ATMOSPHERE CORROSION RESISTING STEEL PRODUCTING METHOD IN MINI MILL PROCESS

摘要

PURPOSE: A method for producing high cleanliness steel in mini mill process is provided, which can reduce production cost and improve purity of molten steel. CONSTITUTION: The method is characterized in that HMS (heavy metal scrap) having a large quantity of residual elements occupies 70 to 80 wt.% of total charging material; cold pig iron or hot pig iron occupies 20 to 30 wt.% of total charging material; 0.13 to 0.33 wt.% of waste mortar is additionally charged to adjust Cu concentration in steel; 0.33 to 1 wt.% of quick lime is additionally charged into electric furnace to control P concentration in steel; terminal oxygen concentration of steel at tapping is regulated between 500 and 700 ppm; and molten steel is vacuum degassed in VTD (vacuum tank degasser) instead of degassing during tapping operation.