控氮304不锈钢热变形过程中的动态再结晶行为研究  

Dynamic Recrystallization Behavior of Nitrogen-Controlled 304 Stainless Steel in Hot Deformation

作　　者：任伟 吴冰洁 邱阳[2] 王晓童 李梅娥 REN Wei;WU Bingjie;QIU Yang;WANG Xiaotong;LI Mei’e(State Key Laboratory for Mechanical Behavior of Materials, Xi’an Jiaotong University, Xi’an 710049, China;Key Lab of Nuclear Reactor System Design Technology, Nuclear Power Institute of China, Chengdu 610200, China)

机构地区：[1]西安交通大学金属材料强度国家重点实验室,西安710049 [2]中国核动力研究设计院核反应堆系统设计技术重点实验室,成都610200

出　　处：《西安交通大学学报》2021年第3期145-154,共10页Journal of Xi'an Jiaotong University

摘　　要：为优化控氮304不锈钢热成型的工艺,深入分析了其在热变形过程中的动态再结晶行为并建立了完整的数学模型。通过热压缩实验获得了16组不同温度、不同应变速率下的流动应力曲线,采用二次求导法确定了发生动态再结晶的临界应力σc、饱和应力σs、稳态应力σss等特征值,结合相应的显微组织分析表明:随着变形温度的升高、应变速率的减小,动态再结晶易发生。基于Estrin-Mecking位错密度演化方程及Avrami动力学方程,建立了该材料的热变形流动应力模型及动态再结晶动力学模型,模型预测的流动应力曲线与实验结果吻合较好,动力学模型预测的动态再结晶分数曲线也与实验观察到的晶粒组织变化趋势一致,证明了该数学模型的有效性。To adjust the dynamic recrystallization related parameters for the hot rolling process of nitrogen-controlled 304 stainless steel,the material was subjected to hot compression experiments at different temperatures and strain rates.The results showed that as the temperature increases and the strain rate decreases,the dynamic recrystallization behavior is more likely to occur.The critical stressσc,saturation stressσs,steady-state stressσss and other characteristic values for dynamic recrystallization are determined by the second derivative of the stress-strain curve.Based on this parameters,the dislocation density evolution equation and Avrami kinetic equation are introduced,and the thermal deformation flow stress model and dynamic recrystallization kinetic model of the material are established.The calculated values of the hot deformation flow stress model are in good agreement with the experimental values.The dynamic recrystallization fraction curve obtained by kinetics model is consistent with the change trend of the grain structure observed in the experiment.

关 键 词：控氮304不锈钢 动态再结晶 流动应力模型 Avrami动力学方程 

分 类 号：TG111.7[金属学及工艺—物理冶金]