Laser Welding Deformation Control of STS304 Cylindrical Steel Sheet Structure

Abstract

Deformation that occurs during girth welding and seam welding of large-diameter STS304 thin plate structure changes the shape of the structure and affects the manufacturing of the next process. In order to control this deformation, the welding deformation generated during girth and seam laser welding was controlled by generating the relationship between the neutral axis and the welding position and initial tensile stress by the tensile force method. The deformation that occurs during girth welding is caused by angular distortion, and the amount of the deformation is affected by the neutral axis and the position of the weld. By changing the position of the welding part, welding deformation by up to 50% has been reduced. Deformation generated during seam welding caused by angular distortion and longitudinal bending deformation created an initial tensile residual stress in the weld, and the deformation was controlled by minimizing the constraint by welding heat stress generated during welding. At this time, when the magnitude of the initial tensile stress due to the external load increased to 50% of the yield stress of the base metal, the final deformation appeared close to zero. Key words: Thermal elastic-plastic analysis, STS304, Laser welding deformation, Initial stress, Elastic pre-straining method