Steels_ Metallurgy and Applications, Third Edition

Stainless steels 349

1800

1600 304 \

302

~ 1400 316

~- 1200 30g

310 \

1000 - X~X~ ' \

309 ~['~ 309 1304

600 ",~ ~ ..... ~",,- 1321

.... _ 310 '\ ~[i"~ 310 ~ ~316

"- , "~~~"~,

400-3,6......N L347

200

,I ..... I i I ......... 1,, , I

80

,r

to r

to .-. 60

r o

..g r^40

u.I

20

• i
  /
  /


• 316, / ~,,..Z r'302 1304
  309 ~. ...^1316 (321
  310


• J 1347
  304' 13o9
  1.310

I _ J _ I I 1 I

-200 0 200 400 600 800

Temperature (~

Figure 4.32 Tensile properties of standard austenitic stainless steels: -200 to 800"C
(After Sanderson and Llewellyn 3~

Types 309 (25% Cr, 15% Ni) and 310 (25% Cr, 20% Ni), possess the highest
strengths. However, at temperatures below 100~ deformation in the tensile test
takes place by means of:

1. Slip/dislocation movement.


2. Transformation to strain-induced martensite.

Thus the more lowly alloyed grades such as Type 304 (18% Cr, 9% Ni)
undergo strain-induced transformation to martensite with relatively little strain