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 But if calcium can be added under a higher pressure than the vapor pressure to prevent its boiling and in an inert gas atmosphere to protect its oxidation, it will work as a strong deoxidizer and desulfurizer, and the calcium addition will become an economically cheap method, since it saves the refining time.In the present study, we produced high N-20Cr-lONi stainless steels with nitrogen contents up to 0.8 wto/o by a high pressure induction furnace, and investigated the effectiveness of calcium addition for the deoxidation and desulfurization in the process. 2.Experimental Method Fig. I

Conversion of Mill Scale Waste into Valuable Products via Carbothermic Reduction

“…It can be also noticed that, at the same slag basicity, the dotted line (fluxing material includes CaSi) represents lower sulphur content comparing to the solid line (fluxing material does not include CaSi). This behavior could be attributed to the powerful effect of CaSi as deoxidizing agent results in low activity of oxygen in the melt leading to appropriate conditions for the removal of the sulphur and desulphurization of the metal [13].…”

Change of Spinel in High Ca Treament at 38CrMoAl Steel

“…Take into account that following reaction occur during Ca treatment 4), ( 5) and ( 6), it can be deduced that According to the binary phase diagram of CaO-Al 2 O 3 , the main products at higher CaO are C 12 A 7 , C 3 A and CaO. Table 3 shows the activities of CaO and Al 2 O 3 in the literature [25][26][27] and calculated by Factsage 8.1 in this study.…”

Determination of Equilibrium Constant of Calcium Oxidation by Slag-Metal Equilibrium Distribution Method

“…For the equilibrium constant of "O = 1/2O 2(g) ", because the solved oxygen content in the titanium particles is reported in the paper, that is determined as shown in Table 1 by the relation reported by Ono et al 44) S. Kobayashi et al, 48) Q. Han et al, 37) T. Kimura and H. Suito, 49) H. Fujiwara et al, 50) H. Ohta and H. Suito 51) and H. Itoh et al 52) performed the slag/metal equilibrium distribution method for a molten iron. K. Mineura et al 53) and H. Ohta and H. Suito 54) used a stainless-steel (FeNiCr alloy) for their studies. Among these studies, Q. Han et al 37) used a metallic crucible made of molybdenum, while other researchers used ceramic crucibles.…”