3Cr2W8V钢的热处理工艺优化

Optimization of Heat Treatment Technology for 3Cr2W8V Steel

利用徕卡金相显微镜、硬度计、电子万能试验机等手段研究了不同的预备热处理工艺、淬火和回火工艺对3Cr2W8V钢组织、力学性能和断口形貌的影响。结果表明,当淬火温度在1020℃至1180℃变化时,3Cr2W8V钢的组织主要为马氏体,当温度上升至1060℃以上时,晶界上开始出现明显的残余奥氏体;当回火温度在500℃至700℃变化时,在相对较低的温度下组织主要为回火马氏体,在600℃时开始出现回火托氏体;随着回火温度的升高,硬度呈现出先升后降的趋势,而冲击韧性表现出相反的趋势;从宏观断口形貌来看,随着回火温度的升高,断口表面由凹凸不平逐渐过渡为平整,再转变为凹凸不平;与传统热处理工艺相比,新工艺获得了更优异的性能,同时热处理时间缩短了至少2h。

The effects of different pre-heat treatment processes,quenching and tempering processes on the microstructure,mechanical properties and fracture morphology of 3Cr2W8V steel were studied by means of Leica metallographic microscope,hardness tester and electronic universal testing machine.The results show that when the quenching temperature changes from 1020℃to 1180℃,the microstructure of 3Cr2W8V steel is mainly martensite,and when the temperature rises above 1060℃,obvious retained austenite begins to appear on the grain boundary.When the tempering temperature changes from 500℃to 700℃,the microstructure is mainly tempered martensite at relatively low temperature,and the tempered Trollite begins to appear at 600℃.With the increase of tempering temperature,the hardness increases first and then decreases,while the impact toughness shows the opposite trend.From the macroscopic fracture morphology,with the increase of tempering temperature,the fracture surface gradually transits from uneven to flat and then to uneven.Compared with the traditional heat treatment process,the new process has obtained more excellent properties and shortened the heat treatment time by at least 2 hours.