A kind of production method of low carbon and high chromium steel

Abstract

The invention discloses a production method for low-carbon high-chromium steel. The production method comprises the following steps: primarily melting molten steel by adopting a converter, wherein the final tapping temperature is controlled at 1670-1690DEG C, the C content of tapping liquid steel is regulated to be 0.04-0.06wt% and the oxygen activity is regulated to be 600*10<-6> to 700*10<-6>, and ferrochrome alloy is quantitatively added according to a ratio of 40-50kg / t liquid steel in the steel tapping process; performing primary refining to the primarily molten liquid steel in a ladle refining furnace, wherein the ferrochrome alloy is added when the primary refining starts to regulate the content of Cr in the liquid steel to be 3.6-4.0wt%, and the final tapping temperature of the primary refining is controlled to be 1645-1655DEG C; carrying out decarburization treatment to the primarily refined liquid steel in an RH furnace to regulate the content of C to be 0.02% below; then carrying out secondary refining to the decarburized liquid steel in the ladle refining furnace to finally obtain the low-carbon high-chromium steel, wherein the ferrochrome alloy is added when the secondary refining starts to regulate the content of Cr in the liquid steel to be 3.8-4.2wt%, and the final tapping temperature of the secondary refining is controlled to be 1595-1605DEG C. The low-carbon high-chromium steel is obtained by adopting the method.

Description

technical field [0001] The invention belongs to the technical field of iron and steel metallurgy, and more specifically relates to a production method of low-carbon high-chromium steel. Background technique [0002] At present, compared with the production process of the converter, the main problems faced by the production of low-carbon high-chromium steel are temperature control and carbon content control of the steel, because when the converter is used to smelt high-chromium steel, the amount of alloy added is large. The amount of ferrochromium alone is about 16 tons. If the method of one-time addition after tapping the converter is adopted, coupled with the influence of the temperature drop of the tapping, the temperature drop of the molten steel will reach more than 120°C, and the heat loss is too large. It is difficult to control the process temperature; at the same time, due to the low carbon content (≤0.03%), the amount of alloy added is large, the heating time is lon...

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Problems solved by technology

[0002] At present, compared with the production process of the converter, the main problems faced by the production of low-carbon high-chromium steel are temperature control and carbon content control of the steel, because when the converter is used to smelt high-chromium steel, the amount of alloy added is large. The amount of ferrochromium alone is about 16 tons. If the method of one-time addition after tapping the converter is adopted, coupled with the influence of the temperature drop of the tapping, the temperature drop of the molten steel will reach more than 120°C, and the heat loss is too large. It is difficult to control the process temperature; at the same time, due to the low carbon content (≤0.03%), the amount of alloy added is large, the heating time is long, and the carburization of the alloy and the carburization of the heating have a great impact on the control of carbon, so general alloys cannot be used steel production process