Method for smelting very-low carbon and high silicon stainless steel by AOD

Abstract

The invention discloses a method for using AOD to smelt extra-low high sillca stainless steel which includes the following technical steps: batching-crude melting by an arc furnace-steel exchange-AOD refining-argon blowing-tapping; wherein, the AOD refining also includes the following steps: removing slag-decarbonizing-adding slag materials-adding a reducer and an auxiliary agent-removing partial slag-fine tuning on the components; the method is characterized in that: a, the argon oxygen blowing in the decarbonizing technique is divided into an initial decarbonizing period and a secondary decarbonizing period; the initial decarbonizing period and the secondary decarbonizing period are blown according to a different argon-oxygen ratio; b, the slag system adopted in the technique of adding the slag materials is a slag system of CaO, Al2O3, MgO and SiO2. The method of the invention leads a steel liquid to finish crude smelting in the arc furnace, namely being capable of stably producing the extra-low stainless steel ( the C is equal to or less than 0.015 percent) in the AOD without a vacuum device, saving the consumption of the reducer, having a low cost, being capable of carrying out industrial batch production, utilizing the existing smelting device to the largest extent as well and saving a plurality of investment.

Description

technical field [0001] The invention relates to a metallurgical process, in particular to a method for smelting extremely low-carbon high-silicon stainless steel by using AOD. Background technique [0002] Very low-carbon high-silicon stainless steel (00Cr14Ni14Si4) is a new material for corrosion resistance to concentrated sulfuric acid, which requires a carbon content of less than 0.015%. Under the current industrial production conditions, VOD and vacuum induction furnaces can be successfully smelted. The biggest difficulty in its production is the control of carbon content, which must be vacuum refined. At present, the domestic production of stainless steel is dominated by AOD refining furnaces. , more than 80% of stainless steel is produced by AOD, so there is a shortage in industrial mass production, and the cost of producing this type of steel with VOD and vacuum induction furnace is also high, especially the vacuum induction furnace cannot blow oxygen and decarburize,...

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Problems solved by technology

Under the current industrial production conditions, VOD and vacuum induction furnaces can be successfully smelted. The biggest difficulty in its production is the control of carbon content, which must be vacuum refined. At present, the domestic production of stainless steel is dominated by AOD refining furnaces. , more than 80% of stainless steel is produced by AOD, so there is a shortage in industrial mass production, and the cost of producing this type of steel with VOD and vacuum induction furnace is also high, especially the vacuum induction furnace cannot blow oxygen and decarburize, only Carry out trace decarburization under high vacuum, the required raw materials are very expensive (such as metal silicon, metal chromium, metal manganese, etc.), the production cost is high, and the output is small

However, if oxygen blowing decarburization is used in non-vacuum AOD smelting, when the carbon content is ultra-low and the decarburization efficiency is ultra-low, it is easy to return to carbon during reduction due to the presence of high silicon, and the carbon content often exceeds 0.02%, which is not only successful The rate is low, and a lot of manpower and material resources are wasted

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