高、低铌X80钢动态再结晶的分析与对比

Analysis and comparison on dynamic recrystallization of high-Nb and low-Nb X80 pipeline steel

利用热-力模拟试验机对高铌和低铌X80管线钢的动态再结晶行为进行了研究,结果表明:与低铌X80管线钢相比,高铌X80管线钢需在较高的变形温度和较低的应变速率下才能发生动态再结晶.高铌和低铌X80钢的动态再结晶激活能分别为342.95,306.02 kJ/mol,动态再结晶模型分别为z=4.091σp5.992,z=0.662σp5.643.高铌抑制了奥氏体的动态再结晶,延迟了应力-应变曲线向动态再结晶型转变,进而提高了奥氏体的再结晶终止温度.

Dynamic recrystallization behavior of high-Nb and low-Nb X80 pipeline steel was studied by thermal-mechanical simulation tester.Some conclusions were obtained：the high-Nb steel had the behavior of dynamic recrystallization at a higher temperature and a lower strain rate compared with the low-Nb steel;the dynamic recrystallization activation energy of the high-Nb and low-Nb pipeline steel were 342.95kJ/mol and 306.02kJ/mol respectively,and the models of dynamic recrystallization were Z=4.091 σp^5.992,Z=0.662 σp^5.643;the high-Nb content could restrain the dynamic recrystallization of austenite and delay the transformation of stress-strain curve towards dynamic recrystallization,thereby increasing the recrystallization termination temperature.