Influence of high frequency peening on fatigue of high-strength steels

Abstract

Post weld treatment methods like the high frequency peening technology (HFP) increase the fatigue strength in the finite lifetime and even in the high-cycle fatigue region. In this study the fatigue improvement of HFP on three different weld seam geometries made of thin-walled high-strength steel is shown. Extensive experimental fatigue tests are investigated to gain a comparison of the fatigue behavior of the base material, as welded and post treated condition. Different fatigue approaches are applied including the nominal stress method and the local notch stress concept. For the HFP treated condition an obtained key result is that the fatigue strength enhancement at joined components increases with a higher stress concentration factor at the post treated weld toe.

Keywords

• fatigue behavior
• welded joints
• high-strength steel
• local fatigue assessment
• post weld treatment
• high frequency peening