The slug immediately after the steel

摘要

PROBLEM TO BE SOLVED: To stably produce a high cleanliness steel by uniformly and sufficiently reducing slag in a ladle to prevent the reaction between molten steel and the slag. ;SOLUTION: In the producing method of the highly clean steel the molten steel 5 obtd. from a converter refining is tapped into a ladle 3 from the converter and a slag reforming agent 7 containing Al is added into the slag 6 floated up on the molten steel in the ladle to reform the slag and successively, a vacuum degassing treatment is applied to produce the above steel. In such a case, while the slag just after tapping from the converter is in the molten state, the slag refining agent is added by using a chute 10 whose tip part is shiftable and apart from the molten steel surface in the ladle by ≥500 mm in the vertical direction, inclined at 30-60°C angle to the molten steel surface, while shifting the tip part of the chute above the ladle.;COPYRIGHT: (C)2000,JPO