatigue strengths under different
loading con(韮itions.
The results shown above imply that the fatigue limit
can be pred童cted frorn tensile strength of the mate-
rials. It should be noted however that the tensile
strength given in ordinary mill sheet is not to be
simply used for the prediction, The mill sheet reports
generally the chemical composition and typicaI
mechaRical properties on test coupons, whose s孟ze
and heat treatment conditions may not be the same as
those for the actua互situat孟on.
Figure 24 gives the relation of fatigue l孟mit under
rotating be鍛ding and Vickers hardness. The correla-
tion is excellent in this case, with negligible difference
between mater童als group of different microstructures.
Following mathematical expression can be used,
豆09(σwb)篇0.92310g(Hγ)+0.417±0.0197 (6)
where the value a負er the compound sign is standard
erroL This error corresponds to the coef負cient of
variation of 454% in σwb, telling that the 95%
con且dence interval for the estimate is 8.9% for all
materials in this case.
Similar relation is found for the other fatigue
strengths, but with some dependence on rnicrostτuc-
tures. In gase of HTTM steels, the following ratios to
Hy may be used for rough estimation of fatigue
strengths:
一 for rotating bending: 1.69
- for reversed torsion: 1。13
-for reversed tension-compression: 1.66
Fatigue strengths under reversed torsion and re一
Page 19
16 Satoshi NlsHIJI騒A
㌃700嚢
乙
♂60G崔
識 500霧
.鱒
お
400
300
200
く・
・1
・{
△
▽
◇
S25CS35C、 S45C. S55C
SMn438, SMn443SCr440, SCM435, SCM440SNC63ユ.SNCM439, SNCM447SUS3{〕4
SUS430SUS403
ノ〆
【】
勉的♂
θo
o oo
o
o
20〔} 30G 400 500 600 7〔}O
Rotating Bending Fatigue Limitσ宙b(N/mmユ)
Fig,26 Relation of fatigue limit under reversed tensiQn-
compressionσ、v to fatまgue韮im玉t under rotating bend-
mgσ尋b・
ぐ∈
ヨ
乙
も
ε
餐∈
<
圏
巴
あ
800
600
400
200
0
Fatiguc Limit Line
こ\ミ ’
、 、 800
700
490
+ S25C・l S35C, S45C, S55C
SMn438, SMn443。{
△
▽
《〉
gOO 1000
SCr4401 SCM435,SCM440SNC631,SNCM439, SNCM447
SUS304SUS430SUS403
Tensile Strength
1100N/mm2
Yield Limit Line
0 200 400 600 800 10GO 1200
Mean Stressσ出(N/mm2)
Fig。28 Fatigue墨imit diagram relati鶏g amplitudeσa and mean
σ血of ma宅erials atごifferent tensile strength levels.
ぐ已
E≡
乏
)bコ
ニ.舅
当
の器
L琴
「笏
器
一
書
琶
&
幽
500
400
300
200
1oo
琴+
口
口
口・移
。 El◇
。o
庵8も
。、盛
口 Q
ロ ロ
o
o
+ S25C lS35C・S45C、S55COiSMn438. SMn443。i SCr44〔}, SCM435.SCM440
SNC631.SNCM439、 SNCM447
△ SUS304▽ SUS43〔}◇ SUS4〔⊃3
200 3(,0 400 500 600 700
つ Revesed Tension-Compression Fatigue Llmitσ壷(N/mmっ
Relation ofねt1gue limit under repeated tensionσh to
fatigue l圭mlt unδer reversed tenslon-compressionσ雨.
800
ρ已 600葺
、
)
省4GOヨ
=鳥厳
く 200認
臼
あ
Fatiguc Limit Line
に
Fig.27
00
、
、
’、 黶@200
140
、
250
+ S25C・l S35C. S45C, S55C
SMn438. SMn443 SCr440, SCM435, SCM440・l
SNC63玉.SNCM439. SNCM447ム SUS304▽ SUS430◇ SUS403
Vickers Hardness
300 350
Yield Limlt Llne
Eig.29
200 40G 600 800 .1000 1200
Mea轟Stressσ血(N/mm2)
Fatlgue llm呈t diagram relating amplitudeσゑand mean
σ血of materials at dlfferent hardness levels.
verse(至tension-compression are plotte(i in Figs.25 and
26, respectively, against rotating bending fatigue
strength. Here again the behabior is slightly differe慌
for steels with di£ferent microstructures.
Figure 27 gives the relation between fatigure
strengths under repeated tension and under reversed
tenslon-compresslon. A general ratio of O.78 is foun(i
for HTTM steels of higher strengths, while it is
variable for steels of lower strengths and higher
ductilities,
The same data is expressed as Haigh’s diagram,Fig.
28,in relation of amplitude to mean stress of fatigue
limit for different strength levels of steels. In this
diagram, fatigue limit hnes are combined to yield limit
lines, indica重ing之hat the materials can be used without
failure in zones under each curve. The lowest curve
labeled 490 N/mm2 in tensile strength represents the
trend for S25C steels.
Figure 29 is. again the same data but expressed fof
different hardness levels of steels.
The slope of fatigue limit lines for HTTM steels is
O.267 0n average.
It is to note here that the austenitic stainless steel
SUS304 can be heated-up when cyclically Ioaded at
high frequencies. The fatigue data refered above was
obtained at enough low cyclic rates to keep specimens
at r・・m temperature28).
4.3 Cychc Parameters
In parallel to the high-cycle fatigue tests for FDS
program, strain-controled low-cycle fatigue property
was investigated for some materials conditions29). The
results were not included in the referred FDS as the ,
Page 20
Basic Fatigue Propertles of JIS Steels for Machine Structuτal Use 17
ρ霞
躍
≧
憶
召む器
bの
逗、2
・裁
鼠
Q
800
600
400
200
0
÷ S25C・{ S35C, S45C, S55C
SMn438, SMn443・{ SCr440, SCM435, SCM440 SNC631,SNCM439, SNCM447ム SUS304▽ SUS430
◇SUS403
!
/
!!
/!
1/
!ノ
o
の
陣
σ,。=0・631σ・
O oo
0 200 400 600 800 1000 1200
Tenslie S重rengεhρb(N/mm2)
Fig・30 Relation of cyclic y至e至d strengthσyc重。 tens圭le stτength
σB・
宥
昌
竃紹
惹
(800 ρセ
遷 乙 ♂600.§ε
塁ぎ
氏潟貫の4000 0
9義.§慧
儀200
+ S25C・{ S35C, S45C, S55C
SMn438, SM罷443・{ SCr440, SCM435,SCM440 SNC631, SNCM439, SNCM447ム SUS304▽ SUS430◇ SUS403
馬漏0・865σy、
o
Q o OO
◇
む ・▽申・㌃餌0.677σ,。
ノ三ゑタ恥554匁
多タノφ
0 0 100 200 300 400 500 600 700 800
Cyclic Yield Strength(lyc(N/mm2)
Fig.31 Relation of fa重lgue limi重under reversed tension-
compress呈on σ㍊ to cyclic yield strength σyc・
work was conducted in view of obtaining prehminary
data for the succeeding serles of FDS program. More
comprehensive data can be found孟n other FDSpublication17)一22), which w孟ll be subject to another
FDS TechnicaI Documents in preparation.
It is already known that the cyclic stress-strain
relationship in low-cycle regime is of substantial
importance to characterize fatigue of materials. In
fact, well-annealed materials is easy to be deformed,
as the dislocation density is low in the matrix. By the
apPlication of cyclic strains, the density is increased in
matrix and stabilized at a state reHecting the range of
strains. The materials is then cyclicaHy hardened to a
degree characteristic to the dislocation structures.
On the contrary, apPlication of cyclic strains can
decrease the dislocation density, when it was initially
at very high stages as in quenched or severely
cold-worked materials.The materials is then cyclically
softened. The stable densities of dis夏ocations in both
cases are characteristic to the strain range, and
particularly to the metallurgical structure of materials.
The stress-strain relationship of cyclically stabilized
materials ls therefore a key property reHecting the
dislocation mobility in matrix, and thus the fatigue
behavior of the materials.
St「ess-strain response of cyclically stabilized mate_
rials is determined by the incremental step test in the
present paper. Mateials, experimental conditions and
ana玉yzed results are reported in an earlier paper29).
Here wi玉l be discussed only about the relationship
between fatigue strength and cyclic yield strength,σyc,
de行ned as O.2%offset stress on the stress-strain curve
at cyclically stabilized state.
Figure 30 shows first the relatlon of cyclic yield
strength to tensile strength of test materials. Cyclic
yield was determined only for materlals conditions
where axial fatigue properties were investigated. As
seen in the 盒gure, there is a proportional re董ation
between the two as a whole. In closer view, however,
the coef費cient of proportionality童s somewhat higher
for three stainless steels,詑. ferritlc SUS430, austenitic
SUS304, and martensitic SUS403, than the other
HTTM carbon and low alloy steels.
Figure 31 compares axial fatigue limit under re-
versed tension-compression and cyclic y童eld strength.
It is to note that魚e fatigue Iimit is systematically
lower than the cyclic yield strength with varying
degrees for different microstructural groups of steels,
In this case, different proportionahties are disting-
uishe(玉, as indicated in the ngure. The ratioσ穏/σyc is
- for}{Tv11M steels: 0.86
-F/Psteeis: 0.68
- austenitic steels: 055
1n conclusion, the two intrinsic character重stics, that
the cyclic yield strength is dependent on the monoto-
nic tensile strength, and that the fatigue strength is
determined by the cyclic yield strength, are cons孟一
dered to be the cause of many correlations betweeH
different monQton孟。 and cycl孟。 properties.
5。 Factors Affect韮聡g Fatig聡e Propert韮es
Here w圭ll be discussed two important factors which
Page 21
18 Satoshi N王sHIJIMA
often de蝕itively affect fatigue properties of mate-
rials. One is毛he chemical composition governing the
hardness after quench, and therefore de触ing mecha-
nical properties of HTTM s乾tels. The other is the
presence of non-meta且ic inclusions in the matrix
which provides the initiation site of fatigue cracks
through stress concentration effect.
5.】L Quench Hardenability of Steels
The hardness of a steel after quench is basica11y
de負ned by lts chemical composition. Higher contents
of carbon, chromium, nickel, etc,, are favorable for
quench hardening. It is also de負nitive玉y affected by
the cooling rate a毛the quench, More the cooling rate
is fast, rnore the hardening is effective, in general.
