热轧双相钢动态连续冷却转变及微观取向分析

Dynamic Continuous Cooling Transformation and Micro-orientation of Hot Rolling Dual Phase Steel

采用Gleeble1500热力模拟试验机对马氏体双相钢的形变奥氏体连续冷却转变曲线(CCT曲线)进行了测定,利用光学显微镜对组织进行了观察,利用电子背散射对微观取向进行了统计分析。结果表明,当冷速大于5℃/s时,有马氏体生成,随着冷却速度的增加,马氏体的含量增多,同时出现少量的贝氏体组织;当冷速为30℃/s时,其组织细小,岛状马氏体分布均匀,{111}纤维织构的体积分数异常增加。

The deformation austenite CCT curve of martensite dual phase steel was measured by thermo-dynamic simulation tester Gleeble1500.The microstructure was observed by optical microscope;the micro-orientation was analyzed statistically by electron backscattered diffraction（EBSD）.The results show that the martensite begins to form when cooling velocity is greater than 5 ℃/s.The martensite content increases with the cooling velocity increasing.At the same time,a few bainite appears;when cooling velocity is 30 ℃/s,the microstructure is fine and island martensite uniformly distributes,the volume ratio of {111} fiber texture unconventionally increases.