Update: Stainless Steel
Mar 26, 2018
Update: Stainless Steel
Speaker Information
Shawn Chaney
Product Manager
Fort Wayne Metals Research Corp.
Stainless Steels for Medical Applications
More medical devices are made from stainless steel than
all other materials combined. Device designers select stainless for its ideal balance of strength, corrosion resistance, mechanical properties and cost. Applications include guide wires, catheters, staples, endoscopic devices, tools and a variety of coiled products. I will be discussing the various grades and tempers for medical coil winding applications. You will leave this session with an understanding of the material characteristics that result from the various melting methodologies, inclusion distribution and the resulting fatigue endurance limits.
Property Selection, What’s Important for the application?
formability
yield strength
ultimate tensile strength
ductility
biocorrosion
biocompatibility
crevice corrosion
corrosion potential
cost torqueability
steerability
straightness
dielectric strength
MRI compatibility
magnetic permeabilitysurface finish
toughnessnotch sensitivity
elongation
transformation temperature
permanent set
plateau strength
electrical resistance
emissivity
heat transfer
inclusion size
grain size
load type
stress intensity
stress corrosion cracking
pitting
weldability
cleanlinessFDA approval
ASTM specs
market acceptance radiopacity
wall thickness
safety factorsgalvanic corrosion
fatigue resistance
stress concentration
temperature property relationsresilience
residual stresses
hardness
Bending
What is Stainless Steel?
• Carbon steel does a great job in many applications. However, it has one major weakness, it rusts. Thus, the advent of stainless steel.
• Stainless Steel = Carbon steel + minimum of 10.5% Chromium
ASM Metals Handbook Desk Edition, Second Edition, pg 54
• Austenitic
• Martensitic
• Ferritic
• Duplex
• Precipitation Hardening
Stainless Steels
• Single best contributor to corrosion resistance
• Protective film forms when combined with oxygen, (passive oxide layer)
Chromium [Cr]
• Forms a passive oxide film layer; like chromium. Improves resistance to corrosion
• Primary element used to stabilize crystal structure of austenitic stainless
Nickel [Ni]
• Austenitic former in the 200 series
• Replaces nickel during shortages
• Does not aid in corrosion resistance
Manganese [Mn]
• 1% or more increases resistances to pitting & crevice corrosion, sulfuric, phosphoric, organic acids
• Increases strength at elevated temperatures
Molybdenum [Mo]
• Exists in all the stainless steels
• Detrimental effect when combined with chromium; susceptible to intergranular corrosion when in the temperature range of 425-815*C
Carbon [C]
• Added as carbide stabilizers in the austenitic grades; 8-10x’s carbon
• Added to 600 grades to promote precipitation hardening
Niobium [Nb]/Titanium
[Ti]/Tantalum [Ta]
• Amounts >1% improves resistance to oxidation and carburizationSilicon [Si]
• Improves resistance to oxidation and carburization
• Used to promote aging in PH grades (17-7PH)
Aluminum [Al]
• Added to austenitic grades to improve corrosion resistance to sulfuric acid. Reduces work hardening rate
• Used to promote aging in PH grades (17-4PH)
Copper [Cu]
• Effective austenitizing element, substituted for nickel. Influenced by carbon, chromium, nickel content.
• Improves mechanical properties of austenitic stainless at room & elevated temperatures
Nitrogen [N]
• Added to increase strength @ elevated temperaturesTungsten [W] & Vanadium [V]
• Added to improve machinability; chip formation
Sulfur [S], Selenium [Se], Phosphorus [P]
• Austenitic
• Martensitic
• Ferritic
• Duplex
• Precipitation Hardening
Stainless Steels
Austenitic Stainless SteelsAustenitic Grades – Chrome-Nickel
Alloy C Mn P S Si Cr Ni Mo OTHER
302 0.15 2 0.045 0.03 1 17.00/19.00 8.00/10.00
302B 0.15 2 0.045 0.03 2.00/3.00 17.00/19.00 8.00/10.00
303 0.15 2 0.2 0.15 1 17.00/19.00 8.00/10.00 0.6
303SE 0.15 2 0.2 0.06 1 17.00/19.00 8.00/10.00 Se 0.15 min.
