Development of Properties of P/M Austenitic Stainless Steels by Nitrogen Infusion

Abstract

Properties of nitrogen alloyed P/M austenitic stainless steels manufactured by Hot Isostatic Pressing (HIP) of gas atomized powders were studied. Nitrogen contents beyond the solubility limit of nitrogen in the melt were obtained by solid state nitriding in a fluidized bed furnace. As a disadvantage of the fluidized bed nitriding, the oxygen contents in the powder and the final product increased. Nitrogen alloying increases the strength level, as well as the corrosion and wear resistance of P/M austenitic stainless steels. Nitride precipitation is detrimental to corrosion resistance and ductility, but beneficial to yield strength and wear resistance.