Abstract:The Cr-Ni-Mo-Cu alloy was used as build-up welding material to investigate cavitation corrosion by TIG surface welding and to compare with that of 304 stainless steel. Cavitation erosion test of Cr-Ni-Mo-Cu material as cladding layer was conducted on an ultrasonic vibratory apparatus under artificial sea water environment. The cavitation erosion rate was measured, and the surface morphology of cladding layer was observed by scanning electron microscopy(SEM). The results show that the cavitation resistant ability of Cr-Ni-Mo-Cu alloy is better than that of 304 stainless steel. The crack initiation tends to appear at grain boundaries of alloy during cavitation,and propagate before materials spalling. The work-hardening of alloy is achieved by the cavitation impact energy,and improves cavitation corrosion resistant ability of the cladding layer.