通过对覆层用Deform-3D的模拟、金相实验和硬度测试,分析了热锻模具修复层温度变化规律以及组织和性能变化。结果表明:锻模工作过程中循环升温和降温速度较快,有利于碳原子和铁原子的扩散,覆层发生反复的回火再结晶,晶粒平均尺寸长大到180μm。微观组织由回火索氏体+下贝氏体+回火马氏体(平均硬度530 HV)转变为回火索氏体+贝氏体+合金碳化物Cr7C3、Mo2C形成的机械混合物,导致表层的强度严重下降,塑性韧性有所降低。 Through the simulation of the Deform-3D coating, metallographic test and hardness test, the change law of the temperature of the repaired layer and the change of the microstructure and properties were analyzed. The results show that the cycle temperature and cooling rate are faster during forging operation, which is favorable for the diffusion of carbon atoms and iron atoms. The recrystallization of the coating occurs by repeated tempering, and the average grain size grows up to 180μm. The microstructure was transformed from tempered sorbite + lower bainite + tempered martensite (average hardness 530 HV) to a mechanical mixture of tempered sorbite + bainite + alloy carbides Cr7C3, Mo2C, resulting in a superficial layer A serious decline in the strength, plastic ductility decreased.