低温处理对3Cr2MoCoWV热锻模具钢性能及组织的影响

Effects of low temperature treatment on mechanical properties and microstructure of 3Cr2MoCoWV hot working die steel

探讨了低温处理工艺对3Cr2MoCoWV钢力学性能及微观组织的影响。利用光学显微镜,SEM和TEM分别对3Cr2MoCoWV钢微观组织和下贝氏体-马氏体复合组织中的残留奥氏体分布形态进行了研究,并采用XRD测量了残留奥氏体量。结果表明,低温处理后再进行回火处理,组织中析出了大量弥散细小的ε-碳化物和M2C型碳化物,模具钢的工作温度不超过650℃时,M2C型碳化物可作为钢中的强化相,同时组织中残留的薄膜状残留奥氏体提高了钢的冲击韧性。

Effects of low temperature treatment on mechanical properties and microstructure of 3Cr2MoCoWV hot working die steel were investigated.The microstructure of 3Cr2MoCoWV steel and the morphology of retained austenite in the duplex microstructure of lower bainite-martensite were examined by means of optical microscopy（OM）,scanning electron microscopy（SEM） and transmission electron microscopy（TEM）,respectively.In addition,the volume fraction of retained austenite was measured by XRD.The results show that after low temperature treatment and tempering,a large amount of ε-carbide and M2C carbides are precipitated in the matrix.When the working temperature is lower than 650 ℃,M2C carbide as a strengthening phase of 3Cr2MoCoWV steel and the thin-film retained austenite existed in the microstructure can obviously improve the strength and toughness of 3Cr2MoCoWV steel.