Research on fatigue behavior of the flash welded joint enhanced by ultrasonic peening treatment

摘要

The flash welded joint of U75V steel has been widely used in high-speed railway. Considering the fact that fatigue failure is the main failure mode of high-speed railway, ultrasonic peening treatment (UPT) was used to improve the fatigue performance of the flash welded joint Micro-structure, hardness, wear resistance, corrosion resistance and fatigue fracture mechanism of the flash welded joint before and after UPT were analyzed in detail. Results show that nanocrystals form on the surface of the welded joint after UPT. Fatigue life, wear resistance and corrosion resistance of the welded joint were improved for the surface strengthening caused by UPT.