Some theoretical aspects on designing nickel free high nitrogen austenitic stainless steels

Abstract

Nickel free high nitrogen austenitic stainless steel design calls for proper choice of alloying constituents that enhances nitrogen solubility and retention of the same after alloying. The nitrogen alloyed should be adequate enough to give a single phase austenitic matrix along with other alloying elemental constituents. The various studies that evaluated these aspects show certain inconsistencies. Certain empirical formulations have been evolved in this study by analyzing all various published data. The formulae obtained, enables choice of alloying elemental composition to get desired microstructure and strength in the solution annealed condition. The various inadequacies that exists in the data used for assessing nitrogen solubility calls for caution when they are applied to actual nitrogen steel production process conditions.