準安定オーステナイト系ステンレス鋼の強度・延性に及ぼす残留オーステナイトの影響
1997 年 83 巻 5 号 p. 341-346
詳細
1997 年 83 巻 5 号 p. 341-346
Effect of retained austenite on strength and ductility has been investigated in cold rolled metastable austenitic stainless steels having various austenite stabilities. Steels consist of from 50 to 60vol% martensite through 50% cold rolling at several temperatures. The steels achieved high strength by aging at 400°C for 3.6ks after 50% cold rolling. A stabilization of austenite generally enhanced the 0.2% proof stress and tensile strength. An increase in the strength results from dislocation morphology of cold rolled austenite and this is attributable mainly to planar dislocation of the austenite. In Erichness test, maximum ductility is obtained in steel with austenite stability Md(N) (= 580-520C-2Si-16Mn-16Cr-23Ni-300Ni-26Cu) of 40. Good ductility is a consequence of the formation of strain induced martensite during deformation. It is concluded that optimum austenite stability Md(N) is 40 to obtain high strength and ductility.
