The Influence of Ultrasonic Impact Treatment on Fatigue Behaviour of Welded Joints in High-strength Steel

The unabated growth of the steel industry and progressively increasing operating loads on metal structures generate a need for a search for optimum engineering solutions to improve the loadcarrying capacity and reduce metal consumption. One way of resolving this problem is to utilise high-strength steels. It is common knowledge however that the improvement of the steel strength is accompanied by the reduction in fatigue resistance of welded joints down to mid-strength steels and below. This paper presents the results of the research aiming at the evaluation of the influence of various post-weld fatigue improvement techniques on the fatigue limit and life of welded joints in midand high-strength steels. It has been demonstrated that the UIT method is the most efficient fatigue improvement technique that at the same time makes it possible to take advantage of high-strength steels in fabrication of welded structures operating under variable loading. International Institute of Welding FRENCH DELEGATION AMERICAN DELEGATION RUSSIAN DELEGATION Institut International de la Soudure DÉLÉGATION FRANÇAISE DÉLÉGATION AMERICA DÉLÉGATION RUSSIE