Deoxidation and Desulfurization of Pressurized Liquid High Nitrogen Stainless Steels with Calcium

Abstract

High N-20Cr-10Ni stainless steels in the range of 0.25-0.7%N were melted by a high pressure induction furnace. These molten metals were deoxidized and desulfurized by calcium after pre-deoxidation by aluminum. It is concluded that the calcium addition is one of the most promising methods for desulfurization and deoxidation in the production of high nitrogen stainless steel by high pressure melting method. The interaction parameters e_O^Ca and e_S^Ca are obtained according to the Gustafsson's method, of which values are nearly equal to those proposed by Gustafsson. The equilibrium contents among Ca, S, O and Al components are computed using the apparent equilibrium constants and the interaction parameters obtained in the present study. The influence of aluminum on the calcium deoxidation and desulfurization is large, and therefore, pre-deoxidation by aluminum is important for the deoxidizing and desulfurizing process of calcium.