Effects of Diffusible Hydrogen on Fatigue Life of Spot Welds in High-tensile-strength Steel Sheets

Spot-welded advanced high-strength steel (AHSS) sheets are used to decrease car body weight and enhance crashworthiness simultaneously. Such welds susceptible hydrogen embrittlement, but research in this area is limited. We have evaluated the embrittlement properties of spot fabricated with AHSS clarified dependence diffusible content tensile rate on shear strength. However, performance must be not only by static testing such as tests also dynamic fatigue testing. Herein, we investigated effects their life via tensile–shear under cathodic charging. The number cycles failure endurance limit decreased content. constant amplitude-loading frequency declined. intergranular cracking more likely occurs amount increases decreases. These results explained accumulation crack growth behavior caused mechanism for hydrogen-enhanced local plasticity enhancement strain-induced generation vacancies mechanism. Furthermore, correlation between was investigated, relationship strength good agreement obtained from slow