오스테나이트계 스테인리스강의 변형저항과 고온 유동응력의 예측

초록

The equation for predicting deformation resistance and flow stress of austenitic stainless steels were investigated by means of hot torsion tests. The torsion tests were carried out in the temperature ranges 900 - 1100℃ and the strain rate ranges 0.05 - 5 /s to study the high temperature softening behavior. Dynamic recrystallization(DRX) which plays a major role for reducing the flow stress was described by modifying Avrami’s equation. For the exact prediction of flow stress, the effective stress-effective strain curves were divided into two regions, the DRV(dynamic recovery)region and the DRX(dynamic recrystallization) region. The flow stress could be expressed as a function of strain along with the Zener-Hollomon parameter. It was found that the calculated flow stress of the alloy was in good agreement with that of the observed flow stress