304 stainless steel smelting method by AOD (argon oxygen decarburization) Converter

Abstract

A 304 stainless steel smelting method by an AOD (argon oxygen decarburization) converter comprises 1) a silicon aluminum oxidation stage; 2) a main decarbonization stage; 3) a dynamic decarburization stage; 4) a reduction stage; and 5) desulfurization alloying; and is characterized in that: silicon mixed manganese ore balls are added in the reduction stage, the silicon mixed manganese ore balls are prepared by mixing and pressing manganese ore powder with a manganese percent content of 25-40% and ferrosilicon powder in a ratio of 7:3, the dosage of the silicon mixed manganese ore balls is 0.01-0.02 ton / ton steel, the silicon mixed manganese ore balls are averagely added in 2 to 3 times at intervals of 2 to 3 minutes; the decarbonization stage smelting temperature of the AOD converter is 1560 to 1620 DEG C; in the desulfurization alloying stage, lime is supplemented, and the lime adding amount is 0.04-0.06 ton / ton steel. According to the method, silicon mixed manganese ore is used for replacing manganese alloy, the production cost can be effectively reduced, the purity of molten steel can be ensured, manganese alloy production link can be directly omitted, and the pollution of the environment can be reduced.

Description

technical field [0001] The invention relates to the field of stainless steel smelting, in particular to a method for smelting 304 stainless steel in an AOD converter. Background technique [0002] The core of stainless steel smelting technology is "decarburization and chromium preservation", and the mainstream stainless steel smelting equipment is AOD furnace. From the perspective of the smelting process of the AOD furnace, it is mainly divided into the following five stages: [0003] 1) silicon-aluminum oxidation stage; 2) main decarburization stage; 3) dynamic decarburization stage (can be further subdivided into 3 to 4 stages); 4) reduction stage; 5) desulfurization alloying. [0004] When the existing technology produces 304 stainless steel grades, in the smelting reduction stage of the AOD furnace, in order to make the Mn element of the AOD tapping molten steel meet a certain composition requirement, a certain amount of manganese alloy must be added in the reduction st...

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Problems solved by technology

[0004] When the existing technology produces 304 stainless steel grades, in the smelting reduction stage of the AOD furnace, in order to make the Mn element of the AOD tapping molten steel meet a certain composition requirement, a certain amount of manganese alloy must be added in the reduction stage, and the price of the manganese alloy is high, making production The cost is very high. At the same time, due to the complex manufacturing process, high price and serious environmental pollution of the existing manganese alloy, the large-scale application of this type of manganese alloy is restricted to a certain extent, and it is especially not suitable for the market where the profit margin of stainless steel smelting is extremely small. Environment use

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