LAUSR

Abstract This paper deals with laser-arc hybrid welding of high nitrogen steel with 1.2 mm diameter filler wire. The effect of nitrogen content in the weld on the microstructure and properties was analyzed. Results show that as the nitrogen content in the weld increases, ferrite growth is inhibited and the average hardness of the weld increases. As the nitrogen content in the weld increases, the tensile strength and elongation of the joints first increase and then decrease. The tensile strength and elongation of the joint with a nitrogen content of 0.52% reach a maximum, which are 928.9 MPa and 7.3%, respectively. As the nitrogen content in the weld increases, the impact energy of the joints first increase and then decrease. The impact energy of the joint with a nitrogen content of 0.52% has the highest impact energy of 51.7 J. Increasing nitrogen content can enhance the solution strengthening effect, but higher nitrogen content will cause nitrogen pores in the weld to form.