利用相变与扩散理论,建立了GCr15钢离异共析转变过程中临界过冷度的物理模型,分析了影响临界过冷度的因素,并通过实验对该模型进行了验证。结果表明,GCr15钢发生离异共析转变时,未溶碳化物的粒径越小、越多时,发生离异共析转变的临界温度越低。并且,理论计算结果与实验所得结果吻合。 Based on the theory of phase transformation and diffusion, a physical model of critical undercooling in GCr15 steel during galvanic eutectoid transformation was established. The factors affecting the critical undercooling were analyzed. The model was verified by experiments. The results show that the smaller the grain size of the undissolved carbides, the lower the critical temperature at which the dissociation eutectoid transformation occurs when the GCr15 steel undergoes the ectopic eutectoid transformation. And, the theoretical calculation results are consistent with the experimental results.