The formation and structure of Fe-Mn-Ni-Si solute clusters and G-phase precipitates in steels
The formation and structure of Fe-Mn-Ni-Si solute clusters and G-phase precipitates in steels
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DOI：
10.1016/j.jnucmat.2018.03.050
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发表时间：
2018-07
影响因子：
3.1
通讯作者：
D. King;P. Burr;S. Middleburgh;T. M. Whiting;M. G. Burke;M. Wenman
中科院分区：
文献类型：
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作者：
D. King;P. Burr;S. Middleburgh;T. M. Whiting;M. G. Burke;M. Wenman
溶质聚类和g相析出分别在一些低合金和不锈钢中引起硬化现象。密度泛函理论用于研究这些沉淀形成的能量驱动力，通过分析体系的构型和磁熵捕获温度效应。结果表明，与典型A508低合金钢的稀铁素体基体相比，Mn、Ni和Si的富集在热力学上是有利的。我们预测，当体系的铁含量低于10-18 at时，有序g相优先形成，而不是b2型有序结构。%。在没有Fe的情况下，在B2结构中引入空位会自发地发生B2→g相变。
Solute clustering and G-phase precipitation cause hardening phenomena observed in some low alloy and stainless steels, respectively. Density functional theory was used to investigate the energetic driving force for the formation of these precipitates, capturing temperature effects through analysis of the system's configurational and magnetic entropies. It is shown that enrichment of Mn, Ni and Si is thermodynamically favourable compared to the dilute ferrite matrix of a typical A508 low alloy steel. We predict the ordered G-phase to form preferentially rather than a structure with B2-type ordering when the Fe content of the system falls below 10–18 at. %. The B2 → G-phase transformation is predicted to occur spontaneously when vacancies are introduced into the B2 structure in the absence of Fe.