安定オーステナイト系ステンレス鋼の加工硬化と変形組織に及ぼす炭素および窒素の影響

摘要

Stable austenitic stainless steels containing 0.1 % carbon and nitrogen (Fe-18%Cr-12%Ni-0.1%C and Fe-18%Cr-12%Ni-0.1 %N alloys) were tensile-tested to clarify the difference between the effects of carbon and nitrogen on the work hardening behavior as well as the deformation microstructure development in austenite. The carbon-added steel exhibited a much larger work hardening rate than the nitrogen-added steel in the high strain region (true strain > 0.25) although the dislocation accumulation was more significant in the nitrogen-added steel. EBSD analysis revealed that deformation twins were more frequently formed in the carbon-added steel, which leads to the TWIP effect. The reason why the nitrogen-added steel showed the less twinning behavior seemed to be mainly related with the short range order (SRO) composed of Cr and N atoms.%オーステナイト系ステンレス鋼の加工硬化に関しては，その加工性や強度特性の観点からこれまでに数多くの研究がなされてきた。例えばSUS304やSUS301などの準安定オーステナイト系ステンレス鋼では，加工誘起マルテンサイト変態に起因した著しい加工硬化が生じ，大きな均一伸びが得られることはTRIP効果としてよく知られた事実となっている。