Method for improving production efficiency of Q345B hot rolled narrow strip steel

A technology of production efficiency and narrow strip steel, which is applied in the field of steel rolling, can solve the problems of large temperature loss, large amount of alloy added, and inability to power on to raise temperature, etc.

Active Publication Date: 2019-03-19
LAIWU STEEL YINSHAN SECTION CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

At present, Q345B does not carry out LF refining, and the LF furnace cannot be energized to raise the temperature. Therefore, the high-temperature tapping method of the converter is adopted. The tapping temperature of the converter is not lower than 1670°C. After tapping, the amount of alloy added is large and the temperature loss is large.

Method used

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  • Method for improving production efficiency of Q345B hot rolled narrow strip steel
  • Method for improving production efficiency of Q345B hot rolled narrow strip steel
  • Method for improving production efficiency of Q345B hot rolled narrow strip steel

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0086] Embodiment 1 is the production route of Q345B hot-rolled narrow-strip steel that adopts high Mn and adds a small amount of V microalloying. Embodiment 2 and 3 are the production of Q345B hot-rolled narrow-strip steel that adopts Mn reduction and adds Nb to carry out Nb-V composite microalloying. route.

[0087] Embodiment 1 (comparative example)

[0088] The Q345B hot-rolled narrow steel strip with high Mn and a small amount of V microalloying is used, and its composition range is shown in Table 2:

[0089] Table 2 Component Range

[0090]

[0091] Hot metal pretreatment - top and bottom double blowing converter smelting - strip billet continuous casting - hot rolling.

[0092] The molten iron pretreatment operation process is:

[0093] (1) The molten iron adopts the desulfurization method of injecting magnesium particles. The injection amount of magnesium particles is: 0.3kg / t iron, the sulfur content of the molten iron is controlled below 0.020%, and the desulfu...

Embodiment 2

[0129] The invention provides a production method of a hot-rolled narrow steel strip containing NbQ345B, which is used for reducing the addition of alloy material, improving production efficiency and reducing alloy cost.

[0130] Its ingredients range from:

[0131] Table 4 Component Range

[0132]

[0133]

[0134] The molten iron pretreatment operation process is: (1) The molten iron adopts the desulfurization method of injecting magnesium particles, the injection amount of magnesium particles is: 0.5kg / t iron, the sulfur content of the molten iron is controlled below 0.020%, and the desulfurization slag is removed after desulfurization.

[0135] The converter operation process is:

[0136] (1) The converter is smelted with a single slag process, and the basicity of the final slag is controlled at R=3.2, so that the slag can be melted early at the initial stage, the slag can be melted well in the process, and the final slag can be fully melted.

[0137] The single sl...

Embodiment 3

[0171] The invention provides a production method of a hot-rolled narrow steel strip containing NbQ345B, which is used for reducing the addition of alloy material, improving production efficiency and reducing alloy cost.

[0172] Its ingredients range from:

[0173] Table 6 Component Range

[0174]

[0175] The operation process of molten iron pretreatment is as follows: (1) The molten iron adopts the desulfurization method of injecting magnesium particles, the injection amount of magnesium particles is: 0.4kg / t iron, the sulfur content of molten iron is controlled below 0.020%, and the desulfurization residue is removed after desulfurization.

[0176] The converter operation process is:

[0177] (1) The converter is smelted with a single slag process, and the basicity of the final slag is controlled at R=3.1, so as to achieve early slag melting in the initial stage, good slag melting in the process, and thorough final slag melting.

[0178] The single slag method is as f...

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Abstract

The invention relates to the technical field of steel rolling in the steel metallurgy technology and relates to a method for improving the production efficiency of Q345B hot rolled narrow strip steel.The method includes the following steps that firstly, molten iron pretreatment is conducted; secondly, converter smelting is conducted, wherein the converter steel putting time is not shorter than 2min, when molten steel is discharged by one fifth, calcium silicon, silicon carbide, silicomanganese, vanadium nitrogen and ferroniobium are added in a batched manner for deoxygenation alloying, a carburant is added for increasing carbon, and adding is completed when molten iron is discharged by three fourths; the temperature of a steel ladle is larger than or equal to 700 DEG C, 3 kg/t to 6 kg/tof modification agents are added to the steel ladle bottom before tapping, and then online baking of the steel ladle is conducted; thirdly, bottom argon blowing stirring is conducted in the whole process, argon blowing is conducted for 13 min to 15 min totally, the argon flow is controlled to be 200 L/min to 300 L/min in 10 min before argon blowing, and the argon flow is controlled to be 50 L/minto 80 L/min before departing; fourthly, continuous casting is conducted, protective casting is conducted in the whole process, the superheat degree of tundish molten steel is controlled to range from20 DEG C to 30 DEG C; and fifthly, hot rolling is conducted. By means of the method, an alloy replacing method is used for reducing the adding amount of alloy materials, the converter tapping temperature can be reduced, and therefore the purpose of improving the production efficiency and capacity is achieved.

Description

technical field [0001] The invention relates to the technical field of steel rolling in iron and steel metallurgy technology, in particular to a method for improving the production efficiency of Q345B hot-rolled narrow strip steel. Background technique [0002] With the acceleration of production rhythm, the life of converter lining has become an important factor restricting production and reducing costs. The reason is that in the production of converter steelmaking, the converter lining not only bears the chemical erosion of high-temperature molten steel and slag, but also bears the erosion of molten steel, slag and furnace gas during the smelting process of extremely complex and intense physical and chemical reactions. And the mechanical impact of scrap steel, etc. Therefore, improving the service life of the converter lining is of great significance to improving productivity, increasing furnace life, and increasing economic benefits. [0003] The tapping temperature of ...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C22C38/02C22C38/04C22C38/12C21C7/064C21C5/28C21C7/06C22C33/06C21C7/00C21C7/072B22D11/16B21B37/74
CPCB21B37/74B22D11/16C21C5/28C21C7/0006C21C7/06C21C7/064C21C7/072C22C33/06C22C38/02C22C38/04C22C38/12
Inventor 王利王建军路峰刘洪银亓伟伟王孝科郝帅孙建卫王奉县
Owner LAIWU STEEL YINSHAN SECTION CO LTD
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