The evaluation of laser weldability of the third-generation advanced high strength steel

Abstract

To meet the demands of vehicular safety and greenhouse gas emission reduction, the automotive industry is increasingly using advanced high strength steels (AHSS) in the production of the components. With the development of the new generation of AHSS, it is essential to study their behavior towards manufacturing processes used in the automotive industry. For this purpose, the welding capability of newly developed third-generation Gen3 980T steel was investigated using the Nd:YAG (Neodymium:Yittrium Aluminum Garnet) laser-welding with different parameter conditions. The analysis was made by uniaxial tensile tests, micro-hardness, Scanning Electron Microscopy (SEM) and X-Ray Diffraction (XRD). The criteria used to evaluate the quality of the weld were the distance between the fracture and the weld bead and the surface finish. A relationship between the quality of the weld and the energy density was observed, expressed by a partial penetration for values below the optimal, and by irregularities in the weld bead and a high number of spatters for the values above the optimal.