Fe-C合金焊接熔池凝固过程CET转变的数值模拟  

Numerical simulation of CET transformation in solidification of Fe-C alloy weld pool

作　　者：张敏[1] 徐蔼彦 汪强[1] 李露露[1] 

机构地区：[1]西安理工大学材料科学与工程学院,西安710048

出　　处：《焊接学报》2016年第2期5-8,54,共5页Transactions of The China Welding Institution

基　　金：国家自然基金资助项目(51274162);国家高技术研究发展计划(863计划)(2013AA031303);陕西省自然科学基金资助项目(2012JM6003);陕西省教育厅产业化培育项目(No.2012.JC16);西安市科技计划项目(No.CX12163)

摘　　要：基于元胞自动机方法建立了枝晶生长的数值模型,应用该模型模拟了Fe-C合金焊接熔池凝固期间柱状晶向等轴晶(CET)转变过程中枝晶生长形貌与溶质浓度分布状况.模拟过程主要考虑不同扰动振幅和冷却速率对柱状晶向等轴晶转变的影响.结果表明,随着时间步长增大,晶粒数逐渐增多,最终趋于稳定值;当冷却速率增加时,生长速度增大,枝晶生长的越充分,显微偏析越严重,而CET转变所需时间越短;当扰动振幅增大时,一次枝晶生长的越细,二次、三次枝晶竞争越激烈.A new model of dendritic growth based on cellular automaton method was developed to simulate the columnarto-equiaxed grain transition and the distribution of solute concentration during solidification in Fe-C alloy weld pool. The influences of different disturbance amplitudes and different cooling rates on the columnar-to-equiaxed grain transition were considered. The results indicate that the grains increased gradually and became stable eventually. When the cooling speed increased,the growth rate increased and the microsegregation was more serious, and the columnar-to-equiaxed grain transition happened easier. Meanwhile,the disturbance amplitude affected the dendritic morphology and especially the growth of secondary and tertiary dendrite arms.

关 键 词：FE-C合金 焊接熔池 枝晶形貌 溶质浓度 

分 类 号：TG292[金属学及工艺—铸造]