Application of laser welding to STS301L side structure of railway vehicles(I) - vertical incidence welding conditions for laser beam based on multiple regression analysis

Abstract

In this study, the vertical incidence welding conditions of laser welding was tested to improve the finished appearance by replacing the resistance spot welding method applied to the side block of the STS301L side structure of railway vehicles. Continuous wave Nd:YAG laser welding using argon shielding gas was applied to a lap joint using STS301L-1/2H stainless steel as a base material in experiments. Multiple regression analyses were performed with 14 kinds of sample welding experimental data, and a regression equation was derived that was suitable for selecting the vertical incidence welding conditions for the laser beam. An accuracy of approximately 98 % was obtained for the predicted value. Two conditions were selected for the regression equation, and the welding quality was verified using macro-tests and tensile shear tests. A laser power of 1920 W and welding speed of 270 cm/min were selected as the optimal conditions. © 2023, The Korean Society of Mechanical Engineers and Springer-Verlag GmbH Germany, part of Springer Nature.