In-situ study on cavitation erosion behavior of super ferritic stainless steel

Revealing the cavitation erosion initiation and propagation in super ferritic stainless steels is important both scientifically and commercially. The initial microstructure of a Cr30Mo2 steel was observed through electron backscatter diffraction. Specimens were cavitation erosion tested for 2–12 h. The specimen surfaces were analyzed by scanning electron microscopy and optical profilometry. Cavitation erosion damage initiated at persistent slip bands and pits in grains with low Taylor factors. Material removal propagated along {100} planes and could continue across grain boundaries lower than ~30°. Grain boundaries with higher misorientation angles tend to retard cavitation erosion propagation. Finally, a mechanism was proposed for cavitation erosion in super ferritic stainless steel. •Damaged grains were those with low Taylor factor values.•Cavitation erosion damage initiated at persistent slip bands and pits.•Material removal propagated along {100} planes.•Grain boundaries higher than ~30° retarded damage.•A cavitation erosion mechanism was proposed.