Stainless steel-making

In the process of steel making, the liquid steel which is produced from low cost material must be refined, and it require that making the efficient continuous casting into continuous casting slabs with high-temperature processing property. Ex-federal Germany developed the Vacuum Oxygen Decarburization in 1967 and the United America developed the Argon Oxygen Decarburization in 1968. These two methods are main technologies nowadays. In a word, we usually use Electric Arc Furnace, EAF, which melt stainless steel scrap iron, low-carbon scrap iron and iron ore together, then decarburize in AOD and deoxidize by Ai/Si. In these processing, blowing Ar is to avoid that Cr is oxygenized into residues. For 100 tons, the chemical composition Carbon usually get to 0.30% ~ 0.35%, sulfur get to 0.003%~ 0.005%. At last, the continuing decarburization by VOD finally get the required liquid steel. The Carbon composition is 0.01% ~0.03%. And the recovery ratio is about 98%, nickel and molybdenum retain in the liquid steel.