Assessment of the Effect of Residual Stresses Arising in the HAZ of Welds on the Fatigue Life of S700MC Steel

Fine-grained steels, which belong to the HSLA (High-Strength Low-Alloy) group of are increasingly used for parts statically and dynamically loaded constructions. Due thermal effect welding, combined with inherent stiffness clamping part, residual stresses generated in HAZ (heat-affected zone) affect fatigue life sub-weld entire construction. In this article, a specific temperature cycle measured during welding is used, which, together defined stiffness, produces shape value sample. Subsequently, these on change S–N curve compared annealed material, assessed. Temperature cycles were applied using Gleeble 3500 analyzed by X-ray diffraction (XRD). It was found that decreased strength 33% material. further annealing reduce stresses, it possible restore S700MC steel original base