Steel ladle top slag modification method suitable for low-carbon and ultra-low-carbon steel

Abstract

The invention discloses a steel ladle top slag modification method suitable for low-carbon and ultra-low-carbon steel. The steel ladle top slag modification method comprises the following steps of 1,not blowing argon into a steel ladle in a converter tapping process without adding any deoxidizing agent or slagging material; 2, adding a strong deoxidation iron alloy with the specific gravity between that of top slag and that of molten steel into the steel ladle after tapping is completed, wherein the adding amount of the strong deoxidation iron alloy is determined according to the actual molten steel amount in the steel ladle; 3, adding a lime flux into the steel ladle after the strong deoxidation iron alloy is added, wherein the lime adding amount is determined according to the actual molten steel amount in the steel ladle; 4, adding a strong deoxidation alloy into molten steel in a vacuum chamber when RH circulating vacuum breaking is finished and before the molten steel drops and just starts to flow out of the vacuum chamber, wherein the adding amount of the strong deoxidation alloy is determined according to the actual molten steel amount; and 5, performing RH decarburization,deoxidation and alloying operation methods which are the same as conventional methods currently in effect in a steel plant. By applying the method, the ladle top slag oxidability can be remarkably changed, the cleanliness indexes of the molten steel are improved to different degrees, the field environment is not polluted in the modification process, and environment protection requirements can be met.

Description

technical field [0001] The invention belongs to the technical field of steelmaking, and relates to a ladle top slag upgrading method, in particular to a ladle top slag upgrading method suitable for low-carbon and ultra-low carbon steel. Background technique [0002] The low-carbon and ultra-low-carbon steels in the "converter-RH-continuous casting" process path are generally aluminum-killed steels with relatively high aluminum content, and the acid-soluble aluminum content in molten steel is relatively high. During the process, especially in the later stage of pouring, the oxygen in the ladle slag will continuously react with the acid-soluble aluminum in the molten steel to form Al which is not conducive to the quality of the molten steel. 2 o 3 Inclusions lead to a decrease in the cleanliness of molten steel. A large number of experiments and industrial production results have confirmed that the iron oxide content in the ladle top slag is directly related to the aluminum ...

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Problems solved by technology

[0011] Aiming at the technical problems of major safety hazards, serious environmental pollution and poor modification effect in the ladle top slag modification method mentioned in the background technology, the purpose of the present invention is to provide a method suitable for low-carbon and ultra-low-carbon Steel ladle top slag modification method, this modification method can significantly change the oxidation of ladle top slag, the cleanliness index of molten steel has been improved to varying degrees, and the modification process does not pollute the site environment, which can meet environmental protection requirements

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