GB628947A - Production of stainless steel - Google Patents

Abstract

A method of producing stainless steel containing 10 to 35 per cent chromium in an electric furnace comprises melting a charge of stainless steel scrap, iron oxide e.g. mill-scale and one or both members of the group high-carbon ferro-chrome and chrome ore with a fluxing agent rich in titanium oxide, and adding a non-carbonaceous reducing agent to the melt to reduce metallic iron and chromium from the oxides present in the slag. In a preferred method the fluxing agent contains at least one of the materials ilmenite, titamite and rutile, the non-carbonaceous reducing agent consists of at least one of the substances ferrosilicon, alsifer, or ferrochromesilicon, and lime is added with the said reducing agent or closely alternating with it. The original charge contains chrome ore and ilmenite, further amounts of both being added to the melt. The slag formed is finally removed and a non-carbonaceous finishing slag is made upon the bath, e.g., with a mixture of lime, ferrosilicon and a slag fluidifying ingredient, the manganese and silicon content of the steel being adjusted at the same time. If nickel is required in the composition of the steel, a major part of the necessary nickel is advantageously included in the charge and the remainder added later. Other alloying elements may be added in the furnace in the finishing stage or in the ladle, or at or near the end of the reducing period.