Update: Stainless Steel - SMI Metal Engineering · PDF fileUpdate: Stainless Steel. Speaker...

Update: Stainless Steel

Speaker Information

Shawn Chaney

Product Manager

Fort Wayne Metals Research Corp.

[email protected]

mailto:[email protected]

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


Austenitic Stainless Steels

Martensitic Stainless Steels


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


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


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


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


Precipitation Hardening ( Martensitic)

Proprietary Name


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)


• 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 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


formability

yield strength


ductility

biocorrosion

biocompatibility

crevice corrosion

corrosion potential

cost torqueability

steerability

straightness

dielectric strength

MRI compatibility



elongation


permanent set

plateau strength


emissivity

heat transfer

inclusion size

grain size

load type

stress intensity


pitting

weldability


ASTM specs


wall thickness


fatigue resistance



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


formability

yield strength


ductility

biocorrosion

biocompatibility

crevice corrosion

corrosion potential

cost torqueability

steerability

straightness

dielectric strength

MRI compatibility



elongation


permanent set

plateau strength


emissivity

heat transfer

inclusion size

grain size

load type

stress intensity


pitting

weldability


ASTM specs


wall thickness


fatigue resistance



residual stresses

hardness

Bending

Surface Finish

Polycrystalline Drawn

Diamond Drawn


formability

yield strength


ductility

biocorrosion

biocompatibility

crevice corrosion

corrosion potential

cost torqueability

steerability

straightness

dielectric strength

MRI compatibility



elongation


permanent set

plateau strength


emissivity

heat transfer

inclusion size

grain size

load type

stress intensity


pitting

weldability


ASTM specs


wall thickness


fatigue resistance



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 (%)


formability

yield strength


ductility

biocorrosion

biocompatibility

crevice corrosion

corrosion potential

cost torqueability

steerability

straightness

dielectric strength

MRI compatibility



elongation


permanent set

plateau strength


emissivity

heat transfer

inclusion size

grain size

load type

stress intensity


pitting

weldability


ASTM specs


wall thickness


fatigue resistance



residual stresses

hardness

Bending

200

250

300

350

400

450

500

550Attained Hardness - HVN

25

30

35

40

45

50

55

Converted Hardness - HRC


formability

yield strength


ductility

biocorrosion

biocompatibility

crevice corrosion

corrosion potential

cost torqueability

steerability

straightness

dielectric strength

MRI compatibility



elongation


permanent set

plateau strength


emissivity

heat transfer

inclusion size

grain size

load type

stress intensity


pitting

weldability


ASTM specs


wall thickness


fatigue resistance



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


formability

yield strength


ductility

biocorrosion

biocompatibility

crevice corrosion

corrosion potential

cost torqueability

steerability

straightness

dielectric strength

MRI compatibility



elongation


permanent set

plateau strength


emissivity

heat transfer

inclusion size

grain size

load type

stress intensity


pitting

weldability


ASTM specs


wall thickness


fatigue resistance



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


formability

yield strength


ductility

biocorrosion

biocompatibility

crevice corrosion

corrosion potential

cost torqueability

steerability

straightness

dielectric strength

MRI compatibility



elongation


permanent set

plateau strength


emissivity

heat transfer

inclusion size

grain size

load type

stress intensity


pitting

weldability


ASTM specs


wall thickness


fatigue resistance



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


formability

yield strength


ductility

biocorrosion

biocompatibility

crevice corrosion

corrosion potential

cost torqueability

steerability

straightness

dielectric strength

MRI compatibility



elongation


permanent set

plateau strength


emissivity

heat transfer

inclusion size

grain size

load type

stress intensity


pitting

weldability


ASTM specs


wall thickness


fatigue resistance



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)

Update: Stainless Steel - SMI Metal Engineering · PDF fileUpdate: Stainless Steel. Speaker...

Documents

Transcript of Update: Stainless Steel - SMI Metal Engineering · PDF fileUpdate: Stainless Steel. Speaker...