An Investigation of the Parameters Affecting the Quality of Resistance Spot Welds in Low Carbon Steel Sheets

Resistance spot welding is widely used in industry (especially in automobile manufacturing industries). There are approximately two to five thousand spot welds in the body of a car and the strength of the body is very muchdependent on the quality of these spot welds. Therefore, it is very important to use a proper technique for assuring the quality of spot welds. In this paper, the effect of welding parameters, such as electrical current, welding time,pressure, and the number of pulses on the weld tension-shear strength, surface hardness, and the hardness of welding center were studied. The design of experiments (DOE) technique was used for modeling the dependence of the input parameters on the output values. The results indicate that the weld strength is highly dependent on the welding time. The hardness of the weld center is also very sensitive to the changes in electrical current-thickness.