The core part of thick materials is often found to be
not perfectly hardened even by rapid cooling. This is
known as the mass effect in quenching,
The quench hardenabiHty can be expressed by an
index Z)1 caUed ideal critical diameter, It is an
imaginary size of cylindrical specimen, having length
a£4times of its diameter, presenting a core structure
with 50%martensite by an ideal quenching at enough
high cooling rate at materials surf孕ce. The ideal
critical diameter is one o負he parameters intrinsic to
the materials quality and independent of its size and
quenching conditions.
Ideal critical diameter of low alloy steels can be
predicted in general by the primary austenite grain
size number GS, carbon content C, and hardenability
coef負cient f(.)of each element in the steel. Note that
the term Iow alloy steehs used for steels with 5%
maximum of total alloying elements。 Following ex-
pression is used in this paper:
D∬=D/B・んズんかん〆ん。プ刃∫(mm) (7)
D∬β=(1294一α622・GS)>C
ん,=!+0.699 Si, Si≦0.40
んηr1+3,344 Mn,0.60≦Mn≦0。90
ノヒ7,.=・/+2.160 Cr, Cr≦1.30
ん。=i+3,014Mo,0,15≦Mo≦035
五v汗1+0.364Ni, Ni≦2.80
where the amount of alloy童ng element is evaluated in
mass%.Factors in each equation of the hardenability
coef負cient are derived by least squares且tting of data
in the table A30f ASTM A255 standard30).
Table 4 compares typical values of the ideal critical
Tab且e 4. Ideal Cr圭tical Diameter for Low Alloy Steels Tested
SteeI Typ圭cal cQmposition DI (mm)
S25C 025C 4
S35C 0.35C 5
S45C 0.45C 5
S55C G55C 6
SMn438 038C-15Mn 35
SMn443 0.43C-15Mn 37
SCr440 0.40C-1Cr 72
SCM435 0.35C-1Cr-0.2Mo 98
SCM440 0.40C-1Cr-0.2Mo 110
SNC631 0.31C-2.7Ni-G.8Cr 78
SNCM439 G.39G1.8Nl-0.8Cr-0.2Mo 150
SNCM447 0,47C-1.8Ni-0.8Cr-0.2Mo 165
800
ミ600塗
茎
量
曇400
200
SCM440 (φ19mm)
SCM435(φ22mm)
S35C(φ22mm)
1086420246810 Distance from Central Axis(mm)
Fig.32 Typical hardness distfibutions after quench.
diameter for the grades of steels investigated. Grain
size number GS is assumed constant for si.mplicity and
set as GS=8. It is clear that the carbon steels are far
inferior to the other low alloy steels, while SNCM
steels are superior, in the ideal critical diameter. It is
to note that this table gives only an information to
understand general trend of quench hardenability for
different steels and does not provide quantitative
index allowing to predict their賑ardness.
Figure 32 shows, as an example, the actual situation
for three grades of steels in the present work. It shows
Vickers hardness distributions of steels after qugnch
determined along an ax童s perpendicular to and at
mid-length of the cylindrical bar stock of 200 mm
long, Carbon steel S35C and Cr-Mo steel SCM 435
reveal a same high hardness at the surface, as they
hε≒ve sarne carbon content of O・35%, but present
Page 22
Basic Fatigロe Properties Qf JIS Stee互s for Machine Structural Use
different lower hardness values near the center
according to their ideal critical diameters. Another
steel SCM440, containing O.40%of carbon, gives a
higher and nat hardness distribution, proving its
higher carbon content and therefore larger ideal
critical diameter.
The different hardness after quench is in general
inherited after tempering,. and thus causes difference
in mechanical properties. In the present work, the
grain size was not greatly different between test
materials regardless of steel grades and heats/lots
from different companies, as described earlier in 2.2.
The heat-to-heat variation of quench hardenability
was found dependent almost on the variation in the
content of carbon and other alloying elements.
It would not become possible, however, to predict
final mechanical properties only from the chemical
composition, because. there are still many other
inHuencing factors, such as size and surface conditions
which also affect the cooling rate. The problem is
particularly complex for the fatigue performance,
which could definitely be changed by the presence of
non一肌etallic inclusions, as described next.
5.2 Ef6ect of Non・Metallic Inclusions
As shown earlier in 4.2,. fatigue str.ength increases
in general with increasing monotonic strength, in
apProximately proportional way. However, by more
careful observation, the scatter of fatigue.strength at
given monotonic strength is found to be asymmetric,
as can be seen for example in the relation of fatigue
limit to hardness, Fig,24. There are more data lying
19
1ower outside. of the confidence band. The reason for
this occasional drop in fatigue strength of some
heats/lots is explained.by the harmful effect of
nOn-metalliC inCIUSiOnS.
In fact, special steels as investigated in this FDS
program contain generally small amount of non-
metallic inclusions. Type, size and quantity of non-
metallic inclusions are variable according to the steel
making process and steel grades. The presence of
inclusions is in principle harmful especially for high-
cycle fatigue performance, as they can be the initia-
tion source of fatigue cracks through their stress
concentration eff6ct.
Photo l is a typical example of fatigue crack
initiated at a non-metallic inclusion. It shows the
fracture surface of rotating bending fatigue specimen
of SMn438 steel tested at 400 N/mm2 and failed at
3.46×105cycles. On low magnification view at the
left, radial lines-like feature tells that the fracture
initiated from a defect at the top surface of the
specimen;at high magnification on the right, this
defect is found to be a globular composite of
nOn-metalliC inCIUSiOnS.
For carbon and low alloy steels tested in this
program, the nQn-metallic inclusions found at the
origin of fatigue fracture are found normally as the
globular mixture of oxides of Al, Si and Ca., and other
compounds such as MnS. These elements are consi-
dered to have come into the steel during steel making
process, as they are used as de-oxidation agents or for
refractory materials.
野響町己..汐F....叩....■.:.甲-......’一’...
.麟.
L100μm ト一且10μm
Photo.1 Typical fractogr駐phy showing non-nletallic inclusion at fatigue crack initiation site.
Page 23
20 Sa宅oshi NlsHIJIMA
1.9
亀 1・8
蚤b一
ヨ 1.7
ぎ
2あ 1.6呂
艶’捲
賑L5蜜
量
髭1・4
L3
●
響
し一一.
暮
95%Con行dence Interva…
丁一三も〉華彗違i
+ \‡:\ ヘマ
ギS35C,S4,C,S55C\ こ十SCr440, SCM435, SCM440 Hv 35b
oSMn438, SMn443● SNC631
画趣言竈。き
つウ 無縫
o瀦← ■ 、
Regressedresults
Hv 230
290
350、 、
、、、
o
、、 o 、 230 290
Estimated fesults
F藍9。33
20 50 . 100 150
Defect Size 2α(μm)
Re蓋at藍on of re正ative fatigue strengξh and size o£
non-r【1eta賎ic inclusioas at fa縫gじe crack initiation si£e.
In any case, it圭s empirically known that the relative
fatigue strength is decreasing with increasing size and
number of these non-metallic particles. In v孟ew of
倉且ding quantitative lnformation, an extensive SEM
analysis was conducted on the failed specimens of
var孟ous steel grades tested at low stress levels under
rotat藍ng bending.
F量gure 33 shows the results by plotting relative
fatigue strength to V孟ckers hardness against defect
size31). Here the defect size is evaluated by averaging
the largest three diameters of non-metallic孟nclusions
found for a given heat/lot of steel resgardless of
tempering temperatures. This is because the size of
inclus孟ons contained in a specimen should vary by
chance, whereas the fatigue l童mit is determined with
several specimens as an averaged behavior. The data
is plotted tentatively at 20μm position, for steels
revealing no inclus重on at crack init玉ation site,
The relative fatigue strength is found to be 1.707 as
mean for steels without inclusions, and with O。038 as
its standard deviation. For horizontal part of the data
in the hgure, solid and broken Hnes are traced using
these data without inclusion, representing mean and
95% con負dence intervals, respectively, It can be
judge(i that the dec畜ease of strength begins at the size
of 45μm. The inclined solid and broken lines are
obtained by multi-variables analysis of data beyond 45 ノμm,by pooling them into three groups according to
Vickers hardness of mater孟als, as below 260, above
.320,and in between, Hardness values of 230,290 and
350are labeled to each豆ines to represent the three
9「oups・
Dash-dotted lines in the負gure are the predictions
by linear fracture mechanics theory assuming a
hardness dependence of fatigue threshold31). The
agreement of prediction to observation is not satisfac-
tory, because of the incertitude of the hardness
dependence of threshold data use(i in the analysis.
Similar analyses have been attempted since then by
different authors giving substantially the same trends.
It重s also to be noted that the steel SNC631 shows
obviously a higher fatigue strength in Fig.33. This
steel has nominal composition of O.31C-2.7Ni-0.8Cr
and presents a better quench hardenability as com-
pared to the other steels at the same carbon content
level.
NOn-metalliC inCIUSiOnS in SteelS are generally
evaluated by a microscopic test method in JIS. The
method is in principle the area proport孟on counting on
a metallurgical section of samples. Inclusions are
classified in three categories:type A for those
deformed by plastic work such as sul且de or silicate,
type B for those appearing in discontinuous arrays
like alumina, and type C for those found isolated as in
case of granular oxides.
For the materials investigated in the present paper,
the JIS value for each type was always less than O.05%
for any heat/lot, and less than O,1%for total of three
types. No correlation was found between these values
and relative fatigue strength described above. It is
clear that the size of 豆arge inclusions should be
evaluated for better quah負cation of steels from
fatigue point 6f v童ew. One of the attempts for this is
found ln a new standard of non-metallic inclusions test
method for spring steels32).
6. Concluding Rem3rks
From NRIM FDS publlcations the data have been
extracted and co11ectively analyzed in view of provid-
ing standard reference values on basic high-cycle
fatigue properties of Japanese steels for machine
structural use. Although the most of original data
were obtained in 1975-1980, the statistical facts and
行ndings are believed to be valid and apPlicable to a
variety of materials at present.
