等离子弧焊接熔池和小孔形成过程数值分析  

Numerical Simulation of Molten Pool and Keyhole Formation during Plasma Arc Welding

作　　者：邱涛 李天庆[1] 陈长新 王昊[1] 陈璐 QIU Tao;LI Tian-qing;CHEN Chang-xin;WANG Hao;CHEN Lu(School of Material Science and Engineering,Jiangsu University,Jiangsu Zhenjiang 212013,China)

机构地区：[1]江苏大学材料科学与工程学院,江苏镇江212013

出　　处：《精密成形工程》2023年第8期178-190,共13页Journal of Netshape Forming Engineering

基　　金：国家自然科学基金(51605201);江苏大学大学生创新创业训练计划(20231222)。

摘　　要：目的研究等离子弧焊接穿孔过程中熔池内部的金属流动情况和小孔动态变化过程。方法通过“传热-熔池流动-小孔”之间的相互耦合关系,建立了等离子弧焊接穿孔过程的数值分析模型,通过VOF方法追踪了小孔界面,采用FLOW-3D软件模拟了等离子弧焊接熔池和小孔的形成过程,定量计算了等离子弧焊接温度场、熔池流场及小孔形状;分析了等离子弧焊接熔池和小孔行为;并通过等离子弧焊接实验数据验证了模拟结果。结果当焊接时间为0~1.0 s时,小孔深度曲线与熔深曲线几乎相同,小孔底部紧贴熔池底部;在2.8s以后,小孔深度曲线与熔深曲线有一定距离,小孔深度曲线在一定范围内波动,等离子弧焊接电弧挖掘作用到达极限,电弧压力与其他力达到平衡状态。模拟的焊缝熔深为8.04mm、熔宽为13.20mm,实验测得的焊缝熔深为8.00 mm、熔宽为13.42 mm。结论构建的随小孔动态变化的曲面热源模型和电弧压力模型可以描述等离子弧焊接过程中的电弧热-力分布;模拟出了等离子弧焊接熔池和小孔动态演变过程;模拟得到的等离子弧焊接焊缝形貌与实验测得的焊缝形貌基本吻合。The work aims to study the metal flow and keyhole dynamic evolution in the molten pool during plasma arc welding.A numerical analysis model of the plasma arc welding process was established with considering the coupling relationship among heat transfer,metal flow in the molten pool and keyhole.The FLOW-3D software was used to simulate the molten pool and keyhole formation of plasma arc welding.The temperature field,the fluid flow in the weld pool and the keyhole shape were calculated quantitatively.The behavior of the molten pool and keyhole in plasma arc welding were analyzed.And the simulation result was verified with the data of the molten pool experiment.At the time from 0 to 1.0 s,the keyhole depth curve was almost the same as the weld penetration curve,and the bottom of the keyhole was close to the bottom of the molten pool.After 2.8 s,the keyhole depth curve kept a certain distance from the weld penetration curve,and the keyhole depth curve fluctuated within a certain range.The digging effect by plasma arc pressure in plasma arc welding reached the limit,and the plasma arc pressure and other forces reached the equilibrium state.The simulated weld penetration depth and penetration width were 8.04 mm and 13.20 mm,respectively,while the experimental weld penetration depth and penetration width were 8.00 mm and 13.42 mm,respectively.The curved surface heat source model and the arc pressure model constructed can reflect the heat-force distribution of arc during plasma arc welding.The dynamic evolution of the molten pool and the keyhole during plasma arc welding is simulated.The simulation results agree with the experimental data basically.

关 键 词：等离子弧焊接 熔池 小孔 热源模型 数值分析 

分 类 号：TG456.2[金属学及工艺—焊接]