METHOD FOR OPERATING ELECTRIC ARC FURNACE AND FERRITIC STAINLESS STEELS MANUFACTURED THEREFROM

• Main Authors: KIM, SEON IN, LIM, SEON HUI, NAM, GI JU, KANG, YOUNG JO
• Format: Patent
• Language: English; Korean
• Published: 13.11.2014
• Subjects: ALLOYS; BLASTING; CHEMISTRY; CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION ORPROCESSING OF GOODS; DETAILS OR ACCESSORIES OF FURNACES, KILNS, OVENS, OR RETORTS,IN SO FAR AS THEY ARE OF KINDS OCCURRING IN MORE THAN ONE KINDOF FURNACE; FERROUS OR NON-FERROUS ALLOYS; FURNACES; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; HEATING; KILNS; LIGHTING; MECHANICAL ENGINEERING; METALLURGY; METALLURGY OF IRON; OVENS; PROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OFWROUGHT-IRON OR STEEL; RETORTS; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS; TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINSTCLIMATE CHANGE; TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS; WEAPONS

Disclosed are a method for operating an electric arc furnace and ferritic stainless steel manufactured thereby. The method for operating an electric arc furnace to produce ferritic stainless steel comprises: a first dissolving step of dissolving a raw material charged in an electric arc furnace; a second dissolving step of dissolving a raw material additionally charged in the electric arc furnace; and a step of charging ferrosilicon to the electric arc furnace to reduce a chrome component contained inside slag generated in the dissolving step. Moreover, the method thereof further comprises: a first injecting step of injecting a sub-raw material for protecting refractories of the electric arc furnace into the electric arc furnace at the initiation of the first dissolving step; and a second injecting step of injecting the sub-raw material into the electric arc furnace at the initiation of the second dissolving step. The sub-raw material contains powder calcium oxide and powder slaked dolomite. The present invention has the advantage of maximizing protection of a furnace wall and increasing the reduction rate of the chrome component inside slag by increasing fluidity of the slag by properly controlling basicity. Moreover, the present invention has the advantage of lowering manufacturing costs by reducing the input of powder calcium oxide which is a sub-raw material used in an electric arc furnace when ferritic 409L stainless steel is manufactured.