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建立了界面反应-扩散混合控制模型用于描述先共析铁素体的台阶生长过程.考虑C原子长程扩散和界面反应对铁素体生长的共同控制作用,建立了混合控制机制下先共析铁素体生长动力学的理论模型.运用该模型对先共析铁素体的台阶生长过程进行了模拟,提出了决定先共析铁素体生长机制的控制因子S.S因子包含了碳扩散、界面迁移、相变温度以及成分的作用.通过该因子可判别是C原子长程扩散还是界面反应在先共析铁素体生长中起主导作用.当S较小时,铁素体生长以界面控制为主;当S较大时,铁素体的生长以扩散控制为主.对Fe-1%C(原子分数)合金在720℃的等温γ→α转变进行了模拟,所得结果与文献报道的实验结果符合较好.
An interfacial reaction-diffusion hybrid control model is established to describe the step growth of pro-eutectoid ferrite.Considering the common control of the long-distance diffusion of C-atoms and the interfacial reaction on ferrite growth, a hybrid eutectoid The theoretical model of ferrite growth kinetics was established.Using this model, the step growth of pro-eutectoid ferrite was simulated and the control factor for determining the pro-eutectoid ferrite growth mechanism was proposed.The SS factor contains carbon diffusion, Migration, phase transition temperature and the role of composition.It can be identified by this factor is the long-distance diffusion of C atoms or interface reaction in the primary eutectoid ferrite growth plays a leading role.When S is small, the ferrite growth dominated by the interface The growth of ferrite mainly dominated by diffusion when S was large.The isothermal γ → α transition of Fe-1% C (atomic fraction) alloy at 720 ℃ was simulated and the results obtained were in agreement with the experimental results reported in the literature In line with the better.