DH780钢的热变形行为及热加工图

采用Thermecmastor-Z热模拟试验机研究了试验钢在800~1150 ℃、应变速率0.01~10 s^-1的热压缩变形行为,并观察变形后显微组织。基于试验数据分析,确定了试验钢在奥氏体区的热变形方程,建立试验钢在0.8真应变下的热加工图。结果表明:试验钢的流变应力和峰值应变随变形温度的升高而减小;试验钢在奥氏体区的热变形激活能为385.91 kJ/mol。根据试验钢功率耗散及流变失稳判据确定最佳热加工工艺参数为热变形温度范围1050~1150 ℃和应变速率0.01~0.1 s^-1。在该范围内,试验钢发生完全动态再结晶,功率耗散系数为17%~32%。

Hot deformation behavior and hot processing map of DH780 steel

Hot deformation behavior of the experimental steel was investigated with a compression test on Thermecmastor-Z simulator at 800-1150 ℃ and strain rate range between 0.01-10 s^-1. The hot deformed microstructure was also observed. Based on the experimental data analysis, the hot deformation equation of the steel in austenite region and the processing map under 0.8 strain were established. The results show that the flow stress and the peak strain decrease with the increase of the deformation temperature. The activation energy in the austenite region is 385.91 kJ/mol. The optimal processing parameters determined by the power dissipation coefficient and the rheological instability are 1050-1150 ℃ and 0.01-0.1 s^-1. In this range, the full dynamic recrystallization occurs in the experimental steel, and the power dissipation coefficient is 17%-32%.