阅读说明：本技术 一种控制高牌号硅钢退火产生月牙印缺陷的方法 (Method for controlling crescent mark defects generated by annealing high-grade silicon steel ) 是由 马允敏 秦强波 李冉 张志杰 卢禹龙 于 2021-07-09 设计创作，主要内容包括：本发明涉及一种控制高牌号硅钢退火产生月牙印缺陷的方法,多次调整硅钢退火线入炉及出炉张力参数,使带钢处于预设悬垂量内；本发明避免高速运行下带钢撞在炉辊上,从而产生月牙印缺陷,提高了产品的质量。(The invention relates to a method for controlling the crescent mark defect generated by annealing high-grade silicon steel, which adjusts the tension parameters of the silicon steel annealing line during charging and discharging for many times to ensure that the strip steel is within the preset overhang; the invention avoids the strip steel from impacting the furnace roller under high-speed operation, thereby generating the crescent mark defect and improving the product quality.)

1. A method for controlling the crescent mark defect generated by annealing high-grade silicon steel is characterized by comprising the following steps: and adjusting the tension parameters of the silicon steel annealing line during the feeding and the discharging for a plurality of times to ensure that the strip steel is within the preset overhang amount.

2. The method for controlling the crescent mark defect generated by annealing the high-grade silicon steel according to claim 1, wherein the method comprises the following steps: 40 rolls of 35W440 band steel are selected, when the band steel is annealed, the preset range of the annealing speed is 150 +/-20 m/min, the preset range of the radiation section temperature is 950 +/-20 ℃, and the temperature of the soaking section is controlled to be 980 +/-20 ℃.

3. The method for controlling the crescent mark defect generated by annealing the high-grade silicon steel according to claim 2, wherein the method comprises the following steps: when the strip steel is annealed, the preset tension range of the strip steel entering the furnace is 3.0 +/-0.5 KN, and the dew point in the furnace is less than or equal to 10 ℃.

4. The method for controlling the crescent mark defects generated by annealing of the high-grade silicon steel according to claim 3, wherein the method comprises the following steps: the preset range of the tapping tension is 4.0 +/-0.5 KN.

5. The method for controlling the crescent mark defect generated by annealing the high-grade silicon steel according to claim 1, wherein the method comprises the following steps: selecting 10 rolls of 35W440 strip steel, and annealing the strip steel at the preset annealing speed range of 150 +/-20 m/min, the preset radiation section temperature range of 950 +/-20 ℃ and the soaking section temperature of 980 +/-20 ℃.

6. The method for controlling the crescent mark defects generated by annealing of the high-grade silicon steel according to claim 5, wherein the method comprises the following steps: when the strip steel is annealed, the preset range of the furnace entry tension of the strip steel is 4.0 +/-0.5 KN, and the dew point in the furnace is less than or equal to 10 ℃.

7. The method for controlling the crescent mark defect generated by annealing the high-grade silicon steel according to claim 6, wherein the method comprises the following steps: the preset range of the tapping tension is 8.0 +/-0.5 KN.

Technical Field

The invention relates to a method for controlling the defect of crescent moon mark generated by annealing high-grade silicon steel, belonging to the technical field of material processing engineering.

Background

The silicon steel continuous annealing unit mainly ensures the controllable product quality and the continuous and stable production through the process temperature control and the tension control, wherein the tension control in the furnace is the key point of influencing the high-speed stable production of a continuous annealing line, particularly the tension control difficulty is increased when producing 0.35 series high marks, the tension fluctuation in the furnace is increased, particularly in a micro-tension control mode, the suspension amount between furnace rollers is increased, the suspended strip steel is easy to collide with the furnace rollers under the high-speed operation to generate the crescent mark defect, and meanwhile, the strip steel is easy to deviate and scrape the edge under the micro-tension to force the unit to reduce the speed, thereby seriously influencing the production efficiency.

In the prior art, for example, application No. 201811329336.7 discloses a method for controlling the quality of a high-grade silicon steel casting blank, which mainly includes some improvements on silicon steel components, and the limitations on conditions in the implementation process are combined, but the method is high in cost, so that a method capable of improving the product quality and avoiding the generation of a crescent moon mark defect is urgently needed.

Disclosure of Invention

The invention provides a method for controlling the crescent mark defect generated by annealing high-grade silicon steel, which ensures that strip steel is in a proper suspension amount, avoids the phenomenon that the strip steel collides with a furnace roller under high-speed operation, thereby generating the crescent mark defect and improving the product quality.