304 0.08 2 0.045 0.03 1 18.00/20.00 8.00/10.50
304L 0.03 2 0.045 0.03 1 18.00/20.00 8.00/12.00
305 0.12 2 0.045 0.03 1 17.00/19.00 10.50/13.00
308 0.08 2 0.045 0.03 1 19.00/21.00 10.00/12.00
309 0.2 2 0.045 0.03 1 22.00/24.00 12.00/15.00
309S 0.08 2 0.045 0.03 1 22.00/24.00 12.00/15.00
310 0.25 2 0.045 0.03 1.5 24.00/26.00 19.00/22.00
310S 0.08 2 0.045 0.03 1.5 24.00/26.00 19.00/22.00
314 0.25 2 0.045 0.03 1.50/3.00 23.00/26.00 19.00/22.00
316 0.08 2 0.045 0.03 1 16.00/18.00 10.00/14.00 2.00/3.00
316L 0.03 2 0.045 0.03 1 16.00/18.00 10.00/14.00 2.00/3.00
317 0.08 2 0.045 0.03 1 18.00/20.00 11.00/15.00 3.00/4.00
321 0.08 2 0.045 0.03 1 17.00/19.00 9.00/12.00 Ti 5xC min.
347 0.08 2 0.045 0.03 1 17.00/19.00 9.00/12.00 Nb-Ta 10xC min.
348 0.08 2 0.045 0.03 1 17.00/19.00 9.00/13.00 Nb-Ta 10xC min./Ta 0.1,Co 0.2
384 0.08 2 0.015 0.03 1 15.00/17.00 17.00/19.00
385 0.03 2 0.015 0.03 1 11.50/13.50 14.00/16.00
All values are maximum unless stated in ranges
Austenitic Grades – Chrome-Nickel-Manganese-Nitrogen
Alloy C Mn P S Si Cr Ni N OTHER
201 0.15 5.50/7.50 0.06 0.03 1 16.00/18.00 3.50/5.50 0.25
202 0.15 7.50/10.00 0.06 0.03 1 17.00/19/00 4.00/6.00 0.25
205 0.12-0.25 14.0/15.5 0.06 0.03 1 16.00/18.00 1.0/1.75 0.32/0.40
216 0.08 7.5/9.0 0.045 0.03 1 17.5/22.0 5.0/7.0 0.25/0.50
216L 0.03 7.5/9.0 0.045 0.03 1 17.5/22.0 5.0/7.0 0.25/0.50
XM-1 0.08 5.0/6.5 0.04 0.18/0.35 1 16.0/18.0 5.0/6.5
XM-10 0.08 8.0/10.0 0.06 0.03 1 18.0/21.0 5.0/7.0 0.15/0.40
XM-11 0.04 8.0/10.0 0.06 0.03 1 18.0/21.0 5.0/7.0 0.15/0.40
XM-14 0.12 14.0/16.0 0.06 0.03 1 17.0/19.0 5.0/7.0 0.35/0.50
XM-19 0.06 4.0/6.0 0.04 0.03 1 20.5/23.5 5.0/6.0 0.20/0.40
XM-28 0.15 11.0/14.0 0.06 0.03 1 16.5/19.0 11.5/13.5 0.20/0.40
XM-29 0.08 11.5/14.5 0.06 0.03 1 17.0/19.0 2.50/3.75 0.20/0.40
XM-31 0.12 14.5/16.0 0.045 0.03 1 17.0/19.0 0.75 0.35
All values are maximum unless stated in ranges
Austenitic Stainless Steels
Martensitic Stainless Steels
All values are maximum unless stated in ranges
Martensitic Grades
C Mn P S Si Cr Ni Mo OTHER
403 0.15 1 0.04 0.03 0.5 11.50/13.00
410 0.15 1 0.04 0.03 1 11.50/13.50
414 0.12-0.25 1 0.04 0.03 1 11.50/13.50 1.25/2.50
416 0.08 1.25 0.06 0.15 1 12.00/14.00 0.6
416Se 0.03 1.25 0.06 0.06 1 12.00/14.00 Se 0.15 min
420 0.08 1 0.04 0.03 1 12.00/14.00
420F 0.08 1.25 0.06 0.15 1 12.00/14.00 0.6
422 0.04 1 0.025 0.025 0.75 11.00/13.00 0.50/1.00 0.75/1.25V 0.15/0.30
+W 0.75/1.25
431 0.12 1 0.04 0.03 1 15.00/17.00 1.25/2.50
440A 0.06 1 0.04 0.03 1 16.00/18.00 0.75
440B 0.15 1 0.04 0.03 1 16.00/18.00 0.75
440C 0.08 1 0.04 0.03 1 16.00/18.00 0.75
Ferritic Stainless Steels
