The effect of the initial starting microstructures on the austenite reverse transformation kinetics is thoroughly studied in low-carbon steel. The different initial starting microstructures including the ferrite + pearlite, bainite, and martensite are obtained through varied forward transformation. It is found that the bainite phase demonstrates highest reverse transformation rate while the ferrite + pearlite shows the lowest transformation rate. The above observation can be explained through the different grain size of the initial starting microstructures as the grain boundaries could act as the nucleation sites for austenite reverse transformation. The explanation is further substantiated based on the consideration of the reverse transformation kinetics from the martensite microstructure with different grain size.

中文翻译：

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起始组织对低碳钢逆相变动力学的影响

在低碳钢中，已充分研究了初始起始组织对奥氏体反向转变动力学的影响。通过变化的正向转变获得了包括铁素体+珠光体，贝氏体和马氏体在内的不同的初始起始微观结构。发现贝氏体相表现出最高的反向转化率，而铁素体+珠光体表现出最低的转化率。可以通过初始起始微观结构的不同晶粒尺寸来解释上述观察结果，因为晶界可以作为奥氏体逆相变的成核位点。基于对具有不同晶粒尺寸的马氏体组织的反向转变动力学的考虑，进一步证实了该解释。