Page 24
Basic Fatigue Propertles of JIS Steelsξor Machi頚e Stmctural Use 21
It is however noted that the data refers only to the
hot rolled bars of 19-22 mm in diameter, heat treated
at this size, and fatigue tested as standard smooth
specimens at room temperature in air. It is recom-
mended to refer the fatigue properties in relative
values to monotonic ones, as the effect of heat
treatment may not be unique for different materials
shape and size。 Tables AI to A4 in Appendix can be
served for this purpose.
There was a rapid evolution in steel making
processes in early 1980’s in this country. Traditional
ingot casting has been replace(i by the continuous
casting in most of companies. Secondary re負ning has
become familiar today for high quality special steels.
Therefore the information may not be the same as
reported here, regarding the distribution in size and
types of non-metallic inclusions.
The present paper is an extraction of the former
publication in Japanese24). Comprehensive results of
analys孟s are to be found there and direct reference of
the or重ginal FDS will give further possibility of new
負ndings. The FDS data is available through an on-line
service of the factual materials databases by Japan
Information Center of Science and Technology.
Acknowledgments
The author is greatly indebted to many colleagues
of the National Research Institute for Metals who
shared this enormous task of Fatigue Data Sheet
Project. He apPreciates the effort of his co-worker
Akira Ishii who made all the related statistical
analysis.
Symbo且s
A :
CI):
1) :
D∬:
εσ:
Ev:ぺ1:
ノV“,:
η :
T :
δ :
δu :
σB l
儀 :
σr :
σu :
妬 :
σwb:
σyc :
σb.o:
τw :
φ :
APPENDIX
Slope of 3一ハ/curve on 韮09-log co-ordinates
Coefficient of variatior… in fatiguc streng毛h, %
Knee poiRt on 5一〈1 curve, log/>、γ
Ideal CritlCal dlameter, mm
U-notch Char影)y impact value, J/cm2
V-notch Charpy 気mpact value,」/cm2
Nurnber of cyclcs to fa玉lure
Knee point on 5-/V curve, number of cycles
Work hardening exponcnt
Tempering temperature,℃
E圭ongation,%
Uni£Orm elOngatiOn,%
TenSile Strength, N/mm2
UpPer yield strength, N/mm2
True fracture strength, N/mm2
Fatigue韮imit under repeated tenslon, N/mm2
Fatigue limit under reversed tension-compression, N/mm2
Fatigue limit under rotating bendlng, N/mm2
Cyclic yield strength, N/mm2
0.2%prooξstress, NIInm2
fatigue hmit under reversed torsion, N/mm2
Re(玉uction in area, %
Page 25
22 Satoshl N[SHu麗A
Table A1(玉). Mechanical茎)roperties of JIS steels for machine structural use, expressed as mean(upPer)and standard deviation
(lower)
Tensile propeτties Impact value
Steel
iNo. of
?eat)
Temper狽?mp?
i℃)
Up yield唐狽窒?ngth?
iN/mm2)
Proof
@streSS
iN/mm2)
Tensile
唐狽窒?ngth?
iN/mm2)
rue frac
唐狽窒?ngth?
iN/mm2)
Uniform?long’tn
@ (%)
Elon一
@ ・№≠狽撃盾氏
i%)
Reduction
奄氏@area
@ (%)
WOfk?ardehg?
xponent�
-notchC
?arpy(
v/C韮n2)�
-notcbC?arpy(
i/cm2)�
呈ckersh
≠窒п|
獅?SS
25C(
P1)�
ormal-
@lzed�
633
U�
292
P�
892
T�
803
R�
6.63
D4�
7.82
D3�
3.52
D1�
,2540
CGIG�
344
O�一�
42
V
50�755
Q�
685
Q�
504
R�
469
S6�0.71
D2�
2.32
D3�
7.13
D8�
,1920
CG25�
882
W�}�
471
T
35C(
奄Q)�
00�253
W�
193
W�
972
W�
443
R7�2.01
DG�
5.11
D9�
0.22
D2�
2040C018�
132
R�一�
271
P
50�034
P�
873
S�
502
V�
407
S5�4.01
D0�
8.11
D3�
192D0�
,2/60
C017�
332
Q�}�
08
@8
50-6
T0�
355
R�
255
S�
995
R�
439
S9�2.31
D7�
5.33
D0�
9.73
D4�
,204G
C022�
123
P�}�
272
O
50�969
V�
939
V�
625
W�
550
T2�.41
D1�
0.91
D8�
2.13
T�,1620
C04G�
.223
Q�一�
801
X
45C(
P1)�
00� 307
X�
257
U�
894
O�
,505
@40�
0.60
D8�
3.21
T�
5.52
D3�
,1760
C032�
5/3
O�
一�551
T
50�756
P�
655
R�
182
U�
455
S1�2.5G
D7�
6.61
D1�
851D6�
,1910
CG22�
742
T�~�
321
O
5G-6
T0�
349
S�
289
R�
907
R�
504
@59�
0.81
T�3.62
D8�
5.43
D6�
,!760
C034�
493
U� �
552
T
50�988
S�
988
O�
493
R�
589
@44�
.00
D8�
8.91
D5�
7.02
D9�
,1300
C036�
61
O�一�
061
R
55C(
P1)�
00�096
R�
G86
^�
501
D9�
517
Q0�.80
D4�
2.11
D.4�
092D3�
,1460
C028�
181
W� �
75
@9
50�375
P�
264
S�
611
R�
450
Q/�
1.80
D6�
5.31
D1�
4./1
D6�
,165G
C020�
461
V�一�
46
@7
5(レ6
T0�
129
R�
119
S�
538
P�
519
U5�.91
D7�
2.13
D0�
G.73
D7�
,1470
C032�
!62
X�一�
762
U
50�883
P.�
276
Q�
664
V�
594
S6�.30
D8�
9.31
T�3.33
S�,1360
C0/8�
422
T�
722
T�
831
S
Mn438(
V)�
00�565
P�
555
P�
983
R�
541
R9�.91
D1�
2.01
D6�
6.31
D9�
,1560
C017�
682
R�
971
W�
591
Q
50 ’�
202
V�
013
R�
372
V�
515
R4�L7GD6�
4.81
D2�
9.21
D7�
,1720
C014�
952
O�
261
X�
39
@9
5〔ト6
T0�
434
S�
627
Q�
016
S�
548
T0�0.01
D6�
2.22
D7�
6.53
D3�
,1550
C022�
683
P�
993
O�
602
Q
Page 26
Basic Fatigue Propertles of JIS Steels£or Machlne Structural Use
Tab藍e A1(2)
23
Tensilc proper£les Impact value
Steel
iNo. o至
?eat)
Temper
hempi。C)
Up yleld唐狽窒?ng£h?
iN/mm2)
Proof
@S£reSS
iN/mm2)
Tensile
唐狽窒?ngth?
iN/mm2)
rue frac
唐狽窒?ngth?
iN/mm2)
Uniform?long’tn
@ (%)
Elon一
@ .№¥d…on
i%)
Reductlon
撃氏@area
@ (%)
Work?arde’ng
?xponen重
V-notch
bharpyiJ/cm2)
U-notch
bharpyi」/cm2)
Vickeぎs
?ard-
@neSS
55G851
T9
829
U4
951
S8
1640
@ 38
82O.7
18.8
P.3
60.2
Q.7
0,114
O,014
108
P7
B1Q5
3G5
P0
SMn443
i12)
600743
T6
738
T6
861
S2
1575
@289.6
O.6
21.2
P.4
63.2
Q.4
G,139
O,G12
134
Q0
163
Q2
277
P0
650679
S8
664
S7
785
R6
1543
@ 38
1L6O5
24.5
P.1
66.8
P.9
0,1.6王
O,014
166
P8
玉95
P8
250
P0
550-
U50
749
W7
742
W7
865
WG
1585
@539.8
P.6
21.6
Q.6
63.4
R50,138
O,G23
136
R0
163
R4
277
Q5
550919
P9
957
R9
1054
@351756
@ 35
69O.6
16.9
O.9
60.6
Q.7
α088
O,OG6
98
P5
117
QG
335
P1
SCr440
i8)
600854
Q4
840
R1
956
Q9
玉.662
@ 37
8.4
O.8
19.3
O.9
63.1
Q20,113
O,005
128
P8
146
P8
304
@ 9
65G753
P8
753
P9
874
P6
1640
@ 33
10.1
O.7
21.3
O.5
66.7
P.5
0,133
O,OG6
157
P6
181.
P6
277
@ 4
550-
U50
790
U4
850
X0
961
V9
1686
@618.5
P519.2
Q.0
63.4
R.3
0,1玉1
O,G19
127
Q9
148
R2
305
Q5
55G1022
@ 34
1G17
@37歪G96
@4玉.
18王8
@50
7.王
O.6
16.6
P.G
6L9Q.5
0,078
O,OG6
11烹
Q7
歪32
RG
352
P0
SCM435
i14)
600897
R9
886
S0
982
R5
1741
@508.2
O.8
18.7
k265.5
Q.8
G,1GO
f,007
145
Q5
174
Q9
318
@ 9
650782
R4
777
R6
885
R1
1710
@4810.1
k121.4
P.3
69.1
Q.7
0,127
O,007
189
Q7
214
R1
285
@ 9
550-
U50
852
X9
893
P06
987
X4
1756
@ 67
8.5
P518.9
Q.3
65.5
S.G
G,101
O,021
148
S1
173
S5
318
Q9
5501055
@221G80
@31
1164
@341863
@536.8
O.7
圭6.1
P.0
59.2
Q.6
0,074
O,004
83
P7
109
Q1
371
@ 8
SCM440
i15)
600936
Q7
950
R0
1047
@33王775
@447.8
P.G
17.9
P.2
62.3
Q.3
0,096
O,005
115
P9
145
Q5
335
@ 7
650826
Q4
823
Q3
926
Q4
1691
@ 63
9.8
P.4
2G.9
P.1
65.8
P.7
0,125
O,006
156
Q4
188
P9
298
@ 7
550-
U50
898
X2
950
P09
1046
P02
1776
@898.1
P.6
18.3
Q.3
62.5
R50,099
f,022
118
R6
147
R9
335
R1
Page 27
24 Satoshi NISHIHMA
Table A1(3)
「.senslle propert蓋es Impact va墨ue
Steel
iNo. of
?eat)
Temper狽?mp?
i。C)
Up yleld唐狽窒?ngth?
iN/mm2)
Proof
@streSS
iN/mm2)
Tenslle
唐狽窒?ngth?
iN/mm2)
rue frac
唐狽窒?ngth?
iN/mm2)
Uniform?long’tn
@ (%)
Elon一
@ ■№≠萩ハon
i%)
Reduct呈on
撃氏@area
@ (%)
Work?arde’ng
?xponen?