All values are maximum unless stated in ranges
Ferritic Grades
C Mn P S Si Cr Ni Mo OTHER
405 0.08 1 0.04 0.03 1 11.50/14.50 Al-0.10/0.30
409 0.08 1 0.045 0.045 1 10.50/11.75 0.5 Ti 6xC 0.75
429 0.12 1 0.04 0.03 1 14.00/16.00
430 0.12 1 0.04 0.03 1 16.00/18.00 0.6
430F 0.12 1.25 0.06 0.15 1 16.00/18.00
430F Se 0.12 1.25 0.06 0.06 1 16.00/18.00 Se 0.15 min
434 0.12 1 0.04 0.03 1 16.00/18.00 0.75/1.25
436 0.12 1 0.04 0.03 1 16.00/18.00 0.75/1.25Nb-Ta 5xC min.
0.70 max
442 0.2 1 0.04 0.03 1 18.00/23.00
446 0.2 1.5 0.04 0.03 1 23.00/27.00 N 0.25 Max.
Precipitation Hardening Stainless Steels
All values are maximum unless stated in ranges
Precipitation Hardening (Semi-Austenitic)
Proprietary Name
C Mn Si Cr Ni Mo OTHER
17-7PH 0.09 1 1 17 7 1.0 AL
PH 15-7 Mo 0.09 1 1 15 7 2.2 1.2 Al
PH 14-8 Mo 0.05 0.1 0.1 15 8.5 2.5 1.1 Al
AM 350 0.08 0.8 0.25 16.5 4.3 2.75 0.1 N
AM 355 0.13 0.95 0.25 15.5 4.3 2.75 0.1 N
Precipitation Hardening (Austenitic)
Proprietary Name
C Mn Si Cr Ni Mo OTHER
A 286 0.08 1.4 0.4 15 26 1.3 0.3V,2.0Ti,0.35Al,0.003B
HNM 0.3 3.5 0.5 18.5 9.5 0 0.25 P
17-10P 0.1 0.6 0.5 17 11 0 0.3 P
Precipitation Hardening Stainless Steels
All values are maximum unless stated in ranges
Precipitation Hardening ( Martensitic)
Proprietary Name
C Mn Si Cr Ni Mo OTHER
Stainless W 0.06 0.55 0.6 16 7 1.0Ti,1.0Al,0.2N
17-4PH 0.07 1 1 17 4 4.0Cu,0.15/0.45Nb-Ta
PH 13-8 Mo 0.05 0.1 0.1 12.5 8 2.5 1.1 Al
Custom 450 0.03 0.25 0.25 15 6 0.8 1.5Cu,0.3NB
Custom 455 0.03 0.5 0.5 11.75 8.5 0.5 2.0Cu,1.2Ti,0.3Nb-Ta,0.005B
Pyromet X 15 0.03 0.1 0.1 12.5 8 2.9 20Co
AM 362 0.03 0.3 0.2 14.5 6.5 0.8Ti
AM 736 0.02 10 10 2 0.3 Al, 0.2Ti
15-5 PH 0.04 1 1 15 4.5 3.4 Cu, 0.25 Nb
ACF 77 0.15 0.3 0.25 14.5 10 5 13.5 Co, 0.5V
Melting Technology
• Primary Melting
– Electric Arc Furnace/Argon Oxygen Decarburization
• Secondary Remelting
– Vacuum Arc Remelting
Processing• Cold Working
– The process of increasing the dislocation density, thereby imparting an increase in strength, typically associated with a reduction in ductility
– CW 302 & 304 stainless becomes magnetic
• Heat Treating– Annealing - Restore ductility and reduce strength
– Stress relieving – Reduce stresses induced from cold working
– Age Hardening – Increase strength beyond the cold worked or annealed strength
(a)(b)
(c) (d) (e) (e)
Excerpt taken from ASTM F2754/2754M
Residual Stress• Mechanical Straightening
– Surface defects
– Discrete straight lengths
– The Bauschinger Effect• the phenomenon by which plastic deformation of a metal increases the yield
strength in the direction of plastic flow and decreases the yield strength in the opposite direction
