双面电弧焊接的传热模型

将等离子焊接(PAW)电弧和钨极氩弧焊(TIG)电弧串接,相对作用于工件的正反面形成双面电弧焊接(DSAW)系统,可以引导焊接电流沿工件厚度方向流过小孔,补偿等离子电弧穿透工件时消耗的能量,以有效地提高等离子弧的穿透能力.综合考虑影响双面电弧焊接正反面熔池几何形状的力学因素,建立了熔池表面变形的控制方程,以此为基础并采用帖体曲线坐标系建立了DSAW焊接传热的数学模型,分析了DSAW,PAW焊接传热的差异,从传热的角度解释了DSAW焊接熔深增加的原因.焊接工艺实验表明,计算结果与实测结果吻合良好.关键词：双面电弧焊接(DSAW)传热模型熔池表面变形模型

Heat transfer modeling of double-side arc welding

If a plasma arc and a TIG arc are connected in serial and with the plasma arc placed on the obverse side and the TIG arc on the opposite side of the workpiece,a special double-side arc welding (DSAW) system will be formed,in which the PAW current is forced to flow through the keyhole along the thickness direction so as to compensate the energy consumed for melting the workpiece and improve the penetration capacity of the PAW arc.By considering the mechanics factors which influence the DSAW pool geometric shape,the control equations of the pool surface deformation are derived,and the mathematics mode for DSAW heat transfer is established by using boundary-fitted non-orthogonal coordinate systems.With this model,the difference between DSAW and PAW heat transfer is analyzed and the reason for the increase of DSAW penetration is explained from the point of heat transfer.The welding process experiments show that calculated results are in good agreement with measured ones.