Fatigue Behavior of Resistance Spot-Welded Unequal Sheet udThickness Austenitic Stainless Steel

摘要

This paper presents a comparative study on the fatigue strength of resistance spot-welded unequal and equal udsheet thickness austenitic stainless steel. Lap joints of 3.0-1.0 mm and 1.0-1.0 mm thick austenitic stainless steel udwere made using the same resistance spot welding schedule with current, weld time and electrode force of 4.7 udkA, 20 cycles and 6 kN respectively. The sinusoidal wave form with a constant stress amplitude was selected in udthe fatigue tests whereas the stress ratio and frequency used were 0.1 and 8 Hz respectively. Fatigue strength and udtensile-shear load bearing capacity of 3.0-1.0 mm joint were higher than that of 1.0-1.0 mm joint, although its udnugget diameter was smaller. The joint stiffness was the controlling factor of the fatigue strength of resistance udspot-welded unequal sheet thickness austenitic stainless steel.