Effect of pre-heat treatment and welding parameters on microstructure and mechanical properties of 6061/316L FSLW joint

The effect of pre-heat treatment for 316L stainless steel and welding parameters on microstructure and mechanical properties of 6061 aluminium alloy / 316L steel FSLW joint were investigated. Softening 316L properly before welding is helpful to improve the fluidity of metals in the nugget zone of 6061/316L FSLW joint. The findings indicated that the FSLW joint exhibited a peak shear load of 7185N with a preheating process of 316L at 800°C for 1 h and the rotational speed, the welding speed and the plunge depth are 800 rpm, 100 mm/min and 0 mm, respectively. The thickness of the IMC layer and the hardness distribution of the weld nugget zone can be optimized to significantly improve the property of the FSLW joint through the adjustments of pre-weld heating treatment for 316L and welding parameters.