含稀土H13钢热变形行为及热加工图研究

摘要

利用Gleeble-3800热力模拟试验机在900~1 200 ℃、0.01~10 s-1的实验条件下,对含稀土H13进行了热压缩.根据获取的流变应力曲线,建立了含稀土H13钢的高温热变形本构方程及热加工图,并分析了变形后的金相组织.结果表明,在高应变速率下流变应力曲线说明了含稀土H13钢具有断续再结晶行为,稀土的加入显著提升了H13钢的应力值,经计算含稀土H13钢的热激活能为573 kJ/mol,适宜的热加工参数为1 050~1 200 ℃、应变速率0.01~1 s-1.稀土的加入拓宽了H13钢的热加工参数范围.%H13 steel containing rare earth was compressed at the temperature of 900-1 200 ℃ and the strain rate of 0.01-10 s-1 by the Gleeble-3800 thermal-mechanical simulator.The constitutive equation and hot processing map of the rare earth H13 steel at high temperature were established according to the obtained flow stress.Meanwhile, the microstructure of the compressed specimens were analyzed by optical microscope.The flow stress showed that the rare earth H13 steel had a discontinuous dynamic recrystallization behavior at the large strain rate and the stress of the rare earth H13 was elevated obviously.The thermal activation energy of the rare earth H13 steel was 573 kJ/mol.The suitable processing parameter of the rare earth H13 steel was within 1 050-1 200 ℃ and the strain rate was within the range of 0.01-0.1 s-1.Therefore, the addition of rare earth has broadened the scope of the hot processing parameters.