Method for silicon alloying and calcium treatment of molten steel by using metal-containing calcium-silicon-iron alloy

Abstract

The invention discloses a method for carrying out molten steel silicon alloying and calcium treatment by using metal-calcium-containing silicon-iron alloy, and belongs to the field of steel metallurgyrefining. The method is characterized in that in the tapping process after converter smelting, silicon alloying is not carried out or partial silicon alloying is carried out, the steel liquid aluminum deoxidation treatment and slag adding pre-refining are carried out at the same time, and the aluminum content is controlled according to the steel type requirement upper limit; and the metal-calcium-containing silicon-iron alloy is added into molten steel after secondary refining to carry out silicon alloying and calcium treatment, then argon is blown at a larger flow for stirring for 1-3 minutes so as to promote melting of the alloy, and then the argon is blown at a smaller flow for stirring so as to out low-flow argon blowing stirring to uniformize molten steel components and promote modification and floating of inclusions. According to the method for carrying out molten steel silicon alloying and calcium treatment by using the metal-calcium-containing silicon-iron alloy, the metal calcium contained in the silicon-iron alloy is utilized, and the targets of molten steel silicon alloying and calcium treatment are achieved at the same time by adjusting the silicon alloying time, so that the conventional calcium feeding line operation is reduced or even eliminated, and the production cost is reduced; and meanwhile, the situation of molten steel splashing caused by a calcium feedingline is avoided, oxygen increasing and nitrogen increasing of the molten steel are reduced, the operation stability and the yield of the calcium are improved, and then the cleanliness of the molten steel is also improved.

Description

technical field

[0001] The invention relates to a method for simultaneously performing silicon alloying and calcium treatment of molten steel by using ferrosilicon alloy containing metallic calcium, and belongs to the field of iron and steel metallurgical refining. Background technique

[0002] In the production process of aluminum deoxidized steel, calcium treatment process is widely used to prevent the submerged nozzle from being blocked during casting. In addition, calcium treatment is also widely used in the modification of MnS in pipeline steel and other steels to avoid the formation of hydrogen-induced cracks during service. In iron and steel enterprises, calcium treatment is currently mainly carried out by feeding various calcium-containing cored wires into molten steel. These calcium-containing cored wires include pure calcium wires, silicon-calcium wires, and aluminum-calcium wires. In addition to increasing costs, due to the high vapor pressure of calcium, this met...

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