热加工工艺对316LN奥氏体不锈钢晶粒度的影响研究

Effect of hot working process on the grain size of 316LN austenitic stainless steels

采用Zeiss Imager金相显微镜观察316LN奥氏体不锈钢微观组织形貌,研究了变形温度、变形率以及固溶温度对其晶粒度的影响。结果表明,随着变形温度和变形率的增加,显著促进了其动态再结晶的发生,有助于获得细化和均匀化的奥氏体不锈钢晶粒。锻造变形后钢板的晶粒度由小到大依次为表面>1/4处>心部,变形温度和变形量分别为1050℃,30%时,变形后的晶粒度可达到6级左右。固溶处理对锻造后的钢板晶粒度控制具有均质化作用,结合Jmat-Pro计算分析固溶处理结果,固溶温度应控制在1020~1040℃范围内,温度过高容易导致晶粒过度长大,温度过低容易导致Cr2N相析出,影响钢板的塑性和耐蚀性能。

The grain morphologies in 316LN austenitic stainless steel were observed by Zaiss Imager metallographic microscope.The effects of deformation temperatures,deformation rates and solution temperatures on the grain size of 316LN steel were systematically studied.The experimental results show that the dynamic recrystallization(DRX)easily occurs with the increasing deformation temperatures and deformation rates,which is helpful for the grain refinement in 316LN steel.The orders of grain size at different position of forged sample from large to small after forging are the core,1/4 diameter,and the surface.The grain size after deformation can reach about grade 6 when the deformation is 30%at 1050℃.The solution treatment has a positive effect on the grain homogenization.According to the Jmat-Pro calculation and solution treatment results,too high temperature will cause the grains coarsening,while too low temperature can easily lead to precipitation of Cr2N,which affects the plasticity and corrosion resistance of the steels.The solution treatment temperature should be controlled at 1020~1040℃.