Remanufacturing of Surface-Hardened Steel Components by Ultrasonic Surface Modification

This project seeks to develop practical repair techniques to recover nominal ‘as-new’ fatigue life in used or worn surface-hardened steel components by i) forging closed preexisting microcracks, ii) introducing beneficial compressive residual stresses (CRS) deeper than conventional shot peening, and iii) generating a nanocrystalline microstructure at the surface. Surface repairs based on UIT (a form of high-frequency needle peening) will be developed for a range of usage-induced damage conditions that are commonly found in these components, but for which there is a lack of practical repair methods.