Ultrasonic impact treatment as a way of increasing welded connections strength

Investigations of surface hardening of welded joints for various types of steel have been elongated with the help of ultrasonic impact treatment, replacing thermal one in removing the residual tensile stress. Thermal one cannot be used always because it is expensive and impossible in important large-sized welded productions (bridges, heavy haulers, etc.) working under variable loading. Ultrasonic impact treatment coupled with ultrasonic method of assessment of the residual stress level allows processing of welded constructions by all sizes under controlled conditions. Research of structure and properties of welded joints permit to recommend the ultrasonic impact treatment as alternative to thermal one. The equipment required is offered in this paper.