• Thermal Stress Relieve– Surface defects
– Reduced mechanical properties
• FWM SLT® Wire
337342
331 332336
330
318
4542
40 38 33
31
38
300
310
320
330
340
350
360
370
380
390
400
0.39 0.59 0.64 0.74 0.89 1.11 1.28
13
.3%
incr
ease
12
.2%
incr
ease
12
.1%
incr
ease
11
.5%
incr
ease
9.8
% in
crea
se
9.4
% in
crea
se
11
.9%
incr
ease
Ultimate Tensile Strength (ksi)
Size(mm)
As DrawnHeat
TreatedIncrease
% Increase
0.39 337 382 45 13.3
0.59 342 384 42 12.2
0.64 331 371 40 12.1
0.74 332 370 38 11.5
0.89 336 369 33 9.8
1.11 330 361 31 9.4
1.28 318 356 38 11.9
Average: 332 370 38 11.5
302 / 304 Chemistry standards
• ASTM– A313 Standard Specification for Stainless Steel Spring
Wire• UNS 30200 (C - 0.12 max)• UNS 30400 (C - 0.08 max)
– F899 • UNS 30200 (C - 0.15 max)• UNS 30400 (C - 0.07 max)
• AISI– 302– 304
• JIS (Japanese Industrial Standards)
– JIS G 4308 Stainless Steel Wire Rods
– JIS G 4309 Stainless Steel Wires• 302 – not listed
• SUS 304 (C - 0.08 max)
– JIS G 4313 Cold Rolled Stainless Steel Strip for Springs
– JIS G 4314 Stainless Steel Wires for Springs• SUS302 (C – 0.15 max)
• SUS304 (C – 0.08 max)
302 / 304 Chemistry standards
• DIN Standards
– DIN 17440 Technical Delivery Conditions for Stainless Steel Drawn Wire
– EN 10088-1 Stainless Steels – Part 1 List of Stainless Steels
– DIN 17224 Stainless Steel Wire and Strip for Springs
– DIN 17443 Rolled and Wrought Stainless Steel Products for surgical implants
302 / 304 Chemistry standards
302 vs 304
• Primary difference is allowable Carbon levels
– 302 allows for a maximum of 0.12% C
– 304 allows for maximum of 0.08% C
– Note ASTM F899: 304 only allows 0.07% Carbon
• Thus any 304 will meet 302 requirement
• The original intent of 302 was a higher strength 300 series due to the higher carbon content, although today virtually everyone sells 304 as 302
Effect of Carbon on Austenitic Stainless Steels
Parameter Increasing Carbon Content
Cold Work rate, hardening factor Increases the work hardening rate
Intercrystalline corrosion Reduces the corrosion resistance
Sensitization Increases the likelihood of sensitization
ToughnessImproves toughness when forming or
shaping the wire
Cold Work304V 17-4 316LVM 475 455 465 470
%CW UTS, psi %CW4 UTS, psi %CW UTS, psi %CW UTS, psi %CW UTS, psi %CW UTS, psi %CW UTS, psi
0.0 110674 .0 148749 0.0 110000 0% 120,832 0% 163,082 0% 141,000 0% 110000
22.0 161748 32.9 162642 33.4 137315 15% 142,741 20% 170,513 15.4% 148,360 21% 146922
37.8 198978 46.6 167643 47.0 164047 33% 166,306 37% 180,984 33.4% 156,339 37% 161022
