MELTING AND MANUFACTURING METHOD OF Ti-ADDED ULTRA-LOW CARBON STEEL

摘要

PROBLEM TO BE SOLVED: To provide a method for melting and manufacturing a Ti-added ultra-low carbon cold-rolled steel sheet by which casting can be performed without causing nozzle clogging.;SOLUTION: When melting and manufacturing the ultra-low carbon Ti-killed steel containing ≤0.020 wt.% C and ≥0.010 wt.% Ti, a Ti-containing alloy is added to a decarbonized molten steel for deoxidization to obtain a killed molten steel with a composition satisfying a relation of Al≤(wt.% Ti)/5. Then, an alloy for adjusting the inclusion composition which contains at least one selected from ≥10 wt.% Ca and ≥5 wt.% REM and at least one selected from Fe, Al, Si and Ti, is added to the killed molten steel to adjust the oxide composition in the molten steel so that it comprises ≤90 wt.% of Ti oxide, ≥10 wt.% but ≤50 wt.% of CaO and/or REM oxide and ≤70 wt.% of Al₂O₃.;COPYRIGHT: (C)2006,JPO&NCIPI