Effects of welding time and welding current to weld nugget and shear load on electrical resistance spot welding of cold rolled sheet for body construction

In this study, the electric resistance spot welding process was applied to cold rolled sheet used in automotive industry for body construction. Resistance spot welding parameter such as, electrode form, electrode material, and electrode force were stayed constant. This experiment uses different welding time and welding current to identify the optimum welding parameters for maximum joint strength. By using 1, 2, and 3 kA welding current and 4, 6, and 8 cycles welding times 0.8 mm, sheets were spot welded to prepare samples. These spot-welded joints were tested with uniaxial tensile test in laboratory to identify shear strength from spot-welded joint. This experiment is not only to identify shear load from the result of uniaxial tensile test but also to observe the size of weld nugget. Weld nugget can detect the quality of spot-welded joint with its size to prevent the expulsion and get the acceptable nugget diameter in that process. This experiment shows the optimum welding parameters that can be used in the automotive application especially in body construction.