47.8 214752 57.8 176307 57.0 178530 46% 180,102 50% 186,544 45.8% 163,339 50% 173077
55.7 229109 66.5 182257 66.8 186686 58% 192,449 60% 194,146 58.0% 170,561 60% 186899
62.1 238679 73.4 190469 73.8 196473 67% 201,011 69% 198,943 66.4% 176,043 69% 194323
68.0 249455 78.9 201884 79.2 205251 73% 208,939 75% 208,116 73.8% 182,105 75% 201111
72.7 257098 83.3 206731 83.4 210584 79% 228,327 80% 215,381 79.2% 186,636 80% 211281
76.6 264503 86.7 212331 86.8 214937 83% 235,224 84% 226,955 83.4% 192,136 84% 221393
79.9 272172 89.5 222817 89.5 219249 87% 250,487 88% 234,453 86.8% 198,317 88% 230338
82.9 279805 91.7 232968 89% 246,559 90% 245,198 89.7% 204,651 90% 241463
85.1 283993 93.4 245325 92% 269,907 92% 261,996 91.8% 212,895 92% 256148
87.2 293698 94.8 257999 93% 271,707 94% 270,525 93.5% 217,166 94% 269948
89.2 299674 95.9 265961 95% 287,506 95% 281,192 94.5% 224,556 95% 285525
90.1 313039 96% 296,938 96% 301,389 95.9% 230,409 96% 299142
97% 310,906 96.8% 240,374
97% 315,988 97.4% 251,796
99% 349,166
99% 365,306
Stainless Cold Work Curves
000,000
050,000
100,000
150,000
200,000
250,000
300,000
350,000
400,000
450,000
0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100%
Custom 475 Custom 455 Custom 465 Custom 470 304V
Alloy 420 302V 17-4 316LVM
Property Selection, What’s Important for the application?
formability
yield strength
ultimate tensile strength
ductility
biocorrosion
biocompatibility
crevice corrosion
corrosion potential
cost torqueability
steerability
straightness
dielectric strength
MRI compatibility
magnetic permeabilitysurface finish
toughnessnotch sensitivity
elongation
transformation temperature
permanent set
plateau strength
electrical resistance
emissivity
heat transfer
inclusion size
grain size
load type
stress intensity
stress corrosion cracking
pitting
weldability
cleanlinessFDA approval
ASTM specs
market acceptance radiopacity
wall thickness
safety factorsgalvanic corrosion
fatigue resistance
stress concentration
temperature property relationsresilience
residual stresses
hardness
Bending
Inclusion Analysis
Divisions[microns]
Set A 302 Air Melt
[0.221 inches]
Set B304V Vacuum
Remelt[0.250 inches]
< 1.0 1838 677
1.0 to 1.9 132 73
2.0 to 2.9 34 22
3.0 to 3.9 9 9
4.0 to 4.9 1 4
5.0 to 5.9 1 2
6.0 to 6.9 0 0
7.0 to 7.9 1 0
8.0 to 8.9 0 0
9.0 to 9.9 0 0
10.0 to 10.9 0 1
11.0 to 11.9 0 0
12.0 to 12.9 0 0
13.0 to 13.9 0 0
14.0 to 14.9 0 0
> / = 15.0 0 0
Total Count 2022 788
Percentage of Area Examined
0.0256 0.0154
0
500
1000
1500
2000
2500
2022
788
302 Air Melt 304V Vacuum Remelt
Property Selection, What’s Important for the application?