V-notch
bharpyiJ/cm2)
U-notch
bharpyi」/cm2)
Vickers
?ard-
@neSS
550912
R2
925
R6
1001
@371751
@427.1
O.5
18.9
P.1
64.7
Q.3
0,088
f,009
123
Q5
148
R6
316
P1
SNC631
i1G)
600813
Q1
832
S2
924
S0
1704
@328.3
O.6
21.0
P.3
67.2
P.9
0,114
O,011
152
Q0
176
R2
292
P1
650746
Q4
736
Q4
849
Q3
1678
@301G.O
f.5
23.4
O.8
702P5
0,146
O,009
183
P9
213
Q9
267
@7
550-
U50
807
V3
830
W5
924
V1
1710
@4685P.3
21.1
Q.1
67.4
Q.9
0,117
O,026
153
R3
179
S2
292
Q2
5801021
@261033
@351114
@351830
@447.1
O.4
17.2
P.G
60.5
P.5
0,090
O,009
98
P1
116
P3
351
P0
SNCM439
i14)
630926
R7
916
R8
1003
@341750
@408.4
O.5
19.6
P.3
63.4
P.6
G,116
O,OG7
125
P4
152
P8
317
P0
68G820
Q7
779
P7
874
Q0
1669
@3210.6
f.5
22.9
P566.8
P.7
0,145
O,007
152
P5
186
I7
278
@5
580-
U30
905
W3
908
P09
996
P03
1749
@768.7
P519.9
Q.7
63.6
R.1
G,117
O,024
125
Q6
151
R3
315
R1
5801032
@311037
@251131
@331844
@247.1
O.2
175P.4
58.6
R50,090
O,007
88
P5
106
P7
358
@7
SNCM447
i6)
630920
P6
912
P8
1013
@271767
@ 19
8.6
O.2
2G3P.6
62.6
Q.3
G,117
ソOG5
114
Q0
140
Q2
321
@5
680830
Q2
793
P1
889
P9
1656
@32105f.2
23.4
P.6
64.6
R.0
0,141
O,008
142
Q0
173
Q2
286
@ 4
580-
U80
906
V9
914
PG2
1011
P03
1754
@828.7
P.4
20.4
Q.9
61.9
R.8
0,115
O,022
116
Q9
1.40
R4
322
R0
700 一一583
Q1
727
P9
1449
@608.4
O.7
24.O
戟D1
70.8
Q.0
G,112
f,015
一…229
R7
238
@ 6
SUS403i11)
750 ~508
Q1
676
P5
1426
@5G11.3
O.9
27.3
P.7
72.4
P.4
0,126
O,010
}}271.
Q5
221
@ 6
70G-
V50一一
545
S3
701
R1
1438
@569.9
P.7
25.7
Q271.7
k90,119
f,014
一一250
R8
23G
P1
SUS43Gi9)
Anneal-
@ ed
306
Q6
301
Q5
494
Q0
1208
@94215R.1
39フ
Q.4
75.7
R.0
0,206
O,G21
一一135
P08
170
P0
SUS304i11)
Solufn
買ムeated
一一257
P7
614
R2
1937
P34
62.0
R.1
72.1
R.3
80.8
P.6
0238O,021
一} 一154
P1
Page 28
Basic Fatigue Properties of JIS S毛eels for Macbine Structural Use 25
Tab韮e A2(1). Fatigue strength and ks罫atios of JIS steels for machlne structural use, expressed as mean(upper)and standard
devision(lower)
Steel
iNo, of
?eat)
Temper狽?mp?
i。C)
κγ σB
iN/mm2)
σ~vb
iN/mm2)
q.b
辜my
妬b
ミB
πv
gγ
細σB ㌃σwb 妬Hy 馬σB 9v
ミwb
馬σu
S25Ci11)
Nor【nal一
@ 呈zed
142.1
@ 69
489.2
Q3.8
2425P4.1
1,707
O,066
0,496
f,020
1,031
O,040
0,3G1
O,008
0,618
O,010
1,518
O,G36
0,443
O,G16
0,910
f,018
1,178
O,045
550245.3
P1.7
75G.3
R8.8
409.8
Q0.7
1,673
f,088
0,547
O,030
1,080
O,079
0,360
O,028
0,664
O,015
6002272P0.2
696.6
Q4.9
384.0
P9.0
1,692
O,073
α551
O,021
LO92O,059
α359
O,019
0,657
O,02G
1,482
ソ079α487
ソ0210,891
O,020
1,288
ソ039S35C
i12)650
2075@ 7,9
649.6
Q4.8
35G.9
Q0.6
1,692
O,G86
0,540
ソ0241,092
O,040
0,354
O,015
0,668
O,036
55(レ
U50
226.6
P8.4
698.8
T1.G
381.6
R1.3
1,685
f,081
0546ソ025
1,088
ソ0560,358
O,020
0,663
ソ023
550280.0
P8.2
861.9
T7.4
472.4
R0.3
L688O,058
G548O,G17
1,126
f,077
0,369
O,G24
α679
O,046
6002545i4.2
789.7
R9.0
4345Qユ.9
L708
O,030
0550O,010
1,137
O,073
0,365
O,022
α67!
O,041
1,616
ソG770,519
f,029
0,954
O,042
1303
O,028S45C
i11)650
231.5
@ 9,6
717.8
Q4.1
394.8
P6.5
1,705
O,032
0,550
O,014
1,123
O,G72
α364
O,021
0,663
O,036
550-
U50255.3
Q45789.8
V25433.9
R9.4
1,701
O,042
0,55G
n,013
1,129
f,068
0,366
ソG20G,671
O,038
5503G6.O
奄R.7
949.0
R35514.1
P9.0
1,681
ソ0520542f.0更3
1,140
O,032
0,368
O,010
α686
f,039
600274.6
@ 8.9
8499P9.5
461.6
P3.8
1,681
O,G39
0,543
O,013
1,132
ソ0560,366
f,014
0,684
O,036
1,653
O,111
0,534
O,034
0,998
ソ0481,264
O,055S55C
i11)65G
2465@ 6.6
760.9
P2.6
413.3
P0.1
1,678
f,047
0,543
O,015
1,097
O,042
0,355
O,010
G,664
O,041
550-
U50275.7
Q6.6
853.3
W王.3
463.0
S4.2
1,680
O,045
0,543
O.0歪3
1,123
O,045
0,363
O,012
0,678
O,036
550282.7
P3.2
871.4
R9.3
457.6
R2.6
1,618
ソ0800525O,024
1,159
O,050
0,378
f,015
α707
O,023
600259.3
P1.3
803.7
Q8.0
425.9
Q0.7
1,643
O,065
0530ソ019
1,127
O,G23
0366O,008
0,697
ソG121,574
O,105
0512O,035
0,973
O,033
1,243
O,G33SMn438
i7)650
237.0
@ 7.0
734.6
QLO386.4
Q4.7
1,630
f,083
0,526
O,G27
1,125
O,048
0,366
O,G16
0,681
O,017
550-
U50
259.7
Q1.7
803.2
U4.1
423β
R9.0
1,631
O,073
0,527
ソ0221ユ37
O,040
G,370
O,013
0,695
O,020
Page 29
26 Satoshi NIsHIJIMA
Tab監e A2(2)
Hyαvb %b 筑v 恥 恥 妬 妬 妬
Steel
iNo. of
?eat)
Temper狽?mp?
i。C)
σB
iN/mm2)
σwb
iN/mm2) Hy σB Hy σB σwb Hレ「
qv
ミB σwb σu
550304.7
@ 9.4
950.1
S6.6
499.3
R7.0
1,637
O,078
0525
O,019
1,110
O,052
0,358
O,013
0,674
f,021
6002767P0.1
8655S0.6
461.0
R2.8
L665
O,073
0532O,018
:1.142
O,030
0,364
ソ0110,676
O,017
/,629
O,087
0,519
f,022
0,694
O,036
1,265
O,022SMn443
i12)650
249.8
@ 9.8
784.1
R52419.7
Q6.4
1,679
O,044
G,535
O.Oi4
1,109
O,015
0,353
O,002
0,660
f,011
550-
U50277.0
Q4.6
866.6
V95460.G
S551,66G
n,067
0531
O,017
1,121
O,036
0,358
O,010
0,670
O,017
550334.5
P051G54.4
@ 325
553.8
Q1.8
1,657
O,087
0525O,022
1,153
O,060
α367
O,G16
0,691
O,026
600304.1
@ 7.7
9546Q6.6
507.6
@ 7.4
1,670
O,042
0532O,O13
1,126
O,G64
G,361
O,014
0,680
O,016
L664
O,G54
0533O,004
1,005
O,025
1,249
O,021SCr440
i8)650
276.4
@ 2.9
874.0
P4.2
470.4
P2.9
1,702
O,042
0538O,015
1,163
O,046
0,367
O,G11
0,686
O,026
550-
U50
305.0
Q5.3
961.0
V9.2
510.6
R7.8
玉..676
O,061
0532O,017
1,147
O,G52
0,365
O,012
G,686
O,021
550351.9
@ 8.8
1095.8
@37.4
556.4
Q7.1
1,609
O,056
0517O,015
1,100
O,021
0,357
O,008
0,697
O,041
600317.1
@ 9,1
981.6
R25528.4
Q4.4
1,666
O,059
0538O,015
1,137
O,021
G,369
O,010
G,693
O,033
1,629
O,044
0529O,G15
0,993
O,036
1240O,044SCM435
i14)650
285.1
@ 8.4
884.6
Q9.6
479.4
P7.9
1,682
f,042
0542O,011
1.玉.64
O,023
0,377
O,012
0,693
O,037
55(レ
U50
318.0
Q8.9
987.4
X3.2
524.7
S2.7
1,652
O,060
0532O,018
1,134
O,034
0,368
O,013
0,695
O,034
550370.7
@ 7.3
11635
@31.9
6005Q64
1,620
O,062
0516O,019
1,077
O,061
0,346
O,026
0,680
O,069
600335.2
@ 7.0
10473
@32.7
553.4
Q1.4
1,651
O,G46
0528O,013
1,105
O,046
0354O,022
0,677
O,051
1,674
O,110
0536O,032
1,023
O,029
1,269
O,967SCM440
i15)650
297.9
@ 6.1
925.7
Q3.8
498.7
P1.4
1,674
O,030
0539O,010
1,131
ソ0500,366
O,021
0,680
O,030
550-
U50
334.6
R0.8
10455
ハ02。4
550.9
S6.7
玉..648
O,G52
0528
O,017
1,104
O,054
0355
O,023
0,679
O,049
Page 30
Baslc Fatigue P罫opertles of JIS Steels for Machine Structural Use
Tab豆e A2(3)
Steel
iNo. of
?eat)
Temper狽?mp?
