METHOD FOR CONTROLLING TITANIUM CONTENT IN ULTRA-LOW CARBON KILLED STEEL

摘要

A method for controlling titanium content in ultra-low carbon killed steel. The steel comprises (wt%): C=0.005%, Si: 0.1-3.4%, Mn: 0.1-0.5%, P=0.2%, S=0.002%, Al: 0-1.2%, N=0.005%, Ti=0.0015%, trace impurities and balance Fe. The steel is obtained by pretreating molten iron, smelting, RH refining and casting, wherein, it is ensured by adding Al-Ca based modifier to top slag of ladle that the top slag of ladle comprises T.Fe=5% and Al2O3=23% when decarburization of RH refining is completed. Upon the completion of decarburization of RH refining, the molten steel is deoxidated and alloyed by using Si-Fe, Al-Fe or Mn-Fe, and then is deep desulfurized. The rate of desulfurization is 50%-75%.