控轧控冷过程中X80级管线钢的组织演变

Microstructure evolution of X80 pipeline steel during TMCP process

通过Gleeble3800热模拟机探究X80级管线钢控轧控冷过程中的组织演变规律利用拉伸试验机、金相显微镜(OM)、扫描电镜(SEM)和透射电镜(TEM)对试验钢的力学性能和显微组织进行了研究。结果表明,随着钢的板厚规格减小,准多边形铁素体晶粒尺寸减小,强度升高。450℃模拟卷取过程中准多边形铁素体形核可进一步发生长大。富碳贝氏体组织主要是在450℃模拟卷取过程中由碳化物析出和相变所得的板条贝氏体组织组成,钢中形成的富碳贝氏体组织构成了带状组织。

The research of microstructure evolution in X80 pipeline steel during TMCP process was carried out by Gleeble3500 thermal simulation machine.The mechanical properties and microstructure of the tested steel were investigated by mechanical property testing machine,optical microscope（OM）,scanning electron microscope（SEM）,and transmission electron microscope（TEM）.The results show that with the decrease of the thickness of the steel plate,the grain size of quasi-polygonal ferrite decreases and the strength increases.The quasi-polygonal ferrite core can grow up further in simulating coiling process at 450℃.Carbon-rich bainite is mainly composed of carbide precipitation and lath bainite formed in phase transition during the simulating coiling process at 450℃,which forms the banded structure in the pipeline steel.