i。C)
Hγ σB
iN/mm2)
σwb
iN/mm2)
qvb
gγ
破vb
ミB
筑v
gγ
双v
ミB
筑v
ミwb
偽Hγ qv
ミB
qv
ミwb
qv
ミu
550 315.7
P1.6
10025@ 36.3
5565P9.6
1,764
f,052
0555ソ016
1,122
O,G25
0,355
ソ0060,629
f,016
600291.8
P0.5
927.1
R7.2
518.0
P4.7
1,777
O,G61
0559f,020
1ユ47
O,OG2
0,362
O,GO3
0,650
O,017
1,792
f,033
0566O,008
LO15
O,018
1,267
f,057SNC631
i10)650
267.2
@ 7.2
849.1
Q33483.7
P1.6
1,811
Oつ47
0,57G
n,G16
1,148
f,036
α364
O,010
α640
O,030
550-
U50
291.6
Q25926.2
V1.2
519.4
R3.8
1,784
O,055
0561
O,018
1,139
O,G25
G,360
O,007
G,636
f,022
580350b@ 9.7
1113.9
@35.6
593.4
Q3.0
1,692
O,044
0533O,016
L145O,026
0,36G
n,008
0,674
O,GO6
630317.2
Pα0
1002.4
D35.4
547.6
Q2.4
L727
O,062
G547O,G22
1,169
O,024
0,369
O,011
0,680
O,018
1,792
O,056.
0566O,015
1,043
O,G41
1318
O,023SNCM439
i14)68G
278.0
@ 4.6
874.7
Q0.0
478.9
P2.2
1,722
f,032
0548O,011
1,192
O,038
G,378
O,011
0,684
O,G17
580-
U80
315.3
R1.2
997.0
PG35540.G
T1.4
1,714
O,049
0,542
f,018
1,169
O,034
0369ソ012
0,679
O,014
580357.7
@ 6,0
1131.3
@345594.0
P5.9
1,661
O,056
0525O,G22
1,101
O,043
0,349
O,023
0,657
O,012
63G320.8
@’5.4
1012.8
@28.3
5405@ 9.8
1,685
ソ0420534ソ018
1,147
ソ0230,363
O,014
0,667
O,002
1,734
f,007
0,549
O,013
1,008
O,014
1,276
O,011
(6)680
2855@ 3.7
889.0
P9.7
475.2
@ 6.6
1,665
O,031
G,535
O,016
1,137
O,013
0,362
O,001
0,688
ソ026
580-
U8032王3
Rα7
1011.1
P05.2
536.6
T1.1
1,670
f,043
0,531
O,018
1,128
ソ031G,358
O,014
G,671.
O,019
700 237.9
@ 6.1
726.8
P95425.1
P6.1
1,787
O,G68
0,585
f,018
1ユ53
O,026
0,383
O,010
0,646
O,025
1,738
f,024
0,577
f,012
0974O,045
1,305
f,021
SUS403
i11)
75G220.5
@ 5,6
676.2
P4.8
3995P6.6
1,812
ソ0560,591
O,G16
1,147
O,027
0,376
O,OG6
0,628
O,020
700-
V5G229.2
P0.6
701.5
R0.9
412.3
Q0.6
1,800
O,062
0588O,017
1,150
O,025
G,379
O,009
0,637
ソG23
SUS430i9)
Anneal-
@ ed
169.9
@8.6
493.9
Q0.0
30L6P35
L777
O,071
G,611
O,0王6
1,283
f,079
α449
O,005
0,724
O,03ユ
1,759
O,068
G,616
O,009
0,993
O,018
1,352
O,042
SUS304i11)
Solut’旦
狽窒?ate?
154.0
@99613.9
R2.7
301.7
P0.0
L963
O,081
0,492
O,023
1,015
O,029
0,259
ソ0080,514
O,009
1,485
O,080
0,379
O,009
0,752
O,026
1,130
O,020
27
Page 31
28 Satoshi NiSHIJIMA
T3b藍eA3(1). Parameters for∫一ノV curves of JIS steels for machine structural use, expressed as mean(upPer)and standard
devltation(lower). See equation(4)
Rotating bending Reversed torsion
Steel
iNo. of
撃?at)
Temper狽?mp?
i℃)
Tensile
唐狽窒?ngth?
iN/mm2)
Number盾?∫一N
@curve
Slope
@オ
Fatigue
撃奄高奄買ミ雨b
iN/mm2)
Knee@ ・垂盾高煤
@D
Coeff,
魔≠窒奄≠煤fn
i%)
Number盾? 3-N
@curve
Slope
@孟
Fatigue
?mitτ宙
iN/mm2)
Knee .polnt
@D
Coeff,
魔≠窒奄≠煤fn
i%)
S25Ci11)
Normal-
@ized
4892Q3.8
110.0540
O.0047
2425P4.1
6,596
O,100
1.92
O.784
0,0702 145.0
O.0024 5.玉.
6,794
O.玉.27
4.99
O.73
550 750.3
R8.812
0.0610
O.0玉.63
409.8
Q0.7
6,049
O,075
3.91
Q.234
0.0402
O.0214
265.0
@ 9,6
6242O,076
5.79
S.97
600 6966Q4.9
120.0589
O.0132
384.0
P9.0
6,071
O,176
3.87
k924
0.0410
O.0082
248.3
@ 6.6
6,148
O,469
652R.77S35C
i亙2) 650 649.6
Q4.812
0.0549
O.OG93
350.9
Q0.6
6,222
O2213.62
P.664
0.0369
O.0179
226.8
@7.1
6,394
O,369
5.62
R.27
550-
U50
698.8
T1.036
0.0583
O.0131
38ユ.6
R1.3
6,114
O,181
3.80
H.9012
0.0394
O.O153
246.7
P7.8
6,261.
O33工.
5.98
R.70
550 861..9
T7.411
0.0647
O.0137
472.4
R0β
5,879
O,184
3.23
P.914
0.0326
O.01.月.
313.0
@ 45
6,627
O,391
4..10
Q.34
600 789.7
R9.011
0.0561
O.0101
434.5
Q1.9
6,026
O,184
3.08
P.714
0.0350
O.0152
2865
@5.0
6,420
O,039
3.92
P.91S45C
i11) 650 717.8
Q4.111
0.0529
O.0064
394.8
P656,145
O,180
2.67
P.614
0.0371
O.0079
260.3
@ 6.7
6,338
O,182
351P.Ol.
550-
U50789.8
V2.533
0.0579
O.0114
433.9
R9.4
6,016
O,209
2.99
P.7112
0.0349
O.0108
286.6
Q3.0
6。46玉.
O,259
3.84
P.68
550 949.0
R3511
G.0758
f.OI50
514.1
P9.0
5,841
O,155
2.79
P.384
0.0381
O.0142
348.8
@9,4
6421O521
3.36
O57
600 849.9
P9511
0.0685
f.0070
461.6
P3.8
5,935
O,124
238O.76
4G.0349
O.0120
3095
@8,3
6593ソ374
3.23
O55S55C
i11) 650 760.9
P2.611
0.0594
O.0112
413.3
P0.1.
6,052
O,079
2.26
P.314
G.033工
O,034
270.0
P.0.4
6,604
O,353
2.92
O.65
550-
U50
853.3
W1.333
0.0679
O.0131
463.0
S425943f,148
2.48
P.1712
0.0354
O.OlO!
309.4
R4.6
6,539
O,392
3.17
O.57
55G 871.4
R9.37
0.G828
O.G221
457.6
R2.6
5,946
O,239
6.03
Q.703
0.0386
O.0106
335.3
Q7.1
6,097
O,108
4.75
R.45
600 803.7
Q8.07
0.0715
O.0153
425.9
Q0.7
6,067
O.23工
5.61
R553
0.0429
O.0124
298.7
P6.5
6,318
f,157
6.86
R.33SMn438
i7) 650 7346Q1.0
70.0660
O.0100
386.4
Q4.7
6,255
ソ2724.53
Q.283
0.0400
O.0125
272.3
、5.7
6299O,235
4.71
Q.85
55G-
U50
8G3.2
U4.!21
0.0734
O.0172
423.3
R9.0
6,090
O,269
5.39
Q.829
0.G405
O.0104
302.1
R2.6
6238f,184
5.44
Q.99
Page 32
Baslc Fatigue Properties of JIS S重eels for Machlne Structじral Use
7ab夏eA3(2)
R.ota縫ng bend玉ng ..・ Reversed torsion
Steel
iNo. of
?eat)
Temper狽?mp?
i。C)
Tensile
棟drength
iN/mm2)
Number盾? 3一ノV
@curve
Slope
@乃
Fatlgue
¥lmlt¢.b
iN/mm2)
Knee ,pomt
@D
Coe£f.
