Effect of He gas addition in Ar shielding gas on weld penetration of GMA welds of aluminium alloy. Improvement of weld penetration of GMA welds of aluminium alloy circular fillet joint

摘要

For MIG welding of aluminium alloy products, the start zone of overlap welds is susceptible to incomplete penetration weld defects; thus, it is necessary to determine the optimum welding conditions. There is little heat input during the commencement of welding at the weld start zone and it is extremely difficult to improve the state of penetration even though the welding conditions, such as welding current, voltage and speed are varied; however, it was confirmed that a sound penetration profile can be obtained, even at the overlap regions of the start and end zones, by adding 70 percent - 80 percent He gas to standard shielding Ar gas.