formability
yield strength
ultimate tensile strength
ductility
biocorrosion
biocompatibility
crevice corrosion
corrosion potential
cost torqueability
steerability
straightness
dielectric strength
MRI compatibility
magnetic permeabilitysurface finish
toughnessnotch sensitivity
elongation
transformation temperature
permanent set
plateau strength
electrical resistance
emissivity
heat transfer
inclusion size
grain size
load type
stress intensity
stress corrosion cracking
pitting
weldability
cleanlinessFDA approval
ASTM specs
market acceptance radiopacity
wall thickness
safety factorsgalvanic corrosion
fatigue resistance
stress concentration
temperature property relationsresilience
residual stresses
hardness
Bending
Surface Finish
Polycrystalline Drawn
Diamond Drawn
Property Selection, What’s Important for the application?
formability
yield strength
ultimate tensile strength
ductility
biocorrosion
biocompatibility
crevice corrosion
corrosion potential
cost torqueability
steerability
straightness
dielectric strength
MRI compatibility
magnetic permeabilitysurface finish
toughnessnotch sensitivity
elongation
transformation temperature
permanent set
plateau strength
electrical resistance
emissivity
heat transfer
inclusion size
grain size
load type
stress intensity
stress corrosion cracking
pitting
weldability
cleanlinessFDA approval
ASTM specs
market acceptance radiopacity
wall thickness
safety factorsgalvanic corrosion
fatigue resistance
stress concentration
temperature property relationsresilience
residual stresses
hardness
Bending
0
0.5
1
1.5
2
2.5
3
3.5
0
50,000
100,000
150,000
200,000
250,000
300,000
350,000
302 304V 316-LVM 420 455 470Average Yield Strength (psi) Average Ultimate Tensile Strength (psi) Average Elongation (%)
Property Selection, What’s Important for the application?
formability
yield strength
ultimate tensile strength
ductility
biocorrosion
biocompatibility
crevice corrosion
corrosion potential
cost torqueability
steerability
straightness
dielectric strength
MRI compatibility
magnetic permeabilitysurface finish
toughnessnotch sensitivity
elongation
transformation temperature
permanent set
plateau strength
electrical resistance
emissivity
heat transfer
inclusion size
grain size
load type
stress intensity
stress corrosion cracking
pitting
weldability
cleanlinessFDA approval
ASTM specs
market acceptance radiopacity
wall thickness
safety factorsgalvanic corrosion
fatigue resistance
stress concentration
temperature property relationsresilience
residual stresses
hardness
Bending
200
250
300
350
400
450
500
550Attained Hardness - HVN
25
30
35
40
45
50
55
Converted Hardness - HRC
Property Selection, What’s Important for the application?
formability
yield strength
ultimate tensile strength
ductility
biocorrosion
biocompatibility
crevice corrosion
corrosion potential
cost torqueability
steerability
straightness
dielectric strength
MRI compatibility
magnetic permeabilitysurface finish
toughnessnotch sensitivity
elongation
transformation temperature
permanent set
plateau strength
electrical resistance
emissivity
heat transfer
inclusion size
grain size
load type
stress intensity
stress corrosion cracking
pitting
weldability
cleanlinessFDA approval
ASTM specs
market acceptance radiopacity
wall thickness
safety factorsgalvanic corrosion
fatigue resistance
stress concentration
temperature property relationsresilience
residual stresses
hardness
Bending
Bend Moment Test System
• Acculine Model AE3BM
• Max Load: 10 lbf
• Max Torque: 12 lbf-in
• Max Rotation: 15°/sec
• Max Moment Arm: 1.5 cm
0
2
4
6
8
10
12
14
Yield Moment (N·cm)
0
2
4
6
8
10
12
14
16
18
Ultimate Moment (N·cm)
0.0
0.2
0.4
0.6
0.8
1.0
1.2
1.4
Stiffness
0
1
2
3
4
5
6
7
8
9
10
Cycles to Failure
Property Selection, What’s Important for the application?
