A-TIG焊熔深增加机理的数值模拟  

Numerical Simulation of the Mechanism for Penetration Increasing of A-TIG Welding

作　　者：张瑞华[1] 尹燕[1] 樊丁[1] 片山圣二[2] 

机构地区：[1]兰州理工大学甘肃省有色金属新材料省部共建国家重点实验室,兰州730050 [2]大阪大学接合科学研究所

出　　处：《机械工程学报》2008年第5期175-180,共6页Journal of Mechanical Engineering

基　　金：甘肃省自然科学基金(0710RJZA064)。

摘　　要：利用自行研制的不锈钢活性剂FS12对A-TIG焊熔深增加机理进行研究。用PHOENICS软件模拟了有、无活性剂时氧元素质量分数、电弧收缩效应等对熔池速度场和温度场的影响。计算结果表明,无活性剂时,熔池液态金属从中心流向四周,再从四周流向熔池底部,形成宽而浅的熔池形状;有活性剂时,熔池液态金属从熔池边缘流向中心,引起向内的两个涡流在熔池上表面中心相遇,汇合后流向熔池中心底部,形成窄而深的熔池形状:表面张力梯度变化是熔深增加的主要原因,电弧收缩影响熔宽,对熔深增加也有一定的影响,但不是主要原因。熔池形状的数值模拟结果与试验结果吻合良好。The mechanism of the increasing of A-TIG welding penetration is studied by using the activating flux developed by ourselves for stainless steel. The effect of flux on the flow and temperature fields of weld pool is simulated by the PHOENICS software. It shows that without flux, the fluid flow will be outward along the surface of the weld pool and then down, resul ting in a flatter weld pool shape. With the flux, the oxygen, which changes the temperature dependence of surface tension grads from a negative value to a positive value, can cause significant changes on the weld penetration. Fluid flow will be inward along the surface of the weld pool toward the center and then down. This fluid flow pattern efficiently transfers heat to the weld root and produces a relatively deep and narrow weld. This change is the main causation of penetration increasing. And arc shrinking can cause the weld width to become narrower and the penetration to become deeper, but arc shrinking not the main causation of penetration increasing. The simulation results of the weld pool shape accord with the experiment results well.

关 键 词：A-TIG焊 活性剂 熔深增加 PHOENICS 

分 类 号：TG401[金属学及工艺—焊接]