극저온용 스테인레스 강의 저온거동 특성

Abstract

Austenitic stainless steels(SUS 304, SUS 316), which are used for safety control valve of LNG carrier, are occasionally exposed in the cryogenic environment. In this regards, it is required to evaluate the mechanical charact eristics under the low temperature environment. In this study, a series of uniaxial tensile test was carried out varying temperature for austenitic stainless steel. The phenomena of the strain-induced plasticity have been observed on the all tempera ture ranges. The critical value for threshold of 2nd hardening due to the phase transformation induced plasticity as well as the increase of hardening have been reported. The summarized experimental results would be used for the validation of numerical techniques applicable for the nonlinear hardening behavior of austenitic stainless steel under the cryogenic temperature environment. ※Keywords: Austenitic stainless steel(오스테나이트계 스테인레스강), Cryogenic environment (극 저온 환경), Tensile test(인장실험), Mechanical behavior(기계적 거동), Phase transformation induced plasticity(변태소성), 임계변형율(Threshold strain)