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IS 9175-20 (1986): Rationalized Steels for Automobile andAncillary Industry, Mechanical and Physical Properties -Part 20 20MnCr5 Grade steel [MTD 16: Alloy Steels andForgings]
IS : 9175 ( Part 20 ) - 1986
Indian Standard RATIONALIZED STEELS FOR
THE AUTOMOBILE AND ANCILLARY INDUSTRY
PART 20 MECHANICAL AND PHYSICAL PROPERTIES OF
20MnCr5 GRADE STEEL
Co-ordinating Committee on Materials for Automobiles, SMDC 31
Chkrnan Rspresmting
SHRI C. V. TIKE~AR Tatn Engineering & Locomotive Co Ltd, Jamrhedpur
Members
SIIRJ A. K. ROY ( Allcrnatc to Shri C. V. Tikekar )
SHRI V. P. A~RAWAL Steel Authority of India Ltd ( Rourkela Steel Plant ), Rourkela
SHI~I A. K. MALHOTRA ( Alternots ) SHRI R. BR~ARI All India Automobile and Ancillary Industries
Association, Bombay SH~I S. PANIKAR ( Altarnata )
SHRI R. BHATTACHARYYA Guest Keen Williams Ltd. Calcutta SHRI A. T. BORATE Premier Automobiles Ltd, Bombay
SHRI J. M. SRAH ( Altsrnats ) SRHI R. R. CONTRACTOR Automobile Products of India Ltd, Bombay
SHRI V. A. RAJAMONEY ( Alternate ) SIIRI S. P.DEY Hindustan Motors Ltd, West Bengal SHRI V. GOPAL Lucas-TVS Ltd, Madras
SHRI K. S. SUBRA~ANIAS ( Alternate J SHRI S. C. GUPTA ~~ Tata Iron and Steel Co Ltd, Jamshedpur
SHRI A. N. MITRA ( Attmatc ) SHRI D. N. GUPTA Bokaro Steel Plant ( SAIL ), Bokaro SHRI H. A. TAIEIN~HA~I Mahindra and Mahindra Ltd, Bombay
SRR~ S.-RABfAaECANuRAN( Ahmats) SHRI R. C. JEA Steel Authority of India Ltd ( ASP ), Durgapur
SARA R. C. MODI ( Alternate ) SHRI M. L. KATYAL Bajaj Auto Limited, Pune
SHRI S. R. SALCXA ( Ahrnatc ) SHR~ S. S. LAKHUNDI Bharat Forge Co Ltd, Pune
DR M. K. S. CHERUKUHN ( Altarnutr )
( Cmtinuad en page 2 )
@ Cqyrigbr 1986 INDIAN STANDARDS INSTITUTION
Thii publication is protected under the Indian Copyright Act ( XIV of 1957 ) and reproduction h whole or in part by any means except with written permission of the publisher ahall be deemed to be an infringement of copyright under the said Act.
IS : 9f7!5 ( Part 28 ) - 1986
( C6ntinucdfram bug6 1 )
Mambws &f.JrUSU?ltin~ SHRI S. C. MAHINDX~U Chief Inspectorate of Heavy Vehicles, Avadi
SHSI P. SOMASUNDRAM ( Altawulu ) C0L.P. M. MENON Directorate of Standardination ( DC1 ), New Delhi Da V. PLNDURAN~A Tractors and Farm Equipment Ltd, Madras
Ssm1T.K. SUBBARAYAN(A~~~~~) Saar K. PARTHASARTHY Ashok Leyland Ltd, Madras
SERI T. S. SUDARSRAN ( Altumntu ) DR P. G. PATANKAR Central Institute of Road Transport, Pune
SERI L. SHANTARAM ( A~ternutc ) DR R. V. PATEY Mahindra Ugine Steel Co Ltd, Bombay
SERI R. N. SINQH ( Aft6matc ) SHR~ G. R. PRAKASE Visvesvaraya Iron & Steel Ltd, Bhadravati
SEIRI B. HARIDASAOHAR ( Altcnzats ) SHRI R. RA~HAPAN Enfield India Ltd, Tiruvottiyur
SERI T. M. BALARAYAN ( Alturnata ) Sa~r AJAY KUMAR RAMAN Escorts Ltd, Faridabad
SERI S. D. KHANNA ( Altsrnota ) DaV. RAMASWAMY Research & Development Centre for Iron and Steel
SHRI S. R. MEDI~ATTA ( Alf6rnUf6 ) SAIL ( R & D-Centre ), Ranchi
SHRI C. V. K. MURTHY RAO The Association of Indian Automobile Manu-
SHRI S. P. RAO facturera, Bombay
WG Forge and Allied Industries Ltd, Thane SHRI B.K. &NANTHARAXIAH( Afturn&)
Nagarjuna Steels Ltd, Hyderabad SHRI ANANTHA REDDY SHRI J. SRINIVAS ( Alternntc )
REPRESENTATIVE REPRESENTATIVE SERI A. S. SA~ND
