Ti微合金化汽车大梁钢510L动态再结晶行为

采用单道次压缩实验和阶梯试样热轧-淬火实验研究了低成本的Ti微合金化汽车大梁钢510L的动态再结晶行为.结果表明，应变速率为0.1s^-1时，变形温度为850~1050℃时均发生动态再结晶，应变速率为0.2s^-1时，只有在变形温度高于950℃时发生动态再结晶.变形温度的升高和变形量的增大会逐渐细化奥氏体晶粒，并使再结晶体积分数趋于增大.回归得到实验钢的动态再结晶激活能仅为211.43kJ/mol，说明Ti的添加几乎没有抑制高温奥氏体的动态再结晶，并建立了动态再结晶临界应变模型和动力学模型.

Dynamic Recrystallization Behaviors of Ti Micro-alloyed 510L Steel for Automobile Frame

The dynamic recrystallization behaviors of Ti micro-alloyed 510L steel for automobile frame were investigated using single-pass compression tests and hot-rolling and quenching tests for step samples. The results show that when the strain rate is 0.1s^-1， the dynamic recrystallization can occur at the deformation temperature ranging from 850 to 1050℃; while， when the strain rate is 0.2s^-1， it only occurs at the temperature above 950℃.With increasing the deformation temperature and strain， the average grain size of the austenite decreases and the volume fraction of recrystallization increases. By regression analysis， the activation energy for dynamic recrystallization in the tested samples is 211.43kJ/mol， which indicates that the addition of Ti has little effect on dynamic recrystallization behavior of the high-temperature austenite. The critical strain and kinetic models for dynamic recrystallization are also established.