PROCESS FOR PRODUCING HIGH-PURITY STEEL BY REDUCED PRESSURE TREATMENT

摘要

PURPOSE: Provided is a high-purity steel which has so improved a purity of product and decreased a low-fault generation rate by adding alloy such as FeTiH to reduce amount of non-metallic inclusion. CONSTITUTION: A process comprises the steps of: performing decarboxylation by reduced pressure or vacuum refining to adjust 6-20 wt% of total content of Fe+MnO and 0.8-2.5 of (% CaO)/(%Al203) value in a furnace slag and a ladle slag during the delivery of steel; performing deoxidization using aluminum or silicon under reduced pressure of the steel; agitating the steel; and injecting 0.01-0.5kg/ton steel of FeTiH2. The process can be useful to manufacture of the cooling limit low-carbon steel.