SHR~ B. S. SA~ND ( Alternate ) SHRI K. SHANRARANARAYANAN
Ministry of Defence ( DGI ) Automotive Research Association of India, Puns Saund Zweired Union (I) Ltd, Gwalior
Directorate General of Technical Development, New Delhi
SERI S. K. SHARMA I Ministry of Industrial Development SHRI T. R. SERQAL ( Alternate )
SHRI A. R. SONALKA~ Mahindra and Mahindra Ltd, Bombay SHRI A R. JANIKA ( Alternate )
SI~RI L. SRINIVASAYADHVAN Standard Motor Products of India Ltd. Madras SHRI K. RAN~ANATHAN ( Alternate )
SHRI M. S. GANAPATHY STJBRA- Mopeds ( India ) Ltd, Tirupathi MANIAM
SHRI A. G. NAMMALVAR ( Alternate ) SHRI S. TIWARI Directorate General Ordnance Factories, Calcutta
SHWI G. N. ROY ( Alternate ) SERI K. RA~HAVENDRAN, Director General, IS1 ( Ex-oficio Membrr )
Director ( Strut & Met )
Sccrctary
SHRI B. K. MUKHOPADEAYAY Assistant Director ( Metals ), IS1
( Continued on pag6 7 )
2
IS : 9175 ( Part 20 ) - 1986
Indian Standard RATIONALIZED STEELS FOR
THE AUTOMOBILE AND ANCILLARY INDUSTRY
PART 20 MECHANICAL AND PHYSICAL PROPERTIES OF
20MnCr5 GRADE STEEL
0. FOREWORD
0.1 This Indian Standard ( Part 20 )was adopted by the Indian Standards Institution on 27 March 1986, after the draft finalized by Co-ordinating Committee on Materials for Automobiles had been approved by Structural and Metals Division Council.
0.2 Part l* of this standard was published in 1979 which covers the chemical composition of 33 rationalized steels. The mechanical properties, hardenability and isothermal transformation characteristics of these 33 rationalized steels are being covered in different parts ofthis standard (Parts 2 to 34 ). The data concerning to these properties given in this standard is only for guidance and information purposks.
0.3 For the purpose of deciding whether a particular requirement of this standard is complied with, the final value, observed or calculated, expressing the result of a test or analysis, shall be rounded off in accord- ance with IS : 2-19607. The number of significant places retained in the rounded off value should be the same as that of the specified value in this standard.
1. SCOPE
1.1 This standaad ( Part 20 ) covers the mechanical properties, harden- ability and isothermal transformation characteristics of 20MnCr5 grade of steel for use by automobile and ancillary industry.
1.2 This is a carburizing ( case hardening ) steel used for components requiring high wear resistant surface, coupled with tough cores to resist shock loads and strength to give larger service life.
*Rationalized steels for the automobile and ancillary industry: Part 1 Chemical composition.
+Rules for rounding off numerical values ( reuiscd ).
3
IS : 9175 ( P8rt 20 ) - 1986
2. CHEMICAL COMPOSITION
2d,:o,he chemical composition of this grade of steel shall be as given
Constituents, prccnt
c Si Mn Cr S P
0.17-022 0.15-0.35 180- 140 1 oo- 1.30 0.035 Max 0035 Max
3. HARDNESS
3.1 The maximum hardness for this grade of steel delivered in the as rolled or annealed or normalized condition when determined in accord- ance with IS : 1500-1983* shall be 217 HBS.
4. MECHANICAL PROPERTIES
4.1 The mechanical properties of this grade of steel in the blank carburized and hardened condition when determined in accordance with IS : 1598.19771_ and IS : 1608-l 972: shall be as given in Table 1.
