超纯Cr17铁素体不锈钢热变形过程的动态回复行为

Dynamic Recovery Behavior in Hot Deformation of Ultra-purified Cr17 Ferritic Stainless Steel

采用热力模拟试验机进行单道次压缩试验,旨在揭示超纯Cr17铁素体不锈钢在热变形过程中的动态回复行为.在变形速率为1 s-1,最大真应变为0.8的条件下研究了900~1 150℃范围内的热变形行为及组织演化规律.结果表明,单道次压缩得到的应力-应变曲线均呈动态回复型.变形温度越高,动态回复越快.当变形温度较低时,微观组织演化以晶界拱出和变形晶粒的形成为主要特征;当变形温度较高时,微观组织演化以大量亚晶界和亚晶的形成为主要特征.

Using a thermomechanical simulator,single-pass compression tests were carried out to clarify the dynamic recovery behavior in the hot deformation process of ultra-purified Cr17 ferritic stainless steel.The microstructure evolution during hot deformation was investigated at 900～1 150 ℃ with the maximum true strain of 0.8 and strain rate of 1 s-1.The results show that the stress-strain curves of single-pass compression are all characterized by dynamic recovery.As deformation temperature increases,the dynamic recovery occurs much faster. When the compression is performed at low temperature,deformed grains are formed and bulging of initial grain boundary occurs.While,at high temperature,the microstructure evolution will be characterized with the formation of a large quantity of sub-grain boundaries and sub-grains.