Effect of laser-GTAW hybrid welding heat input on the performance of Mg/Steel butt joint

show that laser-GTAW hybrid welding with filling wire can be used to combine high-performance joints and Mg/steel dissimilar metals during butt assembly. The maximum average tensile fracture load of the joints can reach up to 3265 N (the load equal to that of steel base metal). The tensile load of the joints decreases with the decrease in heat input. A reaction layer is formed on the welding interface enriched with Al and Mn elements. The morphology of Mg/steel joint and the thickness of interface transition layer are the key factors affecting the properties and fracture mechanism of the welded joint. With the decrease in heat input, the Mg/steel butt joints had three fracture modes, including the fracture on the base metal of steel, Mg weld seam, and Mg/steel interface.