오스테나이트계 Fe-Cr-C-Mn계 합금에서 변형유기 ε/α` 마르텐사이트 상변태 거동 및 sliding wear 손사앙 거동에 미치는 온도의 영향

Abstract

Strain-induced martensitic transformation was utilized for improving the sliding wear resistance in austenitic Fe-based alloys because it was expected that the strain-induced martensitic transformation might absorb the energy by external stress and decrease the adhesion tendency due to increasing hardness. Thus, for this thesis, the effects of temperature on the strain-induced ε/α’ martensitic transformation behavior and the correlation between this behavior and sliding wear in Fe-12Cr-0.4C-xMn (x = 5, 10, and 20 wt.%) alloys were investigated. First, to evaluate the effects of temperature on the strain-induced ε/α’-martensitic transformation behavior, the investigation was divided into the following sections: (1) measurement of stacking fault energy (SFE) at various temperatures, (2) investigation of the behavior of strain-induced α’-martensitic transformation at various temperatures. Results showed that both SFE increased with increasing temperature. When the temperature increased, the γ→ε and γ→α’ martensitic transformation was suppressed. Next, sliding wear tests of Fe-12Cr-0.4C-xMn (x = 5, 10 and 20 wt.%) alloys at various temperatures were performed. Results showed that, with increasing temperatures, the sliding wear resistance increased with decreasing SFE due to the formation of strain-induced martensite. The γ→ε strain-induced martensitic transformation is considered to be more beneficial to the high temperature wear resistance of Fe-Cr-C-Mn alloys than the γ→α` strain-induced martensitic transformation In this study, it seemed the strain-induced martensitic transformation affected sliding wear resistance through two effects. One is the absorption energy by the strain-induced martensitic transformation and the other is that the adhesion tendency decreased due to increasing hardness.