Arc welding is commonly applied to high-strength steel for buildings (H-SA700). However, the heat-affected zones of H-SA700 often become soft and the yield stress decreases compared to that of the base metal owing to the large heat input of arc welding. In this study, laser welding was applied to H-SA700. The residual stress, hardness, mechanical property and fracture toughness of H-SA700 after laser welding were examined and the results were compared with those of arc welding. As a result, the softened area of H-SA700 welded using laser welding was considerably smaller than that obtained using arc welding, and the yield stress was the same as that of the base metal. Fracture pass deviation (FPD) was observed in the Charpy impact test.
