Characteristics of Filler Wire Laser Welding of Low Carbon Low Silicon Non-oriented Electrical Steel

The filler wire laser welding of low carbon low silicon non-oriented electrical steel was performed using 15 kW CO2 laser welding equipment with different welding parameters.The tensile testing,microhardness measurement and microstructure analysis of the welded specimen were carried out.The rules of the weld microstructure and properties with different weld linear energies were obtained.The results show that with reducing linear energy,the weld microstructure varies from block ferrite to needle-like ferrite and granular bainite,and finally M-A constituent with obvious orientation could be found in the weld seam.The penetration of the electric steel was reduced,and it is easier for M-A constituent to form because of the action of silicon in the base metal.Reducing the silicon content in the welding wire may hamper the forming of M-A constituent,raise the toughness of the weld seam and elevate the quality of filler wire laser welding of electric steel.