模拟焊后热处理对15CrMo钢组织和力学性能的影响

Effect of simulated post-weld heat treatment on microstructure and mechanical properties of 15CrMo steel

采用光学显微镜、拉伸试验、冲击试验及硬度试验研究了模拟焊后热处理对15Cr Mo钢组织和力学性能的影响。结果表明：经690℃模拟焊后热处理后,15Cr Mo钢的屈服极限、抗拉强度、高温强度、冲击吸收能量以及硬度均有升高的趋势,伸长率有所降低;随着保温时间的延长,屈服强度、抗拉强度、高温强度、冲击吸收能量、硬度以及伸长率均呈降低趋势。在690℃模拟焊后热处理保温不同时间后,15Cr Mo钢的显微组织均为回火贝氏体＋铁素体,随着保温时间的延长,钢中铁素体数量逐渐增多,晶粒尺寸增大。

The influence of simulated post-weld heat treatment（ SPWHT） on the microstructure and mechanical properties of 15 Cr Mo steel was studied by OM,tensile test,impact test and hardness test. The results indicate that the yield strength,tensile strength,high temperature strength,impact absorbed energy and hardness are improved by the SPWHT,while the elongation is lowered. With prolonging of the SPWHT holding time,the yield strength,tensile strength,high temperature strength,impact absorbed energy,hardness and elongation show decreasing trend. The microstructure of 15 Cr Mo steel is all tempered bainite ＋ ferrite after SPWHT at 690 ℃ holding for different time,and with prolonging of the holding time,the amount of ferrite increases gradually and the grain size grows larger.