Effect of Cr, Mo, and Nb additions on intergranular cohesion of ferritic stainless steel: First-principles determination  

作　　者：李春霞 党随虎 王丽萍 张彩丽 韩培德 

机构地区：[1]Key Laboratory of Interface Science and Engineering in Advanced Materials of Ministry of Education,Taiyuan University of Technology [2]College of Materials Science and Engineering, Taiyuan University of Technology [3]College of Physics and Electronic Engineering, Yangtze Normal University

出　　处：《Chinese Physics B》2014年第3期457-462,共6页中国物理B（英文版）

基　　金：Project supported by the National Natural Science Foundation of China(Grant No.51371123);the Specialized Research Foundation of the Doctoral Program for Institution of Higher Education of China(Grant No.2013140211003);the Science and Technology Research Project of Municipal Education Commission of Chongqin,China(Grant Nos.KJ131308 and KJ131315);the Natural Science Foundation of Science and Technology Commission of Chongqin,China(Grant No.cstc2012jjA90017)

摘　　要：Effects of Cr, Mo, and Nb on the ferritic stainless steel ]2（210） grain boundary and intragranularity are investigated using the first-principles principle. Different positions of solute atoms are considered. Structural stability is lowered by Cr doping and enhanced by Mo and Nb doping. A ranking on the effect of solute atoms enhancing the cohesive strength of the grain boundary, from the strongest to the weakest is Cr, Mo, and Nb. Cr clearly prefers to locate in the intragranular region of Fe rather than in the grain boundary, while Mo and Nb tend to segregate to the grain boundary. Solute Mo and Nb atoms possess a strong driving force for segregation to the grain boundary from the intragranular region, which increases the grain boundary embrittlement. For Mo- and Nb-doped systems, a remarkable quantity of electrons accumulate in the region close to Mo （Nb）. Therefore, the bond strength may increase. With Cr, Mo, and Nb additions, an anti-parallel island is formed around the center of the grain boundary.Effects of Cr, Mo, and Nb on the ferritic stainless steel ]2（210） grain boundary and intragranularity are investigated using the first-principles principle. Different positions of solute atoms are considered. Structural stability is lowered by Cr doping and enhanced by Mo and Nb doping. A ranking on the effect of solute atoms enhancing the cohesive strength of the grain boundary, from the strongest to the weakest is Cr, Mo, and Nb. Cr clearly prefers to locate in the intragranular region of Fe rather than in the grain boundary, while Mo and Nb tend to segregate to the grain boundary. Solute Mo and Nb atoms possess a strong driving force for segregation to the grain boundary from the intragranular region, which increases the grain boundary embrittlement. For Mo- and Nb-doped systems, a remarkable quantity of electrons accumulate in the region close to Mo （Nb）. Therefore, the bond strength may increase. With Cr, Mo, and Nb additions, an anti-parallel island is formed around the center of the grain boundary.

关 键 词：first-principles principle grain boundary cohesion electronic properties ferritic stainless steel 

分 类 号：O469[理学—凝聚态物理]