AUSTENITIC STAINLESS STEEL WITH HIGH CAVITATION EROSION RESISTANCE

An austenitic stainless steel alloy showing a high cavitation erosion resistance making it particularly useful for the manufacture and/or repair of hydraulic machine components. The alloy consists essentially of from 8 to 30% by weight of Co; from 13 to 30% by weight of Cr; from 0.03 to 2.0% by weight of C; up to 0.3% by weight of N; up to 5.0% by weight of Si; up to 1.0% by weight of Ni; up to 2.0% by weight of Mo; and up to 16% by weight of Mn, the balance being substantially Fe, with the proviso that at least one of the following conditions is satisfied: the amount of C is higher than 0.3%, and/or the amount of Si is higher than 3.0% and/or the amount of Mn is higher than 9.0%. Moreover, the amounts of the above mentioned elements that are respectively known as ferrite formers (Cr, Mo, Si) and as austenite former (C, N, Co, Ni, Mn) and amongst said austenite and ferrite formers, the amount of each of these elements that are respectively known to increase and lower the stacking fault energy, are respectively selected and balanced so that at least 60% by weight of the alloy is, at ambient temperature, in a face centered cubic phase having a stacking fault energy low enough to show a fine deformation twinning under cavitation exposure or, alternatively, to make this face centered cubic phase transformable under cavitation exposure to a hexagonal close pack epsilon -phase and/or a alpha -martensitic phase showing such a fine deformation twinning.