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运用固体与分子经验电子理论(EET),对Nb、Ti、V3种不同Fe-M-C合金系fcc铁基体(α)、析出的B1型碳化物(ξ)和α/ξ共格界面区(σ)各晶胞价电子结构进行了计算;在此基础上,通过共价键能将EET与离散点阵平面/最近邻断键(DLP/NNBB)模型结合,对以上3种不同合金系的B1型碳化物与bcc铁基体共格界面能进行了理论计算与分析。计算结果表明,合金元素在α/ξ界面区产生偏聚作用,增强了共价键络,产生了固溶强化作用;随着含碳量的增加,C-M偏聚作用增强,界面能逐渐增大;α/ξ共格界面能随温度增加而略有下降,变化范围为1.10～1.45J/m2,与相关文献所得结果一致,Fe-Nb-C合金系α/ξ共格界面能随温度下降最快;Fe-Nb-C合金系α/ξ共格界面能最大,故Nb元素对相变过程晶粒细化效果最好;随着合金元素含量的增加,固溶于铁基体和界面区的含碳量减少,偏聚作用减小,α/ξ共格界面能缓慢下降。
The solid-state and molecular empirical electron theory (EET) was used to study the effect of fcc iron matrix (α), precipitated B1 carbide (ξ) and α / ξ coherent interface area ) On the basis of which the EET can be combined with the discrete lattice plane / nearest neighbor bond (DLP / NNBB) model. Based on these results, Type carbides and bcc iron matrix coherent interface can be a theoretical calculation and analysis. The calculated results show that the alloying elements produce segregation at the α / ξ interface, which enhances the covalent bond and solid solution strengthening. As the carbon content increases, the segregation of CM increases and the interfacial energy increases ; the α / ξ coherent interface can slightly decrease with the increase of temperature, and the variation range is 1.10 ~ 1.45J / m2. It is consistent with the related literature that the α / ξ coherent interface of Fe-Nb- The fastest; the α / ξ co-interface of the Fe-Nb-C alloy system is the largest, so the grain refinement effect of the Nb element is the best for the phase transformation process; with the increase of alloying elements, Carbon content decreases, partial polymerization decreases, α / ξ coherent interface can be slowly decreased.