Specifics of Creating Joints from Modern Boron-Microalloyed High-Strength Steels Utilizing Laser, Contact Spot, as Well as Argon-Arc Spot Welding Technologies

In this study, an analysis of current welding technologies for new high-strength low-alloyed AHSS sheet steels is presented. Over the course of it, a series of welded joints of sheet metal with a thickness of 1.2 mm made of CR1000Y1370T-CH steel (composition: 0.23% C, 2% Si, 3% Mn, 0.015–2% Al, 1% Cr + Mo, 0.15% Ti + Nb, 0.2% Cu) by Voelstalpine (Austria) is inves-tigated. The joints are produced using laser, spot, and argon-arc spot welding under specified conditions. High-quality weld joints are obtained through laser welding with the formation of a dispersed ferrite–bainite structure with an acceptable hardness level (up to 4000 MPa) without martensitic-type structures and zinc evaporation from the sheet coating along the entire length of the welded joint. As discovered, due to delamination and remnants of zinc coating, it is not possible to achieve a high quality of weld joints while using spot welding, as well as argon-arc spot welding. The selected welding conditions for these technologies are found to be ineffective and require fur-ther refinement.