TABLE 1 MECHANICAL PROPERTIES IN BLANK CARBURIZED HARDENED CONDITION
LIMITING
BUILDING SECTION
mm
30
TENSILE STRENGTH
MPa
1 000-l 300
YIELD ELONGATION IZODIMPACTVALUE, STRESS GL 565sh Min, JOULES AT Roox Min Min TEMPERATURE MPa Percent
700 8 40
5. HOT WORKING AND HEAT-TREATMENT TEMPERATURES
5.1 The recommended hot working and heat-treatment temperatures are given below:
Forging/rolling 1 250C
Annealing/normalizing 860-910%
Carburising temperature 850.930C
Refining temperature 850-880%
Hardening temperature 8 lo-84OC
Tempering temperature 230C Max
*Method for Brine11 hardness test for metallic materials ( second reaision ). *Method for Izod impact test of metals ( jirst rsoision ). $Method for tensile testing of steel products ( jrst recision ).
4
IS t 9175 ( Part 26 ) - 1986
6. TRANSFORMATION CHARACTERISTICS
6.1 The isothermal transformation diagram for this grade of steel is gken in Fig. I.
AUSTENITISiNG TEMPERATURE 870% 10 Min. 1000
900
800
700
o, 600
o-1 1 10 102 103 104 105 sec. I 1 I I )
TIME - 1 10 100 1000 min
FIG. 1 ISOTHERMAL TRANSFORMATION DIAQR~ OF 20MnCr5 GRADE STEEL
5
IS x 9175 ( Part 26 ) - 1966
7. HARDENABILITY
7.1 The end quench hardenability curve is given in Fig. 2.
AUSTENITISING TEMPERATURE 87OrtSC 55
50
15
0 5 10 15 20 25 30 35 10 45 50 OISTANCE FROM THE QUENCHED EN0
FACE IN mm -_
Digtance 1 2345678 9 10 15 20 25 30 35 40 mn
Min(Rc) 41 40 39 37 36 34 33 31 31 29 25 23 21 - - -
Mux(Rc) 49 49 49 4a 48 47 46 45 44 43 40 37 35 34 33 31
FIG. 2 END QUENCH HARDENABILITY TEST DATA FOR 20MnCr5 GRADE STEEL
I8 : 9175 ( Part 29 ) - 1986
( Continued from popr 2 )
Panel to Collect Data on Steel for Automobile Purposes, SMDC 3l/P12
Conwean R+esmting
DR R. V. PATH9 Mahindra Ugine Steel Co Ltd, Khopoli
Members SHRI B. K. ANANTHARAYAIH WG Forge and Allied Industries Ltd, Thane
SHRI 0. B. DIN ( Altsrnatc ) PROF R. C. CFIATURVEDI Indian Institute of Technology, Bombay SHRI B. HARIDASACHAR Visvesvaraya Iron and Steel Ltd, Bhadravati
SHRI D. P. VERNEKAR ( Allcmats) SHRI H. A. JAISINOHANI Mahindra & Mahindra Ltd, Bombay SHRX M. G. LAWATE Tata Engineerin & Locomotive Co Ltd, Pune DR V. RAMABWAMY Research and 8 evelopment Centre for Iron and
Steel SAIL ( R & D Centre ), Ranchi SHRI S. R. MEDIRATTA ( Altcrnafe)
REPRESENTATIVE Automobile Products of India Ltd, Bombay DR K. R. SATYANARAYANAN College of Engineering, Pune
DR R. D. CHAUDRARI ( Alternate )
7
INTERNATIONAL SYSTEM OF UNITS ( SI UNITS )
Bmmc ullitm
QUANTITY
L-l@ Maas
Time
Electric current
Thermodynamic temperature
Luminous intensity
Amount of fiubstance
Supplementmy Uoltm
QUANTITY
Plane angle
Solid angle
Derived Unita
QUANTITY
Force
Energy
Power
Flux
Flux density
Frequency
Electric conductance
Electromotive force
Preasurc, rtress
UNIT
mctre
kilogram
second
ampere
kelvin
candela
mole
UNIT
radian
steradian
UNIT
newton
joule
watt
weber
teala
hertz
aiemens
volt
paacal
SYNBOL
m
kg !4
A
K
cd
mol
SYMBOL
rad
sr
SYMBOL
N
J w Wtl T
HZ
S
V
Pa
DE~~ITI~N
1 N = 1 kg.m/r
1 J=lNm
1 W = 1 J/s
1 Wb = 1 V.s
1 T = 1 Wb/m*
1 Hz = 1 c/s (s-l)
1 S = I A/V I V = 1 W/A
1 Pa = 1 N/m8
v: (Reaffirmed 2004)