Cr在钢中的价电子结构分析

Analysis on Valence Electron Structure of Cr in Steel

应用固体与分子经验电子理论(即余氏理论EET)分别计算了Cr溶入到奥氏体和马氏体中的价电子结构,从价电子结构层次分析了Cr在钢中的作用机理。结果表明:Cr溶入到奥氏体后晶胞内最强健的共价电子对数nA值降低,减小了马氏体相变时的阻力,从而降低了Ms点。Cr溶入到马氏体后晶胞内最强键的nA值明显增强,提高了钢的强度和硬度。马氏体Fe-C-Cr晶胞最强键的nA值超过了奥氏体Fe-C-Cr晶胞对应的键,这是马氏体比奥氏体硬度高的原因。

Depending on the empirical electron theory of solids and molecules,the valence electron structure of Cr in austenite and martensite was calculated in order to determine the valence electron structure of Cr in steels.The results show that when Cr is dissolved into austenite,the bonding strength of the strongest bonding nA in unit cell is lower so that the resistance of martensite decreases and the amounts of the retained austenite is low.When Cr is dissolved into martensite,the bonding strength of the strongest bonding nA in unit cell becomes stronger and improves the hardness of the steel;the bonding strength nA of the strongest bonding in Fe-C-Cr unit cell of martensite is much stronger than one of the strongest bonding in Fe-C-Cr unit cell of austenite,which may be the reasons for higher hardness in martensite.