Method for making foamed slag during stainless steel electric furnace smelting

Abstract

The invention discloses a method for making foamed slag during stainless steel electric furnace smelting. The method is characterized by comprising the steps of: 1) conducting burdening for stainless steel electric furnace smelting, controlling the mass ratio of the C element to the total raw material at 1.5-3.0% and the mass ratio of the Si element to the total raw material at 0.6-0.9%; 2) performing energization and oxygen blowing operation so as to melt the burdened raw materials, and adding a slag-making material to make furnace slag; 3) after a metal molten pool takes an initial shape and liquid furnace slag forms, adding foaming balls in two batches to foam the furnace slag, keeping the adding time interval of the two batches of foaming balls at 3-5min and the adding amount of every batch of foaming balls at 2.5-4kg per ton of steel, with the foaming balls comprising iron oxide, carbon powder and limestone as effective components, and maintaining the oxygen blowing operation in the furnace slag foaming process after adding the foaming balls; 4) employing silicon powder or silicon iron to conduct reduction on Cr2O3in the furnace slag and stopping oxygen blowing; and 5) ending smelting. The method provided by the invention can protect furnace lining and increase electric arc thermal efficiency.

Description

technical field [0001] The invention relates to an alloy steel smelting method, in particular to an alloy steel electric furnace smelting method. Background technique [0002] Foaming slag in the process of smelting stainless steel in electric furnace can better protect the arc, thereby further promoting the absorption of arc energy by molten steel and slag, and also avoiding arc energy radiation to the furnace wall to damage the furnace lining. Foaming slag technology is widely used in low alloy steel smelting and carbon steel smelting. However, in the stainless steel smelting process, it is very difficult to produce good foamy slag, because oxygen blowing in the stainless steel electric furnace smelting process mainly produces chromium oxide instead of iron oxide, and the presence of chromium oxide will not only deteriorate the fluidity of slag risk, and the reaction rate of chromium oxide with carbon in molten steel is much lower than the reaction rate of iron oxide with...

AI Technical Summary

Problems solved by technology

However, the cost of pellets using iron powder as raw material is high, and the carbon contained in the molten steel will enter the molten steel after being added to the molten pool, and it cannot be guaranteed that all of it will react with the oxides in the slag to generate CO gas to make foam slag

In addition, the technical solution involved in this patent document needs to add new equipment to meet the demand for continuous feeding during use, which undoubtedly increases the cost and operational complexity of the practical application of the technical solution

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