A method for smelting high manganese stainless steel by aod and an aod furnace

Abstract

The invention discloses a method for smelting high-manganese stainless steel through AOD. The method comprises a preparatory process, a decarburization process, a prereduction process and a reduction process, wherein in the prereduction process, a ferrosilicon alloy serves as a deoxidizing agent and an alloying agent for deoxidization, manganese is added in a concentrated manner for manganese alloying, manganese is added in a batched manner in the manganese alloying process, heating is conducted while manganese is added, and meanwhile various technological parameters are reasonably controlled. According to the method for smelting the high-manganese stainless steel through AOD, for AOD smelting on the high-manganese stainless steel with the manganese content larger than 15%, the manganese alloying technology is improved, furnace temperature, an oxygen blowing parameter and the using dosage and time of the deoxidizing agent and the alloying agent are reasonably controlled, oxidization or burning loss of manganese are greatly reduced, and not only is the recycling rate of manganese increased, but also the loss, caused by high temperature, of an AOD furnace lining is reduced. The invention further discloses an AOD furnace. Installing of a bottom air blowing tube can be convenient to achieve, pouring of the AOD furnace is uniform and adjustable, slag flowing is uniform and capable of saving labor, the workload is reduced, the slag flowing speed is increased, the slag flowing quality is improved, and the manganese alloying process is accelerated.

Description

technical field [0001] The invention belongs to the field of metallurgy, in particular to the field of smelting stainless steel, in particular to an AOD method for smelting high-manganese stainless steel and an AOD furnace. Background technique [0002] In general stainless steel, the manganese content does not exceed 2.0%, such as 304, 316L, 310, etc., while the manganese content of stainless steel containing manganese will be 4-10%, such as chromium-manganese stainless steel such as 201, 202, and S20910. In recent years, a new type of high manganese stainless steel has been developed. The increase of manganese will greatly increase the solubility of nitrogen in the steel, and it is also an austenite forming element. The highest manganese has reached more than 22%. [0003] The Chinese invention patent application with the application announcement number CN 105039648 A discloses a method for smelting low-carbon and high-manganese content molten steel with an argon-oxygen de...

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Problems solved by technology

The actual situation is that this method is only applicable when the manganese content is not high. When the manganese content exceeds 15%, the alloy addition amount in a single furnace is too large, which will greatly reduce the AOD refining temperature. Al-Si oxidizes and heats up, and it needs to be reduced again. During the heating process, a large amount of manganese will volatilize, increase the amount of manganese, and reduce the recovery rate. At the same time, due to the large amount added, the refining temperature of AOD before reduction will exceed 1800 ° C, exceeding AOD The refractory temperature of the furnace lining refractory material is 1750°C, which reduces the furnace life of AOD

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