formability
yield strength
ultimate tensile strength
ductility
biocorrosion
biocompatibility
crevice corrosion
corrosion potential
cost torqueability
steerability
straightness
dielectric strength
MRI compatibility
magnetic permeabilitysurface finish
toughnessnotch sensitivity
elongation
transformation temperature
permanent set
plateau strength
electrical resistance
emissivity
heat transfer
inclusion size
grain size
load type
stress intensity
stress corrosion cracking
pitting
weldability
cleanlinessFDA approval
ASTM specs
market acceptance radiopacity
wall thickness
safety factorsgalvanic corrosion
fatigue resistance
stress concentration
temperature property relationsresilience
residual stresses
hardness
Bending
• Instron Model 55MT1
• Max Torque: 22 N-m (200 lbf-in)
• Max Axial Load: 100 lbf
• Test Speed Range: 0-120 rpm
• Max Gage Length: 18 in. (depending on clamping device)
• Rotation: Clockwise & Counterclockwise
• Two Configurations:
– Floating Stage – constant axial load via dead weights
– Fixed Stage – monitored axial load increase via load cell
Torsion Testing
0
2
4
6
8
10
12
14
16
18
20Ultimate Torque (in·oz)
0
10
20
30
40
50
60
70
80
90
Revolutions to Fracture
Property Selection, What’s Important for the application?
formability
yield strength
ultimate tensile strength
ductility
biocorrosion
biocompatibility
crevice corrosion
corrosion potential
cost torqueability
steerability
straightness
dielectric strength
MRI compatibility
magnetic permeabilitysurface finish
toughnessnotch sensitivity
elongation
transformation temperature
permanent set
plateau strength
electrical resistance
emissivity
heat transfer
inclusion size
grain size
load type
stress intensity
stress corrosion cracking
pitting
weldability
cleanlinessFDA approval
ASTM specs
market acceptance radiopacity
wall thickness
safety factorsgalvanic corrosion
fatigue resistance
stress concentration
temperature property relationsresilience
residual stresses
hardness
Cyclic Polarization Corrosion
• Accelerated Corrosion
• Determination of the material’s pitting, or breakdown potential
• Phosphate Buffered Saline Solution (8-9% NaCl) @ 37°C
Cyclic Polarization Corrosion
Property Selection, What’s Important for the application?
formability
yield strength
ultimate tensile strength
ductility
biocorrosion
biocompatibility
crevice corrosion
corrosion potential
cost torqueability
steerability
straightness
dielectric strength
MRI compatibility
magnetic permeabilitysurface finish
toughnessnotch sensitivity
elongation
transformation temperature
permanent set
plateau strength
electrical resistance
emissivity
heat transfer
inclusion size
grain size
load type
stress intensity
stress corrosion cracking
pitting
weldability
cleanlinessFDA approval
ASTM specs
market acceptance radiopacity
wall thickness
safety factorsgalvanic corrosion
fatigue resistance
stress concentration
temperature property relationsresilience
residual stresses
hardness
Rotary Beam Fatigue
• ASTM E2948: Conducting Rotating Bending Fatigue Tests of Solid Round Fine Wire
• Environment• RO Water, Saline, Phosphate Buffered Saline• ~10°C to 50°C• 37°C (Body Temperature) Most Common
• Fiber Optic Fracture Detection System– Developed for coated wire/cable testing
Wire Supports
Incoming Solution Return
Shutoff Wire
Thermocouple
Rotary Beam Fatigue
Rotary Beam Fatigue
Fatigue Performance
0
50
100
150
200
250
300
1,000 100,000 10,000,000
304V 304V Hyten 316LVM
Reminders for Wednesday October 21st
Remember to visit the Exhibit Hall!Located in Hall C
10:30 AM – 5:00 PM
The Metal Engineering Expo Evening Event at theNASCAR Hall of Fame
Located at the NASCAR Hall of Fame 6:30 PM – 9:30 PM(Tickets Required)