磷对钢冷脆行为影响的相界面电子结构分析

基于固体与分子经验电子理论（EET），计算了α-Fe／α-Fe-MT^X矿和α—Fe／Fe3P的相界面电子结构，并利用相界面电子密度差△ρ分析了非金属元素P引起冷脆的根本原因。计算结果分析认为，非金属元素P与基体α-Fe形成的α-Fe／α-Fe—P相界面比与Si、Mn、Mo元素形成的相界面的电子密度差△ρ大，产生的界面应力也较大，从而提高了合金强度，降低了塑性和韧性；Fe3P与基体α-Fe形成的α-Fe／Fe3P相界面电子密度差在一级近似下不连续，强化效果显著，韧性、塑性降低明显，这是P引起冷脆的根本原因。这些理论分析与实验事实符合得很好。

Analysis of Phosphorus Effect on Cold Short Behavior of Steel with Electron Structure Parameters of Phase Interface

Based on the empirical electron theory of solid and molecule, the electron structure of α-Fe/α-Fe-M^x and α-Fe/Fe3P phase interfaces were calculated, the real reason for phosphorus to cause cold short of steel with the interface electron density difference Δρ was analysised. The calculation results expatiated that the electron density difference Δρ of the α-Fe/α-Fe-P phase interface was larger than those of phase interfaces formed by Si, Mn and Mo elements, so that the interface stress caused by the α-Fe/α-Fe-P phase interface was larger than that of other phase interfaces, and then the strength of alloy was enhanced greatly and its plasticity and toughness were decreased remarkably. The electron density difference Δρ of α-Fe/Fe3P phase interface formed by Fe3P and α-Fe matrix was discontinuous under first order of approximation, so that both the increase of strengthening effect and the decrease of plasticity and toughness were dramaticaly generated, thereby the cold short of phosphorus was explained. The theoretical analyses agreed well with the experimental facts.