Capability of weld seam improvement techniques for the fatigue strength optimization of welded high strength steels

Abstract Fatigue-loaded welded constructions are mainly designed according to the experimental results of low-strength steels, although great knowledge about the properties of modern high-strength steels is available. Due to the increasing notch sensitivity with increasing yield strength, the applicable load amplitudes are mostly independent of the steel grade. This paper presents various options for exploiting the potential of high-strength steels subjected to cyclic loads. Therefore, different post-weld treatments are investigated. The calculated fatigue strength is thereby based on IIW guidelines. The results indicate a high potential for an increase in fatigue strength up to a calculated FAT class with a variable slope of FAT392. This is considerably higher than the currently valid base metal level of FAT160.