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CN-117066466-B - Method for processing calcium abnormality of low-carbon low-silicon aluminum-containing steel and method for producing low-carbon low-silicon aluminum-containing steel

CN117066466BCN 117066466 BCN117066466 BCN 117066466BCN-117066466-B

Abstract

The invention discloses a calcium abnormity processing method of low-carbon low-silicon aluminum-containing steel and a production method of low-carbon low-silicon aluminum-containing steel, wherein a calcium line is fed to molten steel in a bottom argon blowing air supply mode, the calcium line is fed to each ton of molten steel in a normal condition at a calcium feeding linear speed of 150-250m/min, and the calcium content in the discharged molten steel is 15-25ppm. The variety and the quantity of inclusions in molten steel are effectively controlled by controlling the calcium feeding linear speed, the calcium feeding linear quantity and the like, so that the rising condition of a stopper rod caused by the nodulation of a tundish nozzle is reduced.

Inventors

  • HUANG HANZHE
  • HU XIANFENG
  • LI LI
  • REN SHIGANG
  • ZHANG XIAOLONG
  • XU ZHONG
  • XIE LEMING
  • ZENG LINGYU
  • XUN ZHONGZHONG
  • YU DAHUA
  • LIU ZHILONG
  • QIN XIAOFENG
  • LU JINLONG
  • LI ZHIRONG
  • LONG GU

Assignees

  • 广东中南钢铁股份有限公司

Dates

Publication Date
20260508
Application Date
20230919

Claims (5)

  1. 1. The method for processing the calcium abnormality of the low-carbon low-silicon aluminum-containing steel is characterized by comprising the steps of normal production and abnormality processing, wherein a calcium line is fed to molten steel in a bottom argon blowing air supply mode: Normal production, wherein the feeding amount of the calcium wire is 1.05 m-1.35 m per ton of molten steel, the feeding linear speed of the calcium wire is 150-250m/min, and the calcium content in the discharged molten steel is 15-25ppm; When any one of the following abnormal conditions occurs, taking a steel sample after feeding the calcium line for 2.5-3.5min to confirm that the calcium content is A, and if the A is less than 15 ppm, determining whether to feed the calcium line according to the soft blowing time after the calcium line is expected to be fed; ① Adopting a production mode of aluminum-free steel and low-carbon low-silicon aluminum-containing steel, and casting a2 nd furnace; ② Furnace 1 after new calcium line replacement or furnace 2 after binding calcium line; ③ The distance between the outlet and the molten steel surface is more than 800 mm; ④ When the calcium wire is fed, the obvious splashing times are less than or equal to 2 times, wherein the splashing refers to the phenomenon that the calcium steam floats upwards to bring steel and slag out and is scattered from a ladle opening when the calcium wire is fed, and the obvious splashing refers to the splashing that the distance between the scattered steel flower falling point and the ladle wall is more than or equal to 3 m; if A is less than 10ppm, immediately feeding the calcium wire, wherein the quantity B=60/A+150m of the calcium wire is fed to each furnace of molten steel; if A is more than or equal to 10 and less than or equal to 12ppm and the soft blowing time is more than or equal to 13min after the calcium wire is expected to be fed, the amount B of the calcium wire fed by each furnace of molten steel is 40-60m; if A is more than or equal to 10 and less than or equal to 12ppm, and the soft blowing time is less than 13min after the calcium wire is fed in a pre-feeding mode, the calcium wire is not fed in a feeding mode; if the quantity A is less than or equal to 12ppm and less than or equal to 15ppm and the soft blowing time is not less than 13min after the calcium wire is expected to be fed, the quantity B=20-40 m of the calcium wire is fed to each furnace of molten steel; If the concentration of A is 12< 15ppm and the soft blowing time is less than 13min after the calcium wire is fed, the calcium wire is not fed, and the soft blowing time is mainly kept.
  2. 2. The method for treating calcium abnormality of low-carbon low-silicon aluminum-containing steel according to claim 1, wherein the calcium line is a pure calcium line; After the calcium wire is fed, soft blowing is carried out for 15-25min; the distance between the liquid outlet and the molten steel surface is less than or equal to 800mm when the calcium line is fed.
  3. 3. The method for treating calcium abnormality of low-carbon low-silicon aluminum-containing steel according to claim 1, wherein C is not more than 0.25 wt%, si is not more than 0.10 wt%, S is not more than 0.015 and wt%, and Als is not less than 0.020% and not more than 0.045%.
  4. 4. The method for treating abnormal calcium of low-carbon low-silicon aluminum-containing steel according to claim 1, wherein if the abnormal condition occurs in the Nth furnace (N is more than or equal to 2) after casting, and the stopper rod rises by more than 2mm after casting of the continuous casting feedback ladle, the calcium line quantity fed by the molten steel in the (n+1) th furnace is 190-210m.
  5. 5. A method for producing a low-carbon low-silicon aluminum-containing steel, characterized by comprising the steps of primary refining molten steel, deoxidizing, refining molten steel and performing the calcium abnormality treatment method for the low-carbon low-silicon aluminum-containing steel according to any one of claims 1 to 4 on molten steel, which are performed sequentially.

