準安定16-10ステンレス鋼の結晶粒超微細化による強化
1988 年 74 巻 6 号 p. 1058-1064
詳細
1988 年 74 巻 6 号 p. 1058-1064
The behavior of reversion from deformation induced martensite to austenite and the mechanical properties of specimens containing reversed austenite were investigated using a 15.6%Cr-9.8%Ni steel by means of transmission electron microscopy, magnetic analysis and tensile testing. Martensite content of specimens was controlled by cold rolling, and salt bath was used for reversion treatment. The results are as follows :
(1) In case of 0.6ks isochronic annealing, martensite content of specimens decreases abruptly in the temperature range from 800K to 900K as the result of reversion to austenite and the temperature range where reversion occurs is not affected by the cold working before annealing.
(2) The 0.2% proof stress of specimens containing work hardened austenite and reversed austenite is dependent on the volume fraction and the strength of each phase.
(3) Additional cold rolling of deformation induced martensite is very effective for grain refining of reversed austenite formed by the following 873K-0.6ks annealing, resulting in increase of 0.2% proof stress. A specimen, for example, with 93% cold rolling prior to the reversion treatment has an ultra fine austenitic structure with the mean grain size of 0.5lm giving a high 0.2% proof stress of about 0.7GPa.
