GTA焊接熔池特性的数值模拟

Numerical simulation of melt pool in GTA welding

以GTA焊接熔池为研究对象,建立了304不锈钢材料的移动GTA焊接过程的数学模型,模型中考虑了电磁力、浮力和表面张力.利用大型通用商业软件Phoenics3.4进行数值模拟.通过引入液相分数标量描述界面熔融区,能量方程中将潜热转换为热焓源项,而动量方程则引入Darcy源项,由此建立统一的液固相控制方程,实现在固定网格下求解具有移动界面的熔化和凝固过程.应用该模型计算了不锈钢GTA焊接过程中的熔池形状、工件的温度场和熔池的流场,熔池形状计算结果与实际焊接结果吻合.

Taking the melt pool as investigation object,its mathematical model is developed for GTA welding of stainless steel 304 with moving arc,where the magnetic force,buoyancy,and surface tension are taken into consideration.Numerical simulation of the melt pool is conducted with the large-scale commerical general-purposed software Phoenics3.4.By introducing fractional scalar of the liquid-phase into the discription of melting area at the interface,the potential heat in the energy equation is transformed into the source-term of enthalpy,and the Darcy source-term is introduced into the momentum equation,that a united control equation of liquid-solid-phase is built up and the melting and solidifing processes with moving interface is solved with fixed meshes.By using this model,the melt pool configuration,temperature field within the workpiece,and flow field in the melt pool are computed for the GTA welding process of stainless steel.It is found that the melt pool configuration obtained is consistent with that of practically welded.