回火工艺对Cr-Mo-V钢组织和力学性能的影响

Effect of Tempering Process on Microstructure and Mechanical Properties of Cr-Mo-V Steel

对Cr-Mo-V钢进行回火工艺试验,研究不同回火温度和回火时间对Cr-Mo-V钢微观组织和力学性能的影响。试验结果表明:回火工艺直接影响微观组织中析出碳化物的数量、大小、形状、分布及马氏体形态。随着回火时间的延长,试验钢抗拉强度、屈服强度先减小、后增加、最后再减小,冲击功先增加、然后减少,在回火温时间120 min时,强度与韧性达到最佳匹配;随着回火温度的增加,试验钢抗拉强度、屈服强度先增加、后减小,冲击功先增加、后减少、最后再增加,在回火温度为665℃时,强度达到最大值。综合考虑试验钢的要求,得出回火温度665℃+回火时间120 min为最佳回火工艺。

The effects of tempering temperature and time on the microstructure and mechanical properties of Cr-Mo-V Steel are studied.The results show that the amount,size,shape,distribution and morphology of martensite in microstructure are directly affected by tempering process.With the extension of tempering time,the tensile strength and yield strength first decrease,then increase and finally decrease,and the impact energy first increases and then decreases.At the tempering temperature of 120 min,the strength and toughness reach the best match,the tensile strength and yield strength of the test steel first increase and then decrease,and the impact energy first increases,then decreases and finally increases.Considering the requirements of test steel,it is concluded that tempering temperature 665℃+tempering time 120 min is the best tempering process.