Design of Stitch Welded Shape with Laser-ARC Hybrid Welding for Ultra-High Strength Steel

Several industries including the automotive industry have recently applied the process of welding high-strength steel for their requirements. Ultra-high-strength steel is harder than normal high strength steel; it is considerably much stronger and stiffer. In particular, ultra-high-strength steel (UHSS) can be formed in pieces that can be up to 10 to 15% thinner than normal steel without sacrificing strength, which enables weight reduction and improved fuel economy in automobiles. Furthermore, UHSS can be formed into complex shapes that can be welded into structural areas. This study is based on previous experiments and is aimed at establishing the maximum allowable vertical and longitudinal loads for stitch-welded ultra-high-strength steel in laser-arc hybrid welding. Research on the stress distribution and maximum allowable load and for stitch-welded ultra-high-strength steel is conducted via Solid-Works, a program that analyzes the stress of a virtual model. We determine that the maximum allowable load and stress distribution vary depending on the shape of the welded lap joint. The effects of the stress distribution and maximum allowable load on stitch-welded ultra-high-strength steel can be utilized as a standard for high energy welding of ultra-high-strength steel, and we can further predict fault regions in the stitch-welded.