Desulfurization behavior of Si-killed 316L stainless steel melt by CaO-SiO2-CaF2-Al2O3-MgO slag

Abstract

The desulfurization behavior of 316L stainless steel (STS316L) melt with the CaO-SiO2-CaF2-Al2O3-MgO slag was investigated with different CaO/SiO2 (=C/S) ratio and CaF2 content at 1873 K. As the C/S ratio increased, the sulfide capacity increased, whereas the sulfide capacity of the high C/S (=1.7) slag was not affected by CaF2 content. The overall mass transfer coefficient (k(O)) increased with C/S ratio, but was constant above a critical C/S value, and it was also constant across varied CaF2 content at relatively high C/S (=1.7) condition. Since the metal condition of the present study was constant, the change in k(O) was caused by slag phase mass transfer coefficient (k(s)) and sulfur distribution ratio (LS), which were affected by the physicochemical properties of the slag. Since desulfurization reaction requires consideration of both kinetic and thermodynamic factors, the 'log CS2- -log h' (where C(S2-& nbsp