Otimização da resistência de tração de pontos soldados por corrente elétrica – processo solda ponto de uma indústria do polo de duas rodas

Abstract

Resistance spot welding is the most used process in the assembly of structures, such as: automobiles, trucks, planes, train cars, etc. As an example, in the assembly of car bodies, an average of 5,000 welding points are required. These facts show the importance of this welding process in bodywork assembly due to its efficiency, speed and ease of automation. In addition, resistance spot welding behavior is extremely important for the quality of the entire welded structure. The present work will be focused on the evaluation and study of optimization in the spot welding process on the pole of two wheels, with main focus on the mechanical tensile strength of the welded spots, starting from a statistical method of factorial planning, using the variables that directly influence in the traction values; Then, quality tests were performed to validate the proposed test. The optimization process it was possible to verify that applying a current of 7.5 kA, welding time of 14 milliseconds and electrode force of 189 kgf, it was possible to reach 4667.19 N of spot welding resistance, a gain of 345 N in relative to current resistance. The points of relationship between what we currently have versus what will be proposed were analyzed. Parameter validation tests will be based on macrography tests and mechanical strength with tensile testing. The results showed that the welding in the factors Current and Welding Force presented better mechanical resistance compared with the welding factor Current x Welding Time. The tests proposed in this work will be reported in a document at the company to table and map the parameters in case there are variations in the spot welding process in the future. All solder points with the optimized parameters found by the method presented in this work were approved according to the standard.