Q235与 304L异种钢角焊缝 GTAW电弧能量分配规律研究

针对Q235低碳钢与304L不锈钢的异种钢角焊缝两侧母材热物性参数的差异以及电弧热量分配不正确,导致的焊后热应力集中,易发生裂纹等焊接质量问题,本文开展了GTAW电弧能量分配规律的研究。采用多物理场软件COMSOL Multiphysics,建立了异种钢角焊缝直流脉冲GTAW电弧瞬态二维非对称模型,并对Q235和304L角焊缝焊接时电弧的温度场、电磁场、流场和不同焊枪角度下的电弧能量分布进行了耦合计算。解释了异种钢焊接时,由于材料导磁性能差异造成的电弧磁偏吹现象,以及焊接电流对电弧磁偏吹的影响规律,获得了不同焊枪角度条件下电弧热流密度在焊缝两侧的分布规律:在焊枪角度为10°时,焊缝两侧能量分布基本相等。利用焊枪偏转调控异种钢焊缝两侧的电弧能量输入,建立了焊缝两侧分配能量流与焊枪偏转角度的回归方程,通过焊接试验对模拟结果进行了验证,在焊枪偏转角度为10°时获得了较好的焊接质量。

Study on energy distribution law of GTAW arc in fillet welds of Q235 and 304L dissimilar steels

In view of the differences between the thermophysical property parameters of base metal on both sides of dissimilar steel welds of Q235 low-carbon steel and 304L stainless steel, as well as the incorrectness of arc heat distribution, which results in the problems of post-welding thermal stress concentration, prone to crack and other welding defects, the energy distribution law of GTAW arc was investigated. A two-dimensional asymmetric model of dc-pulse GTAW arc transient in fillet welds of dissimilar steels was established by COMSOL Multiphysics. The temperature field, electromagnetic field, flow field, and arc energy distribution at different welding gun angles of Q235 and 304L fillet welds were coupled. The arc magnetic deviation phenomenon caused by the difference of magnetic conductivity of materials during welding of dissimilar steels and the influence of welding current on the arc magnetic deviation phenomenon were explained. The distribution law of arc heat flux on both sides of welds under different welding gun angles was obtained. When the welding gun angle was 10°, the energy distribution on both sides of welds was basically equal. The arc energy input on both sides of dissimilar steel welds was controlled by welding gun deflection, and the regression equation between energy flow on both sides of welds and welding gun deflection angle was established. The simulation results were verified by welding test, which provides technical support for energy control on both sides of dissimilar steel welds.