魔≠窒奄≠煤fn
i%)
Number盾? 5一ノ>
@curve
Slope
@み
Fatigue
zimit筑v
iN/mm2)
Knee .pomt
@D
Coeff. ■varlafn
i%)
550 950.1
S6.612
0.G783
O.OlO7
499.3
R7.0
5,948
O,167
3.88
Q.274
0.0380
f.0揉.25
336.8
Q0.1
6512O,281
5.81
P93
600 865.5
Sα612
G,733
ソ01Gエ
461.G
R2.8
5,997
O,ま68
3.52
Q.464
0.G393
O.0101
3125G5.G
6,191
O,053
552P.09SMn443
i12) 650 784.1
R5.212
0,673
ソ0083419.7
Q6.4
6,090
f,174
3.05
P534
0.0386
f.0049
273.8
P356539O,200
4.76
P.64
550-
U50
866.6
V9.536
0.073G
n.0105
460.G
S556,012
O,175
348Q.09
120.0386
O.GO88
307.7
RG.9
6,414
O,246
5.36
P51
550 1054.4
@3258
0.1047
ソG216553.8
Q1.8
5,786
f,221
4.66
R.01
0.0423
f.0130
383.7
P466,423
O,2G7
3.99
Q.00
600 954.6
Q6.68
0.0829
O.0215
507.6
@7,4
5,993
O,192
327P.64
30.0584
O.0101
342.7
P1.7
6,305
O,250
438O.26SCr440
i8) 650 874.0
P4.28
0,741
O.0093
470.4
P2.9
6,025
f,065
2.91
P..68
3 α0349
f.0027
320.3
P466535O,167
3.10
k24
550-
U50961.0
V9.224
0.0872
O.0219
510.6
R7.8
5,935
O,198
3,61.
Q.249
0.0452
O.0133
348.9
RG.2
6,421
O,208
3.82
P.31
550 1095.8
@37.414
0.1055
O.0143
566.4
Q7.1
5,83歪
f,103
4.74
Q.165
0.0471
f.0124
384.4
P2.9
6507O,294
402f.88
600 981.6
R2514
0.0933
f.0133
528.4
Q4.4
5,873
O,103
358P.76
50.0427
O.0072
355.8
P1.0
6,428
O,155
5.17
P.95SCM435
i14) 650 884.6
Q9.614
0.G876
ソ0133479.4
P7.9
5,950
O,155
3.26
P.G35
0.0382
f.0033
325.G
P2.2
6,420
O3283.87
P.83
550-
U50987.4
X3242
0.0955
f.0153
524.7
S2.7
5,885
O,130
3.86
P.7915
0.G427
O.0087
355.1
Q756,452
O,253
436P.62
550 11635
@31.915
0.1069
O.0122
6005Q6.4
5,747
O,126
4.72
Q.725
0.0545
O.0153
403.2
Q0.2
638玉
O,146
4.63
P,1.8
600 玉.G47.3
@32.715
0.1015
O.02G7
553.4
Q1.4
5,802
O,159
3.89
P.885
0.G566
O.008G
374.2
P4.0
6,27G
n,254
4.3G
nフ1SCM440
i15) 650 925.7
Q3.815 α0806
O.0129
498.7
P1.4
5,982
O,106
2.9工.
ソ875
0.0533
f.0133
338.2
@ 83
6,150
O,208
3.11
O.76
550-
U50
1G455
P02.445
G.0963
O.0192
5509S6.7
5,844
O,164
3.84
Q.0715
0.0548
O.Ol.17
371.9
R0.8
6267O215
4.01
P.08
29
Page 33
30 Satoshl NISH至」蝋A
璽lab置e A3 (3)
Rotating bending Reversed tors圭on
Steel
iNlo. of
?eat)
Temper狽?mp?
i。C)
Tens圭le
唐狽窒?ngth?
iN/mm2)
Number盾? 3-2V
@curve
Slope
@A
Fatigue
撃奄高奄買ミ轍,
iN/mm2)
Knee@ ・oOInt
@D
Coeff.
魔≠窒奄≠煤fn
i%)
Number盾? 5一ノ>
@curve
Slope
@A
Fat重gue
撃奄高奄買ムW
iN/mm2)
Knee@ ←oOmt@D
Coeff,
魔≠窒奄≠煤fn
i%)
550 1GO2.5
@36.310
0.0926
O.0217
5565P9.6
5,874
O,123
3.69
P.233
0.0574
O.0073
349.0
P7.1
6,374
O,114
3.94
O.86
600 927.1.
R72/G
G.0767
O.0084
518.0
P476,070
O,213
3.03
O.713
0.0474
O.0058
33G.0
@ 9.5
6,457
f,132
353O.36SNC631
i10) 650 849.1
Q3.310
0,754
ソ0076483.7
P1.6
6,013
O,168
256O92
30,485
O.0056
304.7
P1.5
6,440
O,068
3.00
O.52
550-
U50
9262V!.2
300.G816
O.0158
519.4
R3.8
5,986
f,186
3.09
P.059
0.0511
O.0072
3279Q2.4
6,424
O,10!
3.49
O.67
580 1113.9
@35.614
0.0990
f.0158
593.4
Q3.0
5,812
O,124
3.40
P544
0.0449
O.0061
396.8
@8.8
6,422
O,134
4.03
P.22
630 ま002.4
@35.414
0.0891
O.0133
547.6
Q2.4
5,860
O,177
3.15
P..24
40.G474
O.0136
365.5
@8.フ
6,297
O,281
3.60
O.86SNCM439
i14) 68G 874.7
Q0.014
0.0717
O.0158
4789P22
6,111
O,168
2.70
P.174
0.03G9
f.0066
328.5
P296,345
O,142
2.82
O.83
580-
U80
997.0
P03542
0.G866
O.0186
54G.0
T1.4
5,928
O,203
3.G8
P.3312
0.0411
O.0114
363.6
R0.6
6,355
O,186
3.48
P.03
580 1131.3
@3456
G.1040
f.0160
594.0
P595,737
O,137
6.82
R.542
0.0574
O.0090
393.5
P6.3
6,396
f,075
4.95
O.63
630 1012.8
@28.36
0.0933
O,147
5405
@9.8
5,857
O,G99
424Q.48
20.0470
f.0128
367.0
@4.2
6β45
O2G62.29
P.14SNCM447
i6) 680 889.0
P9.76
0.G742
O.G103
475.2
@ 6.6
6,094
f,095
3,1玉
P.782
0.0355
ソOG82323.5
@ 92
6448O,481
324O.11
580-
U8G
1G11.1
P05.218 α0905
f.0182
536.6
T1ユ
5,896
O,185
4.72
R.006 α466
O.0127
361.3
R2.8
6,396
f,241
3.49
P.34
70G 726.8
P9.511
0.0639
ソ0078425.1
P6.1
6239O,213
2.工9
O.614
0.0376
O.0042
274β
P0.8
6743
O,301
2.45
O53SUS403
i1め
750 676.2
P4.811
0.G552
O.0067
399.5
P6.6
6,287
O,170
250O.85
40.0380
O.0049
252.0
@3.4
6,911
O,147
3.19
O56
700-
V50
7015R0.9
220.0595
f.0083
412.3
Qα6
6263
O,190
2.35
O.748
0.0378
O.0042
263.1
P4.0
6,827
O,237
2.82
O.64
SUS430
i9)
nnea}一
@ed493.9
Q0.09
0.0585
f,134
301.6
P356723O,119
2.86
O.833
0.0460
O.0036
218.3
@ 1.5
6,913
O,087
4.20
O.69
SUS304iエ.1)
Solut’n
狽窒?ate?
6139R2.7.
110.G539
O.0074
301.7
PG.0
5,417
f,162
2.14
O.814
0.0367
O.OG51
1568
@5.9
5,862
O,401
2.72
P.57
Page 34
Baslc Fatigue Properties of JIS Steels for Machine Structural Use
Tab瞳e A3(4)
Reversed tension-compression Repeated te罰sion
Steel
iNo. of
?eat)
Temper狽?mρ
i。C)
Tensile
唐狽窒?n帥?
iN/mm2)
Number渚、3一ムr
@curve
Slope
@溢
Fat呈gue
撃撃高奄買ミ磁
iN/mm2)
Knee ,PO】醗
@D
Coeff.
魔≠窒奄≠煤fn
i%)
Number盾? 3一ノ>
@Curve
S韮ope
@A
Fa毛lgue
撃撃高奄買ミu
iN./mm2)
Knee ,pomt
@D
Cocff,
魔≠窒撃≠煤fn
i%)
S25Ci11)
Norma1-
@ized489.2
Q3.84
0.0732
O.G233
2135
@5.8
5,925
O,301
3.55
P.414
0.0449
O.G167
181.3
@3.3
6,688
O2183.05
P.88
S35Ciま2)
600 696.6
Q494
0.0428
O.OG95
337.0
P495,718
O,369
4.75
Q.474
0.0627
O.0063
261.8
P256,126
O,191
4.20
Q.08
S45Ci11)
600 789.7
R9.04
G.0415
O.0198
4085R7.6
5,613
O,644
2.46
f344
0.0487
f.0214
313.5
Q7.1
6,101
O,434
2.46
f.39
S55Ci11)
6GO 849.9
P954
0.0312
O.0092
452.3
R0.6
5,788
O,274
2.89
P.284
0.G317
O.0164
358.G
Q5.0
5,894
O,679
2.35
ソ46
SMn438i7)
600 803.7
Q8.03
0.0349
O.0271
417.7
S2.7
6,250
O,322
6.08
T.723
0.0511
f.0234
335フ
Q6.0
5,792
O,151
4.83
S.29
SMn443i12)
600 8655
Sα64
0.0473
ソ0178446.0
R955,668
O,255
4.73
R354
0.0341
ソ01193525R0.7
6,208
O,070
4.67
Qフ9
SCr440
i8)
600 954.6
Q6.63
0.0378
O.0172
506.7
P8.8
5,777
O,146
4.51
R.933
0.0408
f.0104
4G5.7
@ 95
5,857
O,099
3.75
R.32
SCM435i玉4)
600 981.6
R255
0.043G
ソ0093509.8
P4.0
6,130
O,390
5.01
Q.155
0.0441
ソGO87411.4
P5.9
5973O,434
4.26
Q.83
SCM440i15)
600 1047.3
@32.75
0.0368
O.0143
567.6
S4.5
5,968
O,475
3.70
P.895
0.0534
f.0206
447.4
Q7.5
5,877
O,297
3.84
Q22
SNC631i10)
600 927.1
R7.23 α0321
O.OG86
5153P1.0
6,260
O,052
235O.09
30.0406
O.G122
407.3
Q4.0
5,798
O,145
1.60
O.36
SNCM439i14)
630 1002.4
@35.44
G.0344
O.0100
560.3
ハ3.7
5,938
O,078
2.10
O564
0.0343
O.0111
425.3
P6.3
6,088
O,082
1.82
O.65
SNCM447i6)
63G 王G12.8
@28,32
0.G322
O.0062
555.G
@2.8
6,130
O,099
2.16
O.432
G.0290
O.G177
435.O
@ I.4
6,035
Oβ75
1.76
O.63
SUS403i11)
700 726.8
P954
0.0297
f.0057
413.3
ハ5.3
6,123
O,298
2.17
O.974
0.0499
O.0140
316.8
P1.8
5,947
f,276
296O.30
SUS430
i9)
Anneaレ
@ ed
493.9
Q0.03
0.G18G
n.0025
299.7
@ 8,4
6,513
O,422
2.03
O.413
0.0481
O.G372
222.0
P3.G
6,445
O,114
2.77
O.63
SUS304i11)
Solut’n
狽窒?ate?
