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采用相场法研究了Fe-C-Mn三元合金在临界区等温过程中发生的奥氏体-铁素体相变。基于Gibbs自由能守恒理论,在相场模型中考虑了替换型元素Mn在奥氏体/铁素体相界面内扩散所导致的自由能耗散,描述了Fe-C-Mn三元合金中因Mn在相界面偏聚所导致的相变停滞和相变不完全现象。利用相场模型研究了Mn含量对奥氏体-铁素体相变微观组织转变和相变动力学的影响。结果表明,随着Mn含量的增加,铁素体相的转变速率和体积分数降低,Mn在奥氏体/铁素体相界面内扩散所导致的溶质拖曳现象越明显,相变不完全程度加剧。
The phase-field method was used to study the austenite-ferrite transformation of Fe-C-Mn ternary alloy in the isothermal process of critical region. Based on the Gibbs theory of free energy conservation, the free energy dissipation caused by the diffusion of the substitutional element Mn in the austenite / ferrite interface was taken into account in the phase field model. It is described that the Fe-C-Mn ternary alloy Phase transition stagnation and phase transition caused by the segregation of Mn at the phase interface are incomplete. The effect of Mn content on the microstructure and transformation kinetics of austenite-ferrite transformation was investigated by phase-field model. The results show that with the increase of Mn content, the transformation rate and volume fraction of the ferrite phase decrease, and the solute drag phenomenon caused by the diffusion of Mn in the austenite / ferrite interface becomes more obvious. The incomplete transformation .