CF钢及其氢行为的电子理论研究

应用余氏理论(EET)对CF钢及其氢介入后的价电子结构参数进行计算分析,研究了主要合金元素Cr、Mn、Mo对CF钢的强韧性能及氢在其中扩散聚集行为的影响,对解析CF钢的物理本质做出新的探索.研究结果表明,合金元素的加入使CF钢在具有高强度的同时,保持了较高韧性,并且Cr、Mn、Mo对合金的强化作用依次递增,随着合金元素种类增多,强化作用更加显著.同时含碳合金结构单元对氢表现为排斥效果,其晶胞自身作为一种强障碍妨碍氢穿过,无碳合金晶胞是氢的强陷阱,降低了氢的扩散速度,这是CF钢焊接裂纹敏感性低的重要原因.提出参量Bh和nHT,前者描述了含碳结构单元抵御氢进入的能力,后者描述了当氢进入后,晶胞出现脆化的程度.这对利用EET理论研究氢对材料的影响提供了新的价电子结构参数.

Study of electron theory of CF steel and behavior of hydrogen

The valence electron structures of CF steel and that of hydrogen-included CF steel was calculated and analyzed by applying empirical electron theory of (EET).Influence of Cr,Mn and Mo on strength and toughness of CF steel diffusion and assembly behavior of hydrogen was investigated,so that a new exploration for realizing the essence of CF steel was made.The results show that,when alloy elements dissolved,CF steel not only possesses high strength but also retains excellent toughness.Along with the increase of Cr,Mn and Mo,the strengthening effect successively increases.In addition,using more varieties of alloy elements,the strengthening effect becomes even more obvious.The cells only with alloy elements and carbon repel the hydrogen and block hydrogen's drilling through it as a firm barrier.However,the cells only with alloy elements only trap the hydrogen and slow down diffusing velocity of the hydrogen.These are important reasons of low sensitivity to welding crack in CF steel.Two parameters,B_h and n~H_T,were presented,the former denotes the ability of cells with carbon to avoid hydrogen entering and,the latter expresses the brittle behavior of cells due to hydrogen entering,offering EET new valence electron parameters that may describe the influency of hydrogen on materials.