METHOD FOR VACUUM-REFINING MOLTEN STEEL HAVING HIGH CIRCULATING FLOW CHARACTERISTIC

摘要

PURPOSE: To provide an efficient refining method, by which decarburizing speed is not always lowered from just after starting the decarburizing treatment to the extra-low carbon range, related to the decarburizing treatment in a vacuum refining furnace. ;CONSTITUTION: In the vacuum refining method for molten steel, a large diameter straight barrel shaped vessel 1 is immersed into the molten steel 5 in a ladle tapped from a refining furnace and also, the pressure in the straight barrel immersion vessel is reduced and stirring gas is supplied from the lower position 3 than the position at the lower end of the immersion vessel and also, gas is supplied from the wall surface of the immersion vessel, too. The circulating flow between the molten steel in the immersion vessel, in which the decarburizing reaction generates, and the molten steel in the ladle, is promoted to the extreme condition by arranging a gas blowing hole 4 in the angle range from 0° to 60° at both right and left sides to the straight line connecting the center axis B in the immersion vessel and the projected point A of the gas supplying position 3 at the lower part, on the wall surface of the immersion vessel.;COPYRIGHT: (C)1995,JPO