Patent ID: 6309443
Filing Date: 2001-10-30
Classification: B23K,C21C,C21D

Abstract:
A simplified ladle refining process for refining a molten steel in a ladle comprising inserting an immersion snorkel into a ladle and blowing an oxidizing gas onto the surface of a molten steel within the immersion snorkel through a lance while the molten steel is being stirred by blowing an inert gas through the bottom of the ladle, wherein the lance has a ratio (d.sub.0 /d.sub.t) of a nozzle outlet diameter d.sub.0 (mm) to a nozzle throat diameter d.sub.t (mm) of from 1.2.alpha. to 2.5.alpha. wherein .alpha. is calculated by the formula (1):.alpha.=[(1/M.multidot.{(1+0.2.times.M.sup.2)/1.2}.sup.3 ].sup.1/2 (1)wherein M={5.times.(P.sup.2/7 -1)}.sup.1/2 wherein P is a back pressure (kgf/cm.sup.2, absolute pressure).