采用纳米探针研究了TRIP1000钢中不同组织的纳米压痕硬度及变形行为。结果表明:热处理后该钢的显微组织由铁素体、贝氏体和残余奥氏体组成;贝氏体比铁素体和奥氏体开始屈服变形时的纳米硬度值高,承受的最大载荷约是铁素体和奥氏体的两倍;铁素体在屈服变形时的柯氏气团效应和不稳定的奥氏体在屈服变形时的应力松弛是造成TRIP1000钢屈服失稳的主要原因;稳定的奥氏体在应力松弛前发生了大量塑性变形,屈服失稳时的应变量处于宏观拉伸曲线的应变硬化阶段。
Nano-indentation hardness and deformation behavior of the microstructure in the TRIP1000 steel were studied by nano probe experiment. The results show that the microstructure of the steel was mainly composed of ferrite, bainite and residual austenite after heat treatment. The bainite had higher nano hardness at the beginning of yield deformation and twice maximum load bearing as much as the ferrite and austenite. The main reasons on yield deformation destabilization of the TRIP1000 steel were Cottrel latmosphere effect of ferrite and stress relaxation of astable austenite during yield deformation. Stable austenite took place a lot of plastic deformation before stress relaxation and the strain was in strain hardening processing of the macro tensile curves during yield deformation destabilization.