Method for smelting low-aluminium moulded steel

Abstract

The invention provides a method for smelting low-aluminium moulded steel, and relates to iron and steel smelting methods. The problem of component pattern breaking in existing low-aluminium moulded steel is solved. The method comprises the steps that molten iron after blast furnace ironmaking is subjected to pretreatment, wherein desulfuration is conducted mainly; the molten iron which is subjected to pretreatment enters a converter to be smelted, oxygen converter blowing is adopted, decarbonization, desulfuration, dephosphorization and desilicication are conducted in the blowing process, oxygen dissolved in the molten iron is removed in the later period of blowing, the process of steel tapping and alloying is conducted after blowing is completed, alloy is added according to steel grade demands, and low-aluminium moulded steel liquid is formed; the molten iron which is smelted by the converter enters a refining furnace to be subjected to the refining process of out of the converter, and a steel grade with the needed components is formed. The method can be widely applied to the smelting of the steel grade, in which temperature rising by blowing oxygen cannot be conducted in refining, and a low limit requirement for aluminium is asked, and the method is particularly applied to moulded steel with a low-aluminium requirement. According to the method, the components of the low-aluminium moulded steel are stably controlled, the problem of component pattern breaking in the low-aluminium moulded steel smelting process is solved, and component steel changing is avoided.

Description

technical field [0001] The invention relates to a method for smelting iron and steel, in particular to a method for smelting low-aluminum die cast steel. Background technique [0002] Low-aluminum die-cast steel grades require high tapping temperature because oxygen blowing cannot be carried out in the refining process to raise the temperature (such as steel grade GG800112). However, due to the high temperature required by the steel type, overblowing in front of the furnace often occurs. The blowing process of the converter is a process of reducing the C element. Overblowing means that the C element has been reduced to a very low level, so overblowing will cause the free oxygen in the molten steel to be too high. During the tapping process of the converter, since the C element is too low, it is necessary to add an alloy of C element. Generally, manganese carbon balls are added. According to the normal yield, the carbon yield is 95%, and the manganese yield is also 95%. Wh...

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Problems solved by technology

[0003] The purpose of the present invention is to overcome the problems existing in the prior art and provide a method for smelting low-aluminum die-cast steel, which can solve the problem that C and Mn enter molten steel from slag after the refining treatment is completed during the smelting process of low-aluminum die-cast steel

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