冷处理温度对1Cr20Co6Ni2WMoV钢组织和硬度的影响

Effect of cold treatment temperature on microstructure and hardness of 1Cr20Co6Ni2WMoV steel

采用SLX-50程序控制深冷箱研究了马氏体热强钢1Cr20Co6Ni2WMoV经淬火(1060℃×1h)、不同温度(-30℃、-70℃、-196℃×2h)冷处理、回火(640℃×2h)后的微观组织及硬度变化。研究结果表明,经不同温度冷处理后,钢中析出M23C6型碳化物。随冷处理温度的降低,马氏体板条宽度减小,析出相M23C6数量增多,残余奥氏体的含量降低,钢的硬度值升高。

Cold treatment at -30℃, -70℃ and - 196℃ for 2h by using a SLX-50 cryogenic box with program control and then tempering at 640℃ for 2h, was performed on a quenched martensitic heat-resistant steel, 1Cr20Co6Ni2WMoV. The effect of cold treatment on microstructure and hardness of the steel was studied. The results show that only M23 C6 carbides precipitation is observed in the steel after cold treatment. With decrease of the cold treatment temperature, the size of martensite laths reduces, the amount of M23 C6 precipitates increases, and the amount of retained austenite decreases leading to the increase of hardness of the steel.