Steel strip continuous mfr. - by reducing iron oxide pellets to sponge iron pellets which are hot rolled

摘要

A l ong workpiece or strip is made from pellets contg. purified iron oxide, which may be partly reduced, bonded by an organic binder. Pellets are reduced by gas to form sponge pellets which are hot rolled in a rolling mill to make strip. Fe oxide pellets are of sizes 1-10mm.; 1.5-15mm.; or 3-7mm.; and the iron oxide pref. contains min. 98% Fe+ FeOx. Gas is pref. H2+CO used at 950-1200 degrees C and the sponge pellets are rolled at 900-1150 degrees C esp. in a non-oxidising atmos. Alloying powder(s) may be added to the sponge pellets before rolling; and/or pellets may be exposed to a carburising atmos. before rolling. Pellets are pref. rolled into steel strip. Steel strip is directly made from iron oxide pellets.