Exploring the electrodes alignment and mushrooming effects on weld geometry of dissimilar steels during the spot welding process

Abstract

The class two of RWMA electrode caps has very common application-purpose for the welding of steels and withstand for high thermal application on wrought cast. It has been experimentally used to weld carbon and stainless steels up to 900 weld attempts using AC waveform, C-type JPC 75 kVA, Japanese made spot welder. So the electrode alignments and resulting mushrooming effects are finally analysed in this research as well as the weld geometry of dissimilar (carbon and stainless) steels. When considering such weld joints, the heat imbalances are very interesting factors on spot welding research and therefore I have simulated the dissimilar weld joints using Ansys 14. Initially, it was simulated and later those results are compared with real welded samples. The common welded regions such as: fusion zones, heat affected zones, heat extended zones and base metals are all well-noticed for carbon steel sides but not for stainless steel sides. Besides, the electrode mushrooming effect on both sides of electrodes are not parallel deterioration and it has some demerits on internal structure indeed. Some of the dissimilar welded samples and electrode caps are eventually underwent metallurgical test to identify the improper alignment.