X70管线钢的CCT曲线研究

Research on CCT Curve of X70 Pipeline Steel

利用Gleeble 1500热模拟实验机对低碳微合金X70管线钢进行连续冷却转变实验,并绘制未变形及变形条件下的连续冷却转变(CCT)曲线,同时研究冷速及变形对实验钢组织和硬度的影响。结果表明:实验钢的连续冷却转变产物主要有铁素体、珠光体及贝氏体组织;随冷速的增加,实验钢相转变温度下降;随变形程度的增加,相同冷速实验钢的相变温度略有升高。

The law of phase change of X70 pipeline steel during continual cooling was studied by Gleeble 1500. The CCT curves of X70 pipeline steel were drawn by adopting dilatometer and metallographic method, and the effects of cooling rates on microstructure and hardness of the steel were studied. The experimental results show that the microstructure of the steel are mainly Fen＇ire, Perlite and Bainites. With the increase of cooling rate, the phase transition temperature of tested steel decreases. With the increase of deforming degree, the phase transition temperature of tested steel increases slightly as in the same cooling rate.