Description

Method for processing calcium abnormality of low-carbon low-silicon aluminum-containing steel and method for producing low-carbon low-silicon aluminum-containing steel Technical Field The invention relates to the technical field of ferrous metallurgy, in particular to a calcium abnormality treatment method of low-carbon low-silicon aluminum-containing steel and a production method of the low-carbon low-silicon aluminum-containing steel. Background For low-carbon low-silicon aluminum-containing steel, such as SWRCH22A, and the like, because the carbon content and the silicon content are low, the aluminum content is high, and the deoxidization is mainly performed by aluminum, so that the steel has high requirement on the calcium treatment effect, the existing calcium treatment process can effectively control the types and the quantity of inclusions in molten steel by controlling the calcium feeding linear speed, the calcium feeding linear quantity and the like and considering the basic parameters such as the carbon content, the aluminum content, the sulfur content and the like before the calcium feeding, but the basic parameters are common treatment measures under normal conditions, and how to pre-judge and emergency treatment measures are adopted when the calcium treatment effect of certain molten steel is possibly poor so as to reduce the rising condition of a stopper rod caused by the tundish nozzle nodulation, so that the continuous casting of multiple casting furnaces can be successfully completed. Disclosure of Invention The invention aims to provide a calcium abnormality treatment method of low-carbon low-silicon aluminum-containing steel and a production method of low-carbon low-silicon aluminum-containing steel, and the conditions of stopper rising caused by tundish nozzle nodulation are alleviated by adjusting parameters of a calcium treatment step. The invention is realized in the following way: In a first aspect, the invention provides a method for processing calcium abnormality of low-carbon low-silicon aluminum-containing steel, which comprises the steps of feeding calcium wires to molten steel in a bottom argon blowing mode, wherein the method comprises normal production and abnormal processing: Normal production, wherein the feeding amount of the calcium wire is 1.05m-1.35m per ton of molten steel, the feeding linear speed of the calcium wire is 150-250m/min, and the calcium content in the discharged molten steel is 15-25ppm; When any one of the following abnormal conditions occurs, taking a steel sample after feeding the calcium line for 2.5-3.5min to confirm that the calcium content is A, and if the A is less than 15ppm, determining whether to feed the calcium line according to the soft blowing time after the calcium line is expected to be fed; ① Adopting a production mode of aluminum-free steel and low-carbon low-silicon aluminum-containing steel, and casting a2 nd furnace; ② Furnace 1 after new calcium line replacement or furnace 2 after binding calcium line; ③ The distance between the outlet and the molten steel surface is more than 800 mm; ④ When the calcium wire is fed, the obvious splashing times are less than or equal to 2 times, wherein the splashing refers to the phenomenon that the calcium steam floats upwards to bring steel and slag out and is scattered from a ladle opening when the calcium wire is fed, and the obvious splashing refers to the splashing that the distance between the scattered steel flower falling point and the ladle wall is more than or equal to 3 m. In an alternative embodiment, the calcium wire is a pure calcium wire; Preferably, soft blowing is carried out after the calcium wire is fed, and the soft blowing time is 15-25min; preferably, the distance between the liquid outlet and the molten steel surface is less than or equal to 800mm when the calcium wire is fed. In an alternative embodiment, the low carbon low silicon aluminum-containing steel has less than or equal to 0.25wt% C, less than or equal to 0.10wt% Si, less than or equal to 0.015wt% S, and less than or equal to 0.020% Als, less than or equal to 0.045%. In an alternative embodiment, if a <10ppm, immediately feeding the calcium wire, the amount of calcium wire fed per furnace of molten steel b=60/a+150 m; in an alternative embodiment, if A is more than or equal to 10 and less than or equal to 12ppm and the soft blowing time is more than or equal to 13 minutes after the calcium wire is fed in a pre-feeding mode, the quantity B of the calcium wire fed in the feeding mode of molten steel in each furnace is 40-60m; If A is more than or equal to 10 and less than or equal to 12ppm, and the soft blowing time is less than 13min after the calcium wire is fed in a pre-feeding mode, the calcium wire is not fed in a feeding mode. In an alternative embodiment, if 12< A is less than or equal to 15ppm and the soft blowing time is more than or equal to 13min after the calcium wire is expected to be fed, the quantity B