核电用SA508-3CL钢的热成形行为及加工图

Hot deformation behavior and processing map of SA508-3CL steel

采用Gleeble-1500D热模拟试验机对SA508-3CL钢在变形温度800℃~1 200℃、应变速率0.001s-1~1s-1条件下进行热压缩实验,并将获得的真应力真应变数据引入Arrhenius型本构方程,通过多元线性回归计算,得到了SA508-3CL钢的变形激活能为422.455kJ·mol-1,同时建立了该钢的流变应力本构方程。将功率耗散图与失稳图叠加,得到了SA508-3CL钢在应变量为0.3、0.5和0.7时的热加工图,对在应变量为0.7时的热加工图及金相组织分析表明,该钢的组织缺陷主要是局部流变失稳,该钢的安全加工条件为温度1100℃~1200℃,应变速率0.01s-1~0.1s-1。

Several thermal simulation compression tests were carried out on the Gleeble-150OD simulator for the SA508-3CL steel. The true strain true stress data at temperatures of 800℃-1200℃ and strain rate of 0. 01s-1 ls-1 were obtained. According to these data and Arrhenius type constitutive equation, by using multivariate linear regression analysis, the hot deformation activa- tion energy Q was calculated as 422. 455kJ/mol, and the hot compression constitutive equation about temperature and strain rate was established. By the superposition of the power dissipation map and instability map, the hot processing map of this steel at strains of 0. 3, 0. 5 and 0.7 was developed. Through analysis of the hot processing map and microstructures at strain of 0.7, the main defect is flow localization, and the security processing region of SAS08-3CL steel is at temperature of 1100 ℃-1200℃ and strain rate of 0.01 s-1 -0.1 s-1.