||Cavitation wear resistance, of four different nickel-based alloy during the incubation period was investigated with the use of stream-impact device and results are presented in this paper. Four nickel alloys with excellent resistance corrosion very high corrosion resistance and very good mechanical properties were selected for the tests: Monel 400, Inconel 600, Incoloy 800H and Hasteloy C22. Nickel alloys examined for the period of 600 minutes. Mechanism
of formation and destruction of the surface layer under working liquid influence is described.
It was noticed, that first microcracks are formed on the grain boundaries, especially in the triple contact points. Effects of plastic strain were also noted on the surface of samples as a uplifting and collapsing in boundary area. It was stated, that among nickel alloys examined, a better resistance to cavitational erosion in initial period of cavitation damage has the alloys: Hasteloy C22 and Incoloy 800H.