Residual stresses can distort mechanical parts and shorten their lifespan. While heat treatment is a common method for stress reduction, limitations such as furnace size and processing time can make it impractical in some cases. Magnetic stress relief offers an alternative approach. This research investigates the relief of residual stress induced by laser welding in 430 steel using the alternating magnetic stress relief method. Applying excitation frequencies near the component's natural frequencies improves the effectiveness of stress relief. Four steel strips were laser-cut to size, annealed, and then laser-welded. Three of the welded strips underwent alternating magnetic stress relief, while the fourth served as an untreated control. All samples were then sectioned via wire cutting at identical distances from the weld line. Nanoindentation was performed on each sample to estimate the residual stress before and after magnetic treatment. Analyzing the force-displacement curves from the nanoindentation test reveals that the alternating magnetic field method significantly reduces residual stresses. The reduction ranges from 38% near the weld line to 84% in the far-field areas. The results demonstrate that high-frequency magnetic stress relief effectively reduces residual stresses despite utilizing relatively simple and inexpensive equipment. While the method demonstrates significant stress reduction, the study is limited to a single material (430 steel) and a specific specimen geometry. Validation through complementary measurement techniques is recommended for future work.
