THE EFFECTS OF POST-WELD COLD WORKING PROCESSES ON THE FATIGUE STRENGTH OF LOW CARBON STEEL RESISTANCE SPOT WELDS

摘要

The investigation on the use of a post-weld cold working process to improve fatigue strength of low carbon steel resistance spot welds is presented. The cold working process generates uniform and consistent large zones of compressive residual stresses in resistance spot-welded low carbon steel structures using a specially designed indentation device. The effect of the indentation process parameters on the mechanical properties of the resistance spot-weld was investigated. Comparisons of the mechanical properties and qualitative results between the as-resistance spot-welded specimens and the post-weld cold worked resistance spot-welded specimens have been made in this investigation. Fatigue testing was also conducted to evaluate the effect of post-weld cold working process on the fatigue characteristics of resistance spot welds. Preliminary results showed that a significant improvement in the fatigue endurance limit has been achieved through the post-weld cold working process.