焊接热循环下Nb原子非平衡晶界偏聚行为的动力学建模  

Kinetic modeling of non-equilibrium grain boundary segregation behaviour of Nb during welding thermal cycle

作　　者：林轩艺 王红鸿[1,2] 鄢文泽 LIN Xuanyi;WANG Honghong;YAN Wenze(State Key Laboratory of Refractories and Metallurgy,Wuhan University of Science and Technology,Wuhan 430081,China;Faculty of Materials Science,Wuhan University of Science and Technology,Wuhan 430081,China)

机构地区：[1]武汉科技大学省部共建耐火材料与冶金国家重点实验室,湖北武汉430081 [2]武汉科技大学材料学部,湖北武汉430081

出　　处：《武汉科技大学学报》2025年第1期14-24,共11页Journal of Wuhan University of Science and Technology

基　　金：国家自然科学基金面上项目(51971165).

摘　　要：采用Gleeble-3500型热模拟机,对3种不同Nb含量(0.180%、0.085%、0.025%)的HSLA钢在不同冷却速率下的焊接热循环过程进行模拟,借助电子显微探针(EPMA)技术对Nb原子的非平衡晶界偏聚行为进行表征,得到了不同Nb含量和冷却速率下晶界处Nb原子偏聚量,基于非平衡晶界偏聚动力学理论,计算得到空位形成能为1.403 eV,同时确定了Nb含量分别为0.180%和0.085%钢中Nb原子非平衡偏聚的临界时间常数分别为7.59×10^(3)和6.0×10^(3)。进一步将Nb原子-空位复合体的扩散系数作为变量,计算并修正得到了其与等效时间的函数关系,最终建立了焊接热循环条件下Nb原子非平衡偏聚的修正动力学方程。The welding thermal cycles of HSLA steels with three different Nb contents(0.180%,0.085%,0.025%)were simulated using the Gleeble-3500 thermal simulator under varying cooling rates.The non-equilibrium grain boundary segregation behavior of Nb atoms was characterized by electron probe microanalysis(EPMA),and the Nb atom segregation at grain boundaries was quantified under different Nb contents and cooling rates.Based on the non-equilibrium grain boundary segregation kinetics,the vacancy formation energy was determined to be 1.403 eV.Additionally,the critical time constants for non-equilibrium segregation of Nb atoms in steels with 0.180%and 0.085%Nb content were calculated as 7.59×10^(3)and 6.0×10^(3),respectively.Furthermore,by treating the diffusion coefficient of Nb atom-vacancy complexes as a variable,the relationship between the diffusion coefficient and the equivalent time was calculated and revised,leading to the establishment of a corrected kinetic equation for non-equilibrium segregation of Nb atoms under welding thermal cycles.

关 键 词：NB HSLA钢 焊接热循环 非平衡晶界偏聚 扩散系数 动力学方程 

分 类 号：TG401[金属学及工艺—焊接]