Characterization of stainless steels melted under high nitrogen pressure.
Rawers-JC; Dunning-JS; Asai-G; Reed-RP
Metall Trans, A, Phys Metall Mater Sci 1992 Jul; 23A:2061-2068
Mechanical properties of stainless steel increase with increasing nitrogen concentration. Currently, the maximum nitrogen concentration in commercial stainless steel is 0.8 Wt pct. In this study, type 304 and 316 stainless steels were melted and cooled in a hot-isostatic-pressure (hip) furnace using nitrogen as the pressurizing gas, producing alloys with nitrogen concentrations between 1 and 4 wt pct. These nitrogen levels exceeded the alloys' solubility limits, resulting in the formation of nitride precipitates with several different microstructures. A new phase diagram for high-nitrogen stainless steel alloys is proposed. Several properties of these nitrogen stainless steel alloys with chromium nitrides present were studied: tensile strength was proportional to the interstitial nitrogen concentration; hardness, wear, and elastic modules were proportional to the total nitrogen concentration.
OP; Journal Article
Metallurgical Transactions. A. Physical Metallurgy and Materials Science