Ferrite formation in Fe-C alloys during austenite decomposition under non-equilibrium interface conditions
Ferrite formation in Fe-C alloys during austenite decomposition under non-equilibrium interface conditions
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DOI：
10.1016/s0921-5093(97)00365-1
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发表时间：
1997-09
期刊：
影响因子：
6.4
通讯作者：
G. P. Krielaart;J. Sietsma;S. van der Zwaag
中科院分区：
文献类型：
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作者：
G. P. Krielaart;J. Sietsma;S. van der Zwaag
用允许运动α-γ界面上的非平衡条件的数值模型研究了二元Fe-C合金过饱和奥氏体分解过程中铁素体的生长。提出了一种数值方法来考虑扩散生长过程中的非平衡界面条件。在该模型中，界面迁移的驱动力是由界面上奥氏体铁素体晶格的化学势之差给出的。界面移动引起的碳重排影响了相变过程中界面迁移的驱动力，从而建立了混合生长控制模式。据预测，控制模式将从极低过冷度时的基本扩散控制模式转变为深过冷度时的基本界面控制模式。该模型的计算结果与几组实验生长速率和部分相变Fe-C合金的碳浓度分布符合得很好。
The growth of ferrite during the decomposition of supersaturated austenite in binary Fe-C alloys is studied using a numerical model that allows non-equilibrium conditions at the moving α-γ-interface. A numerical method is presented to account for non-equilibrium interface conditions during diffusional growth. In this model, the driving force for interface migration is given by the difference of the chemical potentials of the austenitic and the ferritic Fe-lattice at the interface. Carbon rearrangement, resulting from the movement of the interface, affects the driving force for interface migration during the transformation, thus establishing a mixed mode of growth control. The mode of control is predicted to vary from essentially a diffusion controlled mode at very low undercooling towards essentially an interface controlled mode at deep undercoolings. The results from this model are in good agreement with several sets of experimental growth rates and the carbon concentration profiles of partially transformed Fe-C alloys.