中锰钢逆相变退火组织的演变及锰的配分行为

Evolution of ART-annealed microstructure and partition behavior of manganese in medium manganese steel

采用SEM、TEM、STEM、XRD、EBSD等实验分析方法对中锰钢(0.2C5Mn)在奥氏体逆相变不同时间退火过程中的微观组织演变进行了分析。结果表明:中锰钢在650℃短时间逆相变退火时析出大量M3C型碳化物,随着退火时间的延长,逆相变奥氏体形成长大,获得马氏体、奥氏体双相片层状组织。马氏体与逆相变奥氏体晶粒取向服从K-S关系,且两相板条平均宽度在0.5μm左右。退火过程中锰元素出现由淬火组织平均分布逐渐向逆相变奥氏体富集的配分行为,长时间退火后形成体积分数为30%的逆相变奥氏体,抗拉强度为960MPa,屈服强度为500MPa,总伸长率为40%,强塑积高达38.4GPa·%。

Microstructure evolution of medium manganese steel（0.2C5Mn）during austenite reverted（ART）annealing for different time was investigated by SEM,TEM,STEM,XRD and EBSD.The results show that many M3 C type carbide particles precipitate during annealing at 650℃for short time.With increasing of annealing time,reverted austenite forms and grows to produce lamellar structure of martensite and austenite.Crystal orientation between martensite and reverted austenite accords with K-S relationship,and the average width of laths of dual phases is about 0.5μm.In addition,manganese goes to reverted austenite during annealing process and reverted austenite of volume fraction of 30% forms after annealing for a long time with excellent mechanical properties：tensile strength of 960 MPa,yield strength of 500 MPa,total elongation of 40% and product of strength and total elongation of 38.4GPa·%.