| 摘要 |
PURPOSE:To refine molten steel by decarburization without oxidizing its components in the stage of refining the molten steel by the use of double pipe tuyeres by an AOD method by blowing oxygen through the inside pipe of double pipe tuyeres and mixing a dilute gas with the oxygen on progression of the decarburization. CONSTITUTION:In the stage of refining stainless steel by decarburization by an AOD method, gaseous hydrocarbon is blown through the outside pipe of double pipe tuyeres at 60m/sec velocity of flow and gaseous pure oxygen is blown through the inside pipe to oxidize and decarburize the C in the stainless steel. When the content of C in the melt decreases down to about 0.7%, a gaseous mixture of 2:1-4:1 oxygen and an inert gas such as Ar is blown through the inside pipe in lieu of the oxygen. The gaseous Ar dilutes the gaseous CO formed by the decarbuirzation reaction and decreases the partial pressure thereof, whereby the C is preferentially oxidized and is removed down to <0.06% C grade without oxidation of Cr and Fe in the melt, and the low carbon stainless steel is refined in a short time with a small amt. of the Ar used. |
