Abstract
Some effects of welding conditions on the strength of spot welded joints were studied. Spot welds under various welding conditions were performed on SPC-1 (cold rolled carbon steel sheets). Static tensile and bending fatigue tests were carried out, and the following results were obtained:
(1) A dominant facto: on bending fatigue strength was different from that of static tensile fracture strength. The static tensile strength increased with nugget diameter. The bending fatigue strength changed with HAZ angle (θ), which is the angle between the heat-affected zone and the plate surface.
(2) It was found that the fatigue crack propagated along the parallel direction to heat-affected zone.
(3) The welding condition of R.W.M.A. class A gave the maximum static tensile strength but the minimum for bending fatigue strength.
