SECONDARY REFINING METHOD OF MOLTEN STEEL THROUGH CONTROL OF BUBBLING PATTERN

摘要

PURPOSE: A secondary refining method of molten steel through control of bubbling pattern is provided to minimize uniform mixing time of molten steel by optimizing a ratio of bubbling rate blown up and bubbling rate blown down and height of upper blowing lance in the secondary refining process of steelmaking. CONSTITUTION: In a secondary molten steel refining process of floating inclusions in molten steel, thereby removing the floated inclusions as upper bubbling an inner gas from an upper blowing lance dipped from an upper part of teeming ladle and lower bubbling the inert gas to a lower part of the teeming ladle, the secondary refining method of molten steel through control of bubbling pattern comprises a step of installing the upper blowing lance at an elevation of 450 to 550 mm from the bottom of the teeming ladle; and a step of controlling a ratio of bubbling rate blown up and bubbling rate blown down to 1.6 to 1.7:1.