GB533703A - Improvements in or relating to the manufacture of steel or alloy steels - Google Patents

Abstract

533.703. Steels; alloy steels. SOC. D'ELECTROCHIMIE, D'ELECTRO-METALLURGIE ET DES ACIERIES ELECTRIQUES D'UGINE. March 16, 1939. No. 8478. Convention date, March 30, 1938. [Classes 72 and 82 (i)] In the production of steel at suitable casting temperature from molten steel obtained in a converter, the steel is first de-phosphorized either in the converter if it is a basic converter or in a ladle if the converter is either acid or basic, transferred to a basic converter not substantially contaminated by phosphorus containing slag and whose lining is not substantially impregnated with such slag and then acted upon in the basic converter with such a quantity of a reducing agent, the oxide of which has a high heat of formation, e.g. silicon, that by blowing for a very short time, e.g. 15 seconds to 1 minute, the combustion of the reducing agent evolves a quantity of heat which is sufficient to bring the steel to the high temperature necessary for casting either directly or after a subsequent de-oxidation. Manganese may be added before the short blowing which is effected in the presence of a slag rich in alumina and in alkaline earth and/or alkaline bases used in such quantity that after the blowing it is still basic. If excess of the reducing agent is added to the steel, the balance is incorporated in the steel. Alloying ingredients, such as chromium, nickel, molybdenum or vanadium may be introduced into the converter during the short blowing either in metallic form or in the form of oxidic compounds which are placed in the slag and reduced by the reducing agent. Specifications 404,300, 521,254 and 533,671 are referred to.