Control method of ultra-low carbon, ultra-low Ti aluminum silicon killed steel

摘要

The present invention provides a method for controlling extremely low Ti in extra low carbon AlSi-killed steel, the weight percentage of the chemical composition of the extra low carbon AlSi-killed steel comprising: C‰¤0.005%, Si: 0.1-3.4%, Mn: 0.1-0.5%, P‰¤0.2%, S‰¤0.002%, A1: 0-1.2%, N‰¤0.005%, Ti‰¤0.0015 and a balance substantially being Fe and inevitable impurities; the liquid steel having said chemical composition is obtained by hot metal preprocessing, smelting, retained RH smelting and ingoting, wherein the top ladle slag is modified, and calcium-aluminum based modifier of 0.6-1.7kg/t steel are added, so as to ensure a controlling demand that when refined RH decarburization is over, the content of T.Fe in top ladle slag composition ‰¥5%, the content of Al 2 O‰¤23%; when refined RH decarburization is over, ferrosilicium, ferroaluminum or ferromanganese is employed to perform deoxide and alloying, then perform a deep desulfurization, and desulfurizing efficiency is 50% to 70%.