不同脉冲、频率下的双丝匹配对焊缝的影响研究

目的 为提高双丝焊接质量，探究不同脉冲和频率下的双丝匹配对焊接质量的影响。方法 采用MIG焊接技术，在3 mm厚的不锈钢板上进行焊接实验，之后观察和分析焊缝表面形貌、电流波形、金相组织以及截面几何形状参数。结果 在同一频率下，前丝单脉冲组的熔深总是小于对应双脉冲组。随着双脉冲频率的增大，熔深、余高也随之增大，熔宽变化不大。结论 在频率为4 Hz时进行焊接能得到较为美观的焊缝。在双丝匹配时，前丝单脉冲会阻碍后丝双脉冲对基板的挖掘和熔滴对熔池的搅拌作用，且前后丝位置顺序对熔深、余高影响较大，对内部金相组织生长形态影响较小。

Influence of Double Wire Matching with Different Pulse and Frequency on Welds

The paper aims to improve the quality of the double wire welding and investigate the influence of matching different pulses and frequencies of the double wire on the welding quality. MIG welding technology was used to perform welding experiments on 3 mm thick stainless steel plates, after which the weld surface morphology, current waveform, metallographic organization and cross-sectional geometry parameters were observed and analyzed. At the same frequency, the depth of melt of the front wire single pulse group was always smaller than that of the corresponding double pulse group. As the frequency of the double pulse increased, the melt depth and the residual height also increased, with little change in the melt width. Welding at a frequency of 4 Hz results in a more aesthetically pleasing weld. In the double wire matching, the single pulse of the front wire will prevent the double pulse of the rear wire from digging into the substrate and the stirring effect of the molten droplet on the molten pool; and the order of the front and rear wire position has a greater influence on the melt depth and after height, and less on the internal metallurgical growth pattern.