Abstract: A method for ultrasonic impact machining (UIM) of straight or curved surfaces using a tool with a free rod-shaped indenter to execute ultrasonic impacts by an action of the tool natural vibrations and ultrasonic transducer resonance oscillations, with goals of strengthening a surface, increasing hardness, creating compressive stresses, and/or modifying surface structure based upon diminishing mosaic blocks up to an amorphous structure is disclosed. These physical effects result in at least one of increased abrasive damage resistance, increased contact injury resistance, increased corrosive damage resistance under stress, increased endurance, increased resistance to fatigue and dynamic fractures, creation of conditions for forming prescribed physical and mechanical properties in the surface. The method provides machining of external and internal faces of straight and curved shapes, and provides indenter axis orientation perpendicular to a workpiece surface at every point of mechanical trajectory of the tool.

Abstract: A method for improving the performance of sections of rails joined together by welding by reworking welded joints utilizing an ultrasonic impact treatment (UIT) process either before welding, during welding, after welding or during repairs of used rails, including treatment of a joint, around a joint and/or length of a rail, in order to increasing fatigue life and/or other properties of welded rail sections is disclosed. The method provides reduction of stress defects and redistribution of internal stress patterns in the vicinity of weld seams of rails. The UIT provides periodic pulse energy impact treatment with surfaces in welded rails to induce internal compression waves inducing a metal plasticity state in the vicinity of the weld seam of the rail or in the rail itself.