METHOD FOR EFFICENTLY DECARBURIZATION-BLOWING STAINLESS STEEL

摘要

PROBLEM TO BE SOLVED: To reduce a reducing material cost by executing the oxygen-blowing decarburization refining while adding ferro-chromium alloy into molten steel at the specific temp. after specifying Al₂O₃ concn. in slag and C concn. in the molten steel. ;SOLUTION: Crude molten stainless steel is melted by using molten iron of a blast furnace and ferro-chromium alloy and then, the decarburization- refining is executed in a refining furnace. At this time, a condition just before adding or during adding the ferro-chromium alloy is regulated. That is, the molten steel temp. just before adding the ferro-chromium alloy is made to 1450-1600°C by adding metallic Al or aluminum dross containing the metallic Al as the temp. raising material to raise the temp. into the molten iron charged into the refining furnace. Then, after containing 10-30% Al₂O₃ concn. in the slag and 2.5-4.0% [C] concn. in the molten iron, the oxygen-blowing decarburization-refining is executed while continuously adding the ferro- chromium alloy. By this method, the effective refining of the stainless steel can be executed.;COPYRIGHT: (C)1997,JPO