氮含量对0Cr16Ni5Mo马氏体不锈钢高温热变形行为影响

Effect of nitrogen content on the hot deformation behavior of 0Cr16Ni5Mo martensitic stainless steel

采用Gleeble3800试验机对三种不同N含量的0Cr16Ni5Mo马氏体不锈钢进行等温热压缩实验.通过对真应变-应力曲线及压缩后变形组织的观察,发现相同热变形条件下,N含量的增加提高了试验钢的流变应力,抑制了再结晶晶粒长大.采用Zener-Hollomon参数,以流变应力方程为基础,构建三种本构模型.通过观察拟合应力值与实验值的离散性,确定双曲正弦模型更适用于本试验钢的本构方程计算,优化此计算模型,获得了三种试验钢的本构方程.

The hot deformation behavior of 0 Cr16 Ni5 Mo martensitic stainless steel with different nitrogen contents was studied on a Gleeble3800 thermal machine. The true strain-stress curves and deformed microstructures of the tested steels were investigated. The result shows that with an increase in nitrogen content,the stress increases and the recrystallized grain size reduces. Using the flow stress equation combined with Zener-Hollomon parameters,three constitutive equation models were established. Comparing the stress values from the constitutive equation models and the experiment,the hyperbolic sine model performed best. So,the constitutive equations for the tested steels were obtained by using the hyperbolic sine mode,with some improvements made during the calculation.