Effects of Ni and Mn on the Cavitation Erosion Resistance of Fe-Cr-C-Ni/Mn Austenitic Alloys

The effects of Ni and Mn concentrations on the cavitation erosion behavior of Fe-12Cr-0.4C-xNi/Mn (x = 5, 7, and 10) alloys were investigated with respect to strain-induced gamma -> alpha' and gamma -> epsilon phase transformation. The cavitation erosion resistance of the Ni-added alloys decreased with increasing Ni concentration, whereas that of the Mn-added alloys improved with increasing Mn concentration. Also, the 7Mn-added alloy and 10Mn-added alloy, which additionally underwent the gamma -> epsilon phase transformation, had better resistance to cavitation erosion than the 5Mn-added alloy in which the gamma -> alpha' phase transformation occurs most actively. These behaviors were considered to be due to the fact that the strain-induced epsilon martensite absorbs the cavity collapse energy and prevents the damage by cavitation erosion more effectively than the strain-induced alpha' martensite.