프로젝션용접에서 돌기 크기에 따른 용접 특성

Abstract

Purpose: Projection welding is a resistance welding method in which materials are welded using the heat generated by passing an electric current to the projection of the metal base material. In this study, the characteristics of the projection welding quality were considered in terms of the projection size for the strut of a car rear suspension module. Methods: Five welded specimens with a projection size ranging from 0.4 mm to 1.4 mm in intervals of 0.2 mm were prepared, and the corresponding surface appearance, tensile strength, and nugget diameter were compared. Results: For a projection size of 0.8 mm or higher, the tensile strength satisfies all the specifications, and the projection height of 1.2 mm corresponds to the highest quality. For a projection size of 0.6 mm or higher, the nugget diameter satisfies the specifications. However, the projection size of 1.2 mm exhibits a large standard deviation. Conclusion: Considering the obtained results, the projection size and lower specification of the nugget diameter are recommended to be increased to 1.2 mm and 6.0 mm, respectively.