LADLE REFINING METHOD OF MOLTEN STEEL

PROBLEM TO BE SOLVED: To provide a ladle refining method of a molten steel capable of realizing a targetted very low sulfur molten steel in a short time, when a molten steel in a ladle is desulfurized by ladle refining of the molten steel accompanying electric heating to produce a very low sulfur steel.SOLUTION: In a ladle refining method of a molten steel in which a flux layer 4 containing CaO is formed on a surface of a molten steel 3 in a ladle 1, and an electrode is dipped in a flux layer to energize, a gas blowing plug 2 is arranged at two positions on a bottom part of the ladle 1, and, regarding a flow rate of a gas blown from each of the gas blowing plugs, when a flow rate having larger gas flow rate is assigned to Qand the other gas flow rate is assigned to Q(unit for both is NL/min/t), Qand Qsatisfy the following (1) to (3) formulas.1.02≤Q/Q≤2.30 (1), 0.420≤Q≤4.25 (2), and 0.420≤Q≤4.25 (3)SELECTED DRAWING: Figure 1 【課題】取鍋内の溶鋼を、通電加熱を伴う溶鋼の取鍋精錬によって脱硫して極低硫鋼を製造するに際し、目標とする溶鋼の極低硫化を短時間で実現することができる、溶鋼の取鍋精錬方法を提供する。【解決手段】取鍋１内の溶鋼３表面にＣａＯを含むフラックス層４を形成し、電極をフラックス層に浸漬させて通電する溶鋼の取鍋精錬方法において、取鍋１の底部にガス吹き込み用プラグ２を２カ所に配置し、当該ガス吹き込み用プラグそれぞれから吹き込まれるガスの流量について、ガス流量が大きい方のガス流量をＱB、他方のガス流量をＱA（いずれも単位はＮＬ／ｍｉｎ／ｔ）とし、ＱA、ＱBが以下に示す（１）〜（３）式を満たす。１．０２≦ＱB／ＱA≦２．３０ （１）０．４２０≦ＱA≦４．２５ （２）０．４２０≦ＱB≦４．２５ （３）【選択図】図１