Cr-Ni 系オーステナイトステンレス鋼の塑性変形に及ぼす積層欠陥エネルギーの影響

概要

論文の詳細を見る
A series of Cr-Ni austenitic stainless steels whose stacking fault energy (SFE) was varied systematically, were deformed by tension at the condition of temperature, 291 and 473K, and strain rate range from 10^<-5> to 10^<-3>s^<-1>. The various plastic flow parameters such as strain hardening exponent, COTTRELL-STOKES ratio, activation volume and etc., were determined through usual tensile test and temperature or strain rate change tests. The measurement of magnetic permeability was also carried out continuously during the tensile test in order to check the occurrence of stress induced martensite. Although the dependence of SFE on yield stress was not so clear at room temperature (291K), ultimate tensile stress (UTS) and the strain hardening exponent apparently depended upon SFE, namely, both the UTS and the strain hardening exponent decreased with increasing SFE. The COTTRELL-STOKES ratio determined by the temperature change tests was an appropriate measure to check the relative contribution of thermal and athermal components of flow stress. According to the linear increase of the ratio with SFE, it was clarified that the higher the SFE, the larger became the contribution ratio of the athermal component. The activation volume measured by the strain rate change tests, decreased with increasing SFE, and the degree of its variation with strain was larger for higher SFE steels.
社団法人日本鉄鋼協会の論文
1985-04-01