采用Gleeble-3800型热模拟试验机研究了抗大变形管线钢在不同压缩变形条件下的动态再结晶行为, 采用光学显微镜和扫描电镜观察了奥氏体的形貌, 利用线性回归法对真应力-真应变数据进行分析, 得到了试验钢的热变形方程。结果表明: =1 s-1, ε=0.30时, 试验钢发生部分动态再结晶的温度区间为920~1 020 ℃; 在980 ℃, =1 s-1时, 发生部分动态再结晶的应变为0.20~0.40, 而且应变对再结晶晶粒尺寸的影响不大; ε=0.40时, 动态再结晶基本完成, 0.40<ε<0.60, 发生了多轮动态再结晶, 再结晶晶粒尺寸随应变的增大而减小; 试验钢在950~1 100 ℃的热变形激活能为360.365 kJ·mol-1, 应力指数n为4.326 3。

The dynamic recrystallization behavior of high deformability pipeline steel was studied by a Gleeble-3800 thermal simulator under different compression deformation conditions, and the austenite morphology was observed by optical microscopy and scanning electron microscopy. The true stress-true strain data were analysed by linear regression method to obtain thermal deformation equation of the tested steel. The results show that partial dynamic recrystallization temperature zone was 920-1 020 ℃ when =1 s-1 and ε=0.30. The strain for partial dynamic recrystallization was 0.20-0.40 at 980 ℃ and 1 s-1, and the strain had little effects on austenite recrystallization grain size. The dynamic recrystallization completed mainly when ε=0.4, and when 0.40＜ε＜0.60 many times dynamic recrystallization took place, and recrystallization grain size decreased with the increase of strain. The hot deformation activation energy of the tested steel was 360.365 kJ·mol-1 and the stress index was 4.326 3 at 950~1 100 ℃.