Steel ladle top slag modification method suitable for IF (Interstitial-Free) steel

Abstract

The invention discloses a steel ladle top slag modification method suitable for IF steel. The steel ladle top slag modification method is characterized in that metallurgical lime is not added in the process of converter steel outputting, liquid steel is firstly added with aluminum particles immediately through a material distributing device after reaching an alloy trimming station, then the metallurgical lime is added through the material distributing device, and still standing is performed for 3-5 min at the material distributing position before leaving the station. By means of the steel ladle top slag modification method suitable for the IF steel, the technical problems that an existing top slag modification process pollutes the environment seriously, the oxygen consumption quantity in the modification process is large, the modification agent cost is high, and the like are effectively solved, high-quality, environment-friendly and economical production of the IF steel is realized, and the steel ladle top slag modification method suitable for the IF steel has a good application prospect.

Description

technical field [0001] The invention belongs to the technical field of steelmaking and smelting, and more specifically relates to a ladle top slag reforming method suitable for IF steel. Background technique [0002] IF steel, the full name of Interstitial-Free Steel, is interstitial-free steel, which has excellent deep drawing performance and is widely used in automobiles, home appliances and other industries. In IF steel, due to the low content of C and N, a certain amount of titanium (Ti), niobium (Nb) and other strong carbon-nitrogen compound forming elements are added to completely fix the interstitial atoms such as carbon and nitrogen in ultra-low carbon steel as Carbonitrides, resulting in clean ferritic steel without interstitial atoms. In steelmaking production, generally adopt the technological process of "hot metal pretreatment → top-bottom combined blowing converter → alloy fine-tuning station → RH furnace → slab continuous casting". [0003] The top slag modif...

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Problems solved by technology

This ladle top slag reforming process has the following disadvantages: ①After putting the reforming agent into the ladle, due to the chemical reaction between the reforming agent and the slag, a large amount of thick smoke and dust will continue to be discharged, and even the molten steel is hoisted to the RH treatment process. Continue to discharge a large amount, which will seriously pollute the on-site working environment and RH safe operation, which is not conducive to human health; Argon must be blown at the bottom of the ladle when adding the modifier. When the modifier is added, the aluminum in the modifier reacts with the oxygen in the molten steel, which consumes the oxygen required for the decarburization reaction in the RH process, resulting in frequent occurrence of RH oxygen supplementation. It is not conducive to the cleanliness of molten steel and reduces the efficiency of RH smelting; ③The modifier needs to be purchased from outside, and its quality varies, which is not conducive to the control of costs and the quality of molten steel by steel mills

The advantage is that the dust generated when the modifier is added enters the air cooler of the RH vacuum pump system, and the dust cools and settles in the air cooler. After the vacuum treatment is completed, it can be discharged centrally through the ash discharge valve. It will overflow, but the disadvantages are: ① Increase the cleaning frequency of the RH vacuum pump system, and affect the vacuum pumping effect of the vacuum pump, which is not conducive to the decarburization of molten steel; ② Need to purchase modifiers, which is not conducive to cost reduction for steel plants; Carbon is inevitably brought in, resulting in unstable control of the carbon content of IF steel, which is easy to exceed the standard

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