摘要
P91是一种新型的耐热高强钢,广泛用于制造大型火力发电机组中的各种耐热管道,它不同于一般的焊缝钢管,主要是采用高温塑性成形方法生产的,对其高温力学性能进行研究的意义重大。在Gleeble 1500D热力学模拟机上进行大量试验,测得了P91不同变形条件下的真实应力一真实应变曲线。试验曲线表明,P91在变形过程中存在动态再结晶现象,且随着温度的升高和应变速率的降低,动态再结晶现象越易发生,临界应变量越小,流变应力下降越显著。使用Origin 7.0对各种变形条件下的峰值流变应力进行分析,得出流变应力基于Zener-Hollomon参数的函数关系,建立了P91高温流变应力的数学模型。
P91 is a new kind of heat-resistant high-tensile steel. It is widely used in kinds of heat-resistant pipes in big thermal power plants, mainly produced by hot plastic deformation unlike common welding steel pipes, and investigations in its high-temperature mechanical properties are very significant. Lots of experiments on the thermo-mechanical simulator Gleeble 1500D are operated, and the true strain-true stress curves under different deforming conditions are obtained. Dynamic recrystallization during deformation is observed as the experimental curves show, and as the deformation temperature rises or the strain rate decreases, dynamic recrystallization happens at an earlier critical strain and drags the flow stress down more notably. By the analysis of the flow stresses in different conditions with Origin 7.0, the relationship among flow stress, temperature and strain rate known as Zener-Hollomon parameter is found, the math model of P91 ＇s flow stresses at high temperature is established.
出处
《机械工程学报》
EI
CAS
CSCD
北大核心
2008年第6期243-247,共5页
Journal of Mechanical Engineering
