ナゲット径の異なる高張力鋼板抵抗スポット溶接継手の疲労挙動

抄録

Spot welds are fabricated using high strength and low carbon steel sheets with three different strength levels by a resistance spot welding (RSW) procedure. The nugget sizes are changed by controlling welding process parameters. Subsequently, tensile-shear fatigue tests are conducted to investigate the effects of strength levels of steels and nugget sizes on the fatigue behavior of welds. The fatigue strengths of the welds with 4√t nugget size are nearly the same irrespective of strength levels of steels, because fatigue crack propagation life is dominant in total fatigue life. In the welds with 3√t nugget size, the steel with higher strength exhibits lower joint fatigue strength.