613.9
R2.74
0.0701
O.0281
229.3
P1.4
5,178
O,216
3.44
O.6G4
0.1499
O.0747
203つ
P1.5
5,653
f,113
4.22
P55
31
Page 35
32 Satoshi NIsHIJIMA
Table A4(1). Parameters for normal量zed∫一く1 curves of JIS steels for machine structural use. See equation(4)
Relat玉ve tO tenSile Strength Relative to Vickers hardness
Stee1
iNo. of
№?at)
Temper狽?mp?
iQC)
Loadingモ盾獅р沿黶
@ ,@tlon
Number盾? data
Slope
@A
Fatigue
pimlt
@σ/σh
Knee@ ■oOlnt
@D
Coeff.
魔≠窒奄≠煤fn
i%)
Slope
@A
Fatigue
撃奄高縁d
ミ/Hγ
Knee ,pomt
@D
Coeff.
魔≠窒奄≠煤fn
i%)
S25C Normal-@ized
Rot. bend
sorsion
sens. comp.
yero Tens,
207
V0
U6
U2
G.0596
O.0642
O.0767
O.0413
⑪5061.
O.3034
O.44G2
O.3785
(~.3981
U.9050
T.8533
U.5854
6,457
T,511
T,842
S234
0.G555
O.G669
O.0688
O.0466
1.7253
P.0241
k5玉.66
P.2641
65059
U.9250
T.9156
U.7103
4987U,405
S565T,0!3
S35C
55〔}一650
T50-650
@ 600
@ 60G
Rot, bend
sorsion
sens. comp.
yero Tens.
745
Q13
T9
U1
0.G630
O.0453
O.0469
O.0583
0.5516
ソ3642
O.4938
f.3865
5.9902
T9362T5955
U.0453
5,971
V,786
U,4!8
T,178
0.0638
O.0479
O.G523
O.0678
1.6988
P.0995
P.5025
P,171.9
5.9965
T.9888
T.5729
U.OG36
6338W,413
V,395
U,746
S45C550-650
T5〔レ650
@ 600
@ 600
Rot, bend
sorsion
sens. comp.
yero Tens.
667
Q11
T8
U2
0.0509
O.G389
O.05G7
O.08G2
05598
O.3678
O5187
O.40i4
6.0827
U.2866
T.3256
T5728
4,495
U,351
V,232
T,401
G.0505
O.0406
O.0445
O.G536
1.7074
P.1377
P.6280
P.2466
6.0745
U.2392
T.3247
T.8393
4,655
V,183
U,176
T,209
S55C550-650
T5〔}一650
@ 600
@ 600
Rot. bend
sorsion
sens. comp.
yero Tens.
652
Q14
U0
U0
0.0632
O.0379
O.G371
O.05G2
05396
O.3634
O.5303
O.4268
6.0326
U.3783
T.8277
T.5576
3bOOS,717
V,123
S,401.
0.0644
O.0368
O.0376
O.0296
1.6792
P..1,169
P.615/
P.2967
5.975i
U.4943
U.0054
U.1250
3,454
T,459
V,!75
R,822
SMn438550-650
T50-650
@ 600
@ 600
RQt. bead
sorsion
sens. comp.
yero Tens.
405
P66
T0
S1
0.0689
O.0421
O.0508
O.G702
05247
O.3709
O5214
O,4B4
6.1613
U.1752
T.7385
T.6219
6,779
U,646
P0,643
U,490
0.07G2
f.0428
O.0501
O.0673
i..6446
P.1333
P5999
P.2608
6.0696
U.2285
T.7437
T.6986
7,152
V,010
P0,366
T,872
SMn443550-650
T50-650
@ 600
@ 600
Rot. bend
sors孟on
sens, comp.
yero Tens.
685
Q10
U8
T7
0.0692
O.0362
O.0462
O.G440
G5270
f.3610
O5233
O.4171
6.1067
U.3754
T.6182
T.8966
5,021
T,824
U,694
T,867
0.G701
O.〔〕369
f.0527
O.0506
1.6533
P.1289
D1.6413
P.3080
6.0868
U.3628
T5705
T.8099
5,877
U,26G
V.5i.0
U,935
SCr440550-650
T50-650
@ 600
@ 600
Rot. bend
sorslon.
sens. comp.
yero Tens.
453
P55
S9
S9
G.0800
O.0396
O.0403
O.G429
05312
O.3652
O5355
O.4397
5.9819
U.5428
T.6353
T5066
4,808
T,090
T,101
T,721
0.G815
O.0427
f.0444
O.0435
1.6649
P.1443
堰D6431
P.3239
5,996
U5205
T.7166
T.9066
5,144
U,122
T,829
T,231
SCM435550-650
T50-65G
@ 600
@ 600
Rot. bend
sorslon
sens. cOmp,
yero Tens.
829
Q77
W2
V8
G.0950
O.0400
O.0405
Oつ493
0.5310
f.3680
O5385O.43玉1
5.89G6
U5353
T.9839
T.8153
5,378
T,346
T,579
T,272
0,G91.8
O.0388
O.0391
f.0511
1.6442
P.1325
P.6334
P.3071
5.9318
U5715
U.1589
T.9231
5,747
T,172
T,700
T,661
SCM440550-650
T50め50
@ 60G
@ 600
Rot, bend
sorsion
sens. comp.
yero Tens.
897
Q8G
W1
W1
0.0925
f.0642
O.0419
O.0481
05273O3608
f.5364
O.4264
5.866G
U.0746
T.9277
T.8667
6,193
W,291
U,344
U,206
0.0873
O.0584
O.0452
O.0464
1.6362
P.1200
P.6684
P.3091
5.9442
U.1150
T9200
U.0649
6,164
U,238
U,699
T,923
SNC63158〔}一680
T80-68G
@ 63G
@ 630
Rot. bend
sorsion
sens. comp.
yero Tens,
581
P72
S5
S7
0.G801
f.0475
f.0320
O.0412
05613
O.3619
f.565フ
O.4465
5.9933
U.4441.
U.3249
T.815工
4,012
R,864
Q992S,005
0.0821
O.G475
O.G315
O.0388
1.7892
P.1453
P.78/2
k4094
5.9522
U.4437
U3860
T.8806
4,112
R,900
Q,912
R,651
Page 36
Basic Fatlg蟻e Propertles of JIS Steels for MachiRe Structural Use 33
Tab韮e A4(2)
RelatiVe tO tenSi韮e Strength Relative to Vickαs hardness
Steel
iNo. of
?eat)
Temper狽?mp?
i。C)
Loadingモ盾獅р堰|
@tion
Number盾? data
Slope
@A
Fa宅igue
撃奄黒E
O1σ倉
Knee ・POmt
@D
COef£.
魔≠窒奄<rn
i%)
Slope
@A
Fatigue
撃奄高撃買
ミ/Hy
Knee ■POInt
@D
Coe££.
魔≠窒奄≠煤fn
i%)
SNCM439580-680
T80-68G
@ 630
@ 630
Rot. bend
sorsio罰
sens. comp.
yero Tens.
800
Q13
U8
U3
0.0797
O.0418
f.0298
O.0380
05356
f.3704
O.5625
O.4383
6.0506
U.3279
U.1766
T.76G8
5,018
S,466
Q,758
Q,390
G.0783
O.0399
O.G403
O.0404
1.6840
P.1653
P.7919
P.3771
60848
U.3942
T.8127
T.7953
4,734
S,043
Q,980
R,016
SNCM44758G-680
T80-680
@ 63G
@ 630
Rot. bend
sorslon
sens. comp.
yero Tens.
355
P13
R3
R1
0.0831
O.0457
O.0486
f.0261
05259
O.3561
O.5446
O.4293
60109
U.4738
T.9261
U.0670
6,712
U,175
T,085
Q,595
0.0800
f.0464
O.0344
O.G259
1.6495
P.1216
P.7363
P.3555
6.G482
U.4254
U.0805
U.0772
5,903
S,831
Q,817
Q,305
SUS40370G-750
V00-750
@ 70G
@ 700
Rot. bend
sors星on
sens. comp.
yero Tens.
315
P32
T6
T6
0.G600
ソ0380
O.0307
O.0480
058玉.6
O.3836
O.5724
O.4395
63234
U.6910
U.2157
T.9885
3,042
R,286
Q,330
R,238
0.0608
f.0378
O.03G9
O.0501
1.7748
P.1511
P.7289
P326G
6.3390
U.8165
U.1599
T.9591
3,399
R,479
Q,464
R,897
SUS430 Anneaレ
@ ed
Rot. bend
sorslon
sens. co組P・
yero Tens,
ま38
T0
R9
R9
0.G587
O.0455
O.0203
O.0542
0.6114
O.4447
O.6169
f.4583
67337
V.0002
U.4798
U.2960
4,553
S,01G
S,001
S,223
0.0658
O.0544
f.0026
O.0566
1.7666
P.2547
P.7470
s..3067
6.7196
U.9269
U.4824
U.3106
6,956
V,895
T,342
T,435
SUS304 Solut’n
ムreated
Rot. bend
sorsion
sens. com碧.
yero Tens.
141
R5
T2
T5
0.0574
O.G360
O.0587
O.1209
0.4921
O2629
O.3754
O.3293
5.4363
T.7347
T.3394
T.7501
5,636
T,915
R,293
S,115
0.0612
O.0389
f.0562
O.1236
1.9661
P.0182
P4545
P.2846
5.4133
T.8252
T511G
T.7529
6,268
S,486
U,133
V,G83
Refbrences
1)Program of the Fatigue Da重a Shee乞Project for En-
gineering Materlals Manufactured in Japan, NR茎M
Fatigue Data Shee£, No。0(1978), pp.8.
2)Data Shee重on Fatigue Properties of S25C(0.25C)Steel
for Machine Stmctural Use,NRIM Fatigue Data Sheet,
No.1 (1978), pp。8.
