P91合金钢热变形力学行为的实验

Experimental research on mechanical property of P91 under high temperature thermal deformation

利用Gleeble-3500热模拟试验机对P91合金钢进行高温压缩实验,得到了该合金钢在不同温度1000℃、1100℃、1150℃和1200℃,不同应变速率1s-1、0.1s-1、0.01s-1和0.001s-1条件下的真应力-真应变曲线。曲线形态基本符合普通结构钢的热变形力学特征。采用包含Zener-Hollomon参数的Arrhenius双曲正弦关系描述P91合金钢的高温流变行为,确定其变形激活能Q=499.89kJ/mol。P91合金钢应力-应变曲线的典型特征是,在大应变时曲线明显上翘。采用有限元数值模拟方法,分析摩擦力对真应力-真应变曲线翘曲的影响,发现除摩擦力外,还存在其他的影响因素。

A set of hot compression experiment of P91 alloy steel was carried out on the Gleeble 3500 thermal-mechanical testing system.The true stress-true strain curves were obtained in the condition of temperature 1000℃,1100℃,1150℃ and 1200℃,and strain rate 1s-1,0.1s-1,0.01s-1 and 0.001s-1.By using the obtained experimental data,the hot deformation activation energy Q of P91 alloy steel was obtained and Q=499.78kJ/mol.It is found out that the true stress-true strain curves of the alloy show upward warping character in larger strain condition.The influence of friction on the upward warping of stress-strain curves was studied by using FEM numerical simulation.The simulated results show that the friction is an important but not sole influence factor.