Effect of laser welding on microstructure and mechanical behaviour of dual phase 600 steel sheets

• DOI: 10.1016/j.heliyon.2021.e08601
• Publication Date: 2021-12-16T01:45:19Z
• Authors: Vinicius Machado ...; Raquel Alvim de F...; Sheila Medeiros d...; Rafael Humberto M...; Milton Sergio Fer...
• Keywords: Dual-phase steel; Weld line; Ductility (Earth science); Butt welding; Fusion welding

Dual Phase steels are one of the most used advanced high-strength materials in industry, due to its combination a ductile ferritic matrix and disperse hard martensite islands, which provide outstanding mechanical properties for components be cold stamped. This work investigated fiber laser welding applicability 600 1.6 mm thick steel sheets, evaluating potential impacts on material industrial applications. A first set bead-on-plate welds was generated define best parameters subsequent tests. second prepared, consisting butt joints welded optimized condition. Weld microstructure characterized as 100% martensitic at fusion zone (FZ), with growing fractions ferrite Heat Affected Zone (HAZ) moves away from line. Hardness is around 60% higher FZ than BM, being maximum supercritical HAZ highly refined softening not observed. Tensile Erichsen cupping tests presented similar strength results between non-welded specimens, slight ductility reduction. Finally, numeric simulations based Finite Element Analysis were carried out estimate temperature evolution, phase proportions, residual stresses distortion levels, achieving excellent agreement experimental results.