RESISTANCE SPOT WELDING CHARACTERISTICS AND MECHANICAL PROPERTIES OF GALVANNEALED HSLA 350 STEEL

摘要

Galvannealed high strength low alloy steel 350 (GA HSLA350), because of its high strength-toweight ratio, is particularly attractive in transportation applications. The GA HSLA350 steel was spot welded at different welding currents to identify a suitable welding current giving good spot welds. Failure loads in tensile-shear increased with increasing welding current. As the nugget diameter increased, the failure mode changed from an interfacial to a button pullout mode. Cross-tension and microhardness tests were also carried out. The fusion zone microstructure was martensitic with a microhardness that was twice that of the base metal.