含铋不锈钢的热变形行为

Thermal deformation behavior on stainless steel containing bismuth

针对含铋不锈钢材料在热加工过程中容易产生裂纹的问题,对其进行了热压缩实验,得到了含铋不锈钢材料的真实应力-真实应变曲线,并考虑到热塑性变形以及试样与刀具摩擦引起的试样温度和应力变化,对真实应力-真实应变曲线进行了修正,消除了热塑性变形和摩擦引起的实验误差。并基于动态材料模型(DMM)和Murty准则,建立了易切削奥氏体不锈钢热加工图,给出了易切削奥氏体不锈钢热加工的稳定区域和不稳定区域,选择稳定区域的工艺参数进行现场轧制,轧制实验表明,在所选稳定区条件下,轧制件截面未产生裂纹。

Aiming at the problem that stainless steel materials containing bismuth are prone to cracks during the thermal processing,thermal compression experiments were carried out to obtain the true stress-true strain curves of stainless steel materials containing bismuth.Considering the thermoplastic deformation and the temperature and stress changes of sample caused by the friction between sample and tool,the true stress-true strain curve was corrected to eliminate the experimental errors caused by thermoplastic deformation and friction.Furthermore,based on the dynamic material model(DMM)and Murty criterion,a thermal processing map of free-cutting austenitic stainless steel was established,and the stable and unstable areas of thermal processing for free-cutting austenitic stainless steel were given.The process parameters for the stable area were selected for on-site rolling.The rolling experiment shows that under the selected stable area conditions,no cracks occur in the cross section of the rolled piece.