METHOD FOR MANUFACTURING HIGH CLEAN STEEL BY PERFORMING TOP BUBBLING AND BOTTOM BUBBLING ON MOLTEN STEEL WHILE INJECTING QUICKLIME AND FLUORITE INTO MOLTEN STEEL

摘要

PURPOSE: To provide a method for manufacturing high clean steel by performing dephosphorizing operation and temperature increasing operation on molten steel in a ladle furnace before proceeding molten steel to a degassing facility if phosphorus content of a steel product to be manufactured exceeds an upper limit. CONSTITUTION: In an ordinary steel manufacturing method comprising hot metal pretreatment process, converter refining process, degassing process and continuous casting process sequentially performed on hot metal discharged from a blast furnace, t he manufacturing method of high clean steel comprises a step of transporting the converter refining completed molten steel to a ladle furnace process; a step of performing dephosphorizing operation by bubbling molten steel while injecting quicklime and fluorite into molten steel; a step of performing arc heating operation on molten steel to compensate temperature dropped during the dephosphorizing operation; and a step of transporting molten steel to the degassing process.