3)Da£a Sheet on Fa£igue Properties of S35C(0。35C)S宅eel
for Machine Structural Use, NRIM Fatigue Data Sheet,
No.2(1978), pp.14.
4)Data Sheet on Fatigue Properties of S45C(0.45C)Steel
for Machine S曲ctural Use,NR王M Fatigue Data Sheet,
No.3(1978), pp.14.
5)Data Sheeωn Fatigue Prope由es of S55C(0.55C)Steel
食)rMachine Structural Use,NRIM Fatlgue Data Shee{,
No.4(1978), pp。藁4,
6)Data Sheet on Fadgue Proper重ies of SCr440(0.40C-
1Cr)Steel for Machine Structural Use, NRM Fatigue
Data Sheet, No.8(1979), pp.14.
7)Data Sheet on Fatigue Properties of SCM435(0。35C-
1Cr-0.2Mo)Stee1食)r Machine Struc亡ural Use, NRIM
Fatigue Data Sheet, No.9(1979), pp.16.
8)Data Sheet on Fatigue Propertles of SCM440(0.40C-
1Cr-0.2Mo)S£eel£or Machine Structural Use, NR王M
Fatigue Data Sheet, No.10 (1979), pp.16.
9)Data Sheet on Fatigue Properdes of SMn 438(0.38C-
1.5Mn)Stee1£or Machine Structural Use, NRIM
Fatigue Data Shee{, No.16(1980), pp.14.
10)Data Shee{on Fatigue Properties of SMn443(0。43C-
15Mn)Steel for Machine Structural Use, NRIM
Fatigue Data Sheet, No.17(1980), pp.14。
11)Data Sheet on Fatigue Properties of SNC631(0.31C-
2.7Ni-0.8Cr)Steel for Machine Structural Use, NR.IM
Fatigue Data Sheet, No,24(1981), pp.14.
12)Data Sheet on Fatigue Properties of SNCM439 (0.39C1.8Ni-0.8Cr-0.2Mo)Steel for Machine StructuraI
Use,NRIM Fatigue Data Sheet, No.25(1981),ppユ6.
13)Data Sheet o無Fatigue Properties of SNCM447(0。47C-
1.8Ni-0.8Cr-0.2周目)Steei fbr Machine Structural Use,
NRIM Fatigue Data Shee重, No。26(19819, pp.12.
14)Data Sheet on Fatigue Properties of SUS430(17Cr)
Stainless Steel Bars for Machine Structural Use,NRIM
Fatigue Data Sheet, No.29(1982), pp.8,
15)Data Shee宅on Fatigue Properties of SUS403(12Cr)
Stainless Steel Bars for Machine Stru伽ra1{Jse,NRIM
Fatigue Da重a Sheet, No.30(1982), pp。12.
Page 37
34 SatGshi NISHIJ【MA
16)Data Sheet on Fatigue Properties of SUS303(18Cr-
8Ni)Stainless Steel Bars for Machine S{ructural Use,
NR.IM Fatigue Data Sheet, No.33σ983), pp.10.
17)Data Shee重on Low-Cycle Fat重gue Propertles of S25C
(0.25C)Steel for Machine Struαural Use, NRIM
Fa宅igue Data Shee重, Nα38(1984), pp.8.
18)Data Shee重on Low-Cycle Fat重gue Proper重至es of S35C
(0。35C)Steel for Machine S£ruc加ral Use, NR.IM
Fa£igue Data Sheet, No.39(1984), pp.18.
19)Data Sheet on Low-Cycle Fat呈gue Proper毛重es of S45C
(0..45C)Steel for Machine Struc{ural Use, NRIM
Fat圭gue Data Sheet, No.44(1985), pp.18.
20)Data Sheeωn Low-Cycle Fatigue Properties of SCr440
(0.40C-1Cr)S重eel for Machlne Structural Use, NRIM
Fatlgue Da重a Shee毛, No.45(1985), pp.14.
21)Data Sheet on Low-Cycle Fadgue Proper重ies oぜ
SCM435(0.35C-1Cr-0。2Mo)S£eel for Machine Structu-
ral Use, NRIM Fatigue Data Shee重, No.52(1986),pp.
16.
22)Data Sheet on Low-Cyc圭e Fadgue Proper毛ies of
SNCM439(0.39C-1.8Ni1Cr-0.2Mo)S毛eel至or Machlne
Structural Use, NRIM Fatigue Data Sheet, No.56
σg87), p茎). 16.
23)Nlshijima, S., Mechanlcal Properties and Fa宅igue
Strength of JIS Carbon, Chrom壼um and Chromium-
Molybdenum Steels for Machine Structural Use,NRIM
Fatigue Data Sheeゼrechn孟cal Documen重, in Japanese,
No.1(198!), pp.93.
24)Nishilima, S.,Ishil, A., Kanazawa, K.,Matsuoka, S.,
and Masuda, C., Fundamental Fatlgue Properties of
JIS Steels for Machine Structural Use, NRIM Fatigue
Data Sheet Technical Documents, in Japanese, No.5
(1989),pp. 161.
25)N童shijima, S., Statistical Analysis o£Slnall Samp玉e
Fatigue Da重a, in‘‘Statis重ica重Research on Fatigue and
Fracture”, Tanaka, T., Nish壼jima, S., and王ch童kawa,
M,£ds, Current Japanese Materials Research, Soc.
Mat. ScL, Japan, VoL 2(1987), pp.1-19, Elsevier
Applied Sc童.
26)Nishilima, S. and Ishii, A.,Parametric Representa纏on
and Ana墨ys童s of S-N Data wlth Bl-Li訟ear Curve Fitting,
Trans. NRIM,29(1987), pp.21-29.
27)Standard Me癒od o釜Statistical Fa重igue Testing, JSME
SOO2-81(1981), pp.159, Japan Soc. Mech. Engineers.
28)Takeuchi,E,Matsuoka, S.,and Nishijima, S.,Fatigue
Properties of SUS304 Steel at Room Temperature in
Laboratory Air, Trans, NRIM,30(1988),pp。138-145。
29)Tanaka, K.,Nishijima, S.,Matsuoka, S.,Abe, T,,and
Kouzu, E,Low-and High-Cycle Fatigue Ploperdes of
Various Stee至s Sρeci且ed in JIS for Machine S{ructural
Use,Fatigue Engng. Mat, Struct.,4(1981),pp.97-108.
30)ASTM A 255-1967, S£andard Method of E難d-Quench
Test for】Elardenabi圭i£y of S重eels,(1967).
31)N重shilima, S,, Tanaka, K., and Sulniyoshi, H., Proc.
6th Int. Conf, Fracture, India,3 (1984),1719.
32)JSMA Standard, Microscoplc Testing Method of Non-
Me£a歪lic Inclusions for Spring Steels, Spring Manufaひ
宅urers Assoc., Japan.
Page 38
Basic Fatigue Properties of JIS Steels
for Machine Structural Use
by
Satoshi NISHIJIMA
NRIM Special Report (Technical Report)
No.93一{)2
Date of issue:31 March,1993
Editorial Colnmittee:
Norio NAGATA__Cha廿man
Saburo MATSUOKA。.Cochai㎜an Fujio ABE
Hirohisa IIZUKA
Kazuo KADOWAKI
Mikihiko KOBAYASHI
Yoshio SAKKA
Masao TAKEYAMA Kohei YAGISAWA
Publisher, Contact:
Hiroshi MATSUOKA
PIanning Section, Administration Division
National Research Institute for Metals
2-3-12,Nakameguro, Meguroku, Tokyo 153, Japan
Phone十81-3-3719-2271 Fax十81-3-3792-3337
Copyright◎1993
by
National Research Institute for Metals
Director-General Dr.】くazuyoshi NII
P盛nted by Tokyo Press Co.,Ltd.
Page 39
Basic Fatigue Properties of JIS Steels for Machine Structural Use
by
Satoshi NISH:IJIMA
NRIM Special Report (Technical Report)
No.93-02
Contents
Abstract....................一.....99..............................願...................ロ.ロ........9畳9願.......9............匿
1.Introduction,..................噛.........99畳..願............,層.......9........................-.......ロ...9...........
2.Materials Sampling and Test Procedures.__._....___._.._.___.._._...____.
2.1Test Materials....._._..._........._.._.___._._.....….・....….・.・...・・….…....….・・...
2.2Heat Treatments......._.._._._........_........._.......,.・…....…・.・…・...・.・.…・...….…・
2,3Test Procedures......__.._............__..._..._.,.__........_.................._._.._
2.3.1Mechanical Properties Tests____..______..._..___._...__.____.
2.3.2Fatigue Properties Tests_____.____..__._._____...__...___.._
2.4Data Analyses__.._._______...・…・・………・.・………・………・…・…・……………・
2.4.1Simultaneous Regression_____.__.____.....____.._.___..___..
2.4.2Analysis of 5-2V Curve.....______。__.____..____.__.._____...
3.Reference Mechanical Properties of JIS Steels__.._..__.____.____.__..__.
ノ 3.1Variation of Properties due to Heat Treatment.___._.._____.._.___.___.
3.2Correlation Between Machanical Properties..._____._.._._____._.____
3.2.l Monotonic Strength Parameters___..._______._.____.____._._
3.2.2Monotonic Ductility Parameters...__.___._.__..____.__.____..._
4.Reference Fatigue Properties of JIS Steels_....______.______..._._____.
4.1Variation of Fatigue Strength due to Heat Treatment。......._.__..._....____...._.
4.2Correlation Between Fatigue Strength and Mechanical Properties..__._.___..._._
4.3CycHc Parameters_.._...__._.__...,____....._____..........____._....
5.Factors Affecting Fatigue Properties._._.____._.__.__.__.._____._.__
5.1Quench Hardenability of Steels____.._._・__.._...______._____._.。.
5.2Effect of Non-Metallic Inclusions._..........._..._.._._....._..........._.._..._....._
6.Concluding Remarks_.._______._..__..__.......___......_.____......_.
Ac㎞owledgements__._...______.......___...一._..._._._._...___.......__.
References......._.....一一...._._....._._............__....,...._......._.._..._..._....._。.....
1
2
2
2
3
5
5
5
6
6
7
8
8
10
10
11
13
13
13
16
17
17
19
20
21
33