Process method for reducing RH vacuum decarbonization end-point oxygen content of ultra-low-carbon steel

Abstract

The invention provides a process method for reducing RH vacuum decarbonization end-point oxygen content of ultra-low-carbon steel and belongs to the technical field of production and processing of ultra-low-carbon steel. The process method comprises the following steps: 1) in an early period of RH vacuum decarbonization, adding a pollution-free deoxidant from a feed bin to a vacuum chamber, and removing partial oxygen from the steel; 2) further reducing vacuum degree for deep carbonization; and 3) after the RH vacuum decarbonization treatment is finished, using aluminum particles as a final deoxidant, and deoxidizing and alloying other alloy elements according to steel grade requirements. By the process method, the RH decarbonization end-point oxygen content can be reduced, and the active oxygen content of molten steel is controlled to be 250-400ppm when the RH decarbonization is finished, so that the consumption of final deoxidizing aluminum particles is reduced, the inclusion content in the molten steel is reduced, the cleanness of the molten steel is improved, the production cost is reduced and the quality of the ultra-low-carbon steel is obviously improved.

Description

technical field [0001] The invention belongs to the technical field of ultra-low carbon steel production and processing, and more specifically relates to a process for reducing the oxygen content at the RH decarburization end point of ultra-low carbon steel. Background technique [0002] At present, ultra-low carbon IF steel has become the third-generation deep-drawing steel for automobiles. Due to the use of RH vacuum refining, the contents of carbon [C] and nitrogen [N] in molten steel can be controlled below 25ppm, and the content of carbon [C] can be even lowered. At the same time, due to the addition of microalloying elements such as titanium [Ti] or [Nb] in ultra-low carbon steel, it combines with carbon [C] and nitrogen [N] interstitial atoms in the steel to form carbonitrides, becoming interstitial atom-free steel. In this way, there is no aging phenomenon in the material. In addition, due to the ultra-low carbon composition design, the structure of the finished ste...

AI Technical Summary

Problems solved by technology

In the prior art, when using the "converter-alloy fine-tuning station-RH-continuous casting" process route to produce ultra-low carbon steel, due to the difficulty in coordinated control of the converter end point C, T and [0], and the high oxidation of ladle top slag, in At the end of RH vacuum decarburization, the active oxygen of molten steel shows two characteristics: (1) unstable between furnaces; (2) high active oxygen content, between 300ppm-800ppm

This not only increases the consumption of deoxidized aluminum particles in the RH vacuum refining process, which leads to an increase in cost, but also increases the inclusions generated in molten steel during deoxidation, affecting the cleanliness of molten steel

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