The technical scheme adopted by the invention for solving the technical problems is as follows:

a method for controlling the crescent mark defect generated by annealing high-grade silicon steel comprises the steps of repeatedly adjusting tension parameters of a silicon steel annealing line during charging and discharging so as to enable strip steel to be within a preset overhang amount;

as a further optimization of the invention, 40 rolls of 35W 440-type strip steel are selected, when the strip steel is annealed, the preset range of the annealing speed is 150 +/-20 m/min, the preset range of the radiation section temperature is 950 +/-20 ℃, and the temperature of the soaking section is controlled to be 980 +/-20 ℃;

as a further optimization of the invention, when the strip steel is annealed, the preset range of the furnace entry tension of the strip steel is 3.0 plus or minus 0.5KN, and the dew point in the furnace is less than or equal to 10 ℃;

as a further preference of the invention, the preset range of tapping tension is 4.0 +/-0.5 KN;

as further optimization of the invention, 10 rolls of 35W 440-type strip steel are selected, when the strip steel is annealed, the preset range of annealing speed is 150 +/-20 m/min, the preset range of radiation section temperature is 950 +/-20 ℃, and the temperature of a soaking section is controlled to be 980 +/-20 ℃;

as a further optimization of the invention, when the strip steel is annealed, the preset range of the furnace entry tension of the strip steel is 4.0 plus or minus 0.5KN, and the dew point in the furnace is less than or equal to 10 ℃;

as a further preferred aspect of the present invention, the tapping tension is within a predetermined range of 8.0. + -. 0.5 KN.

Through the technical scheme, compared with the prior art, the invention has the following beneficial effects:

aiming at high-grade strip steel with different coil numbers, the invention only needs to set the annealing process speed, the radiation section temperature and the soaking section temperature and limit the furnace entering tension and the furnace discharging tension, thereby realizing the improvement of the product quality.

Drawings

The invention is further illustrated with reference to the following figures and examples.

FIG. 1 is a schematic view of a crescent moon shape on the surface of a finished product;

FIG. 2 is a crescent morphology formed when the surface of the finished product is detected by a surface detector.

Detailed Description

The present invention will now be described in further detail with reference to the accompanying drawings. In the description of the present application, it is to be understood that the terms "left side", "right side", "upper part", "lower part", etc., indicate orientations or positional relationships based on those shown in the drawings, and are only for convenience of describing the present invention and simplifying the description, but do not indicate or imply that the referred device or element must have a specific orientation, be constructed in a specific orientation, and be operated, and that "first", "second", etc., do not represent an important degree of the component parts, and thus are not to be construed as limiting the present invention. The specific dimensions used in the present example are only for illustrating the technical solution and do not limit the scope of protection of the present invention.

When 0.35 series high marks are produced, because the tension control difficulty is increased, the fluctuation of the tension in the furnace is increased, particularly, under a micro-tension control mode, the suspension amount between the furnace rollers is increased, and the suspended strip steel under high-speed operation is easy to collide with the furnace rollers to generate a crescent mark defect; in order to solve the above problems, the present application provides a method that can control the generation of the crescent defect, which contributes to the stable production of the annealing line, thereby improving the yield, quality and reducing the synergy.

Example 1:

the method and the control measure related by the application are utilized to produce 35W440 strip steel in a certain steel mill silicon steel annealing unit, 40 coils are counted, and the specification of a finished product is 0.35 x 1230 mm.

The related control parameters are as follows:

the speed of the annealing process is controlled to be 150 +/-20 m/min, the temperature of the radiation section is controlled to be 950 +/-20 ℃, the temperature of the soaking section is controlled to be 980 +/-20 ℃, the tension of the furnace entering is controlled to be 3.0 +/-0.5 KN, the dew point in the furnace is less than or equal to 10 ℃, and the tension of the furnace discharging is controlled to be 4.0 +/-0.5 KN.

And (4) conclusion: the surface quality of the strip steel is detected by a surface detector, the quality of the plate surface is good, the crescent seal defect is not found, the online iron loss curve is normal, and the surface quality and the performance after annealing can meet the requirements of internal control standards.

In order to better show that the method can avoid the crescent seal defect, a comparative example is also made during the experiment, the method and the control measure related by the invention are utilized to produce 35W440 strip steel in a silicon steel annealing unit of a certain steel mill, 10 coils are counted, and the specification of a finished product is 0.35 x 1230 mm.

The related control parameters are as follows:

the speed of the annealing process is controlled at 150 +/-20 m/min, the temperature of the radiation section is controlled at 950 +/-20 ℃, the temperature of the soaking section is controlled at 980 +/-20 ℃, the tension of the furnace is controlled at 4.0 +/-0.5 KN, the dew point in the furnace is less than or equal to 10 ℃, and the tension of the furnace is controlled at 8.0 +/-0.5 KN.

And (4) conclusion: the surface quality of the strip steel is detected through a surface detector, the crescent print defect appears on the surface of 3 continuous rolls, the online iron loss curve of the crescent print defect is normal, as shown in fig. 1 and fig. 2, the crescent morphology directly observed on the surface of a finished product and the crescent morphology detected through the surface detector are respectively the crescent print defect, and the finished product judgment processing is carried out.

It will be understood by those skilled in the art that, unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the prior art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

The meaning of "and/or" as used herein is intended to include both the individual components or both.

The term "connected" as used herein may mean either a direct connection between components or an indirect connection between components via other components.

In light of the foregoing description of the preferred embodiment of the present invention, many modifications and variations will be apparent to those skilled in the art without departing from the spirit and scope of the invention. The technical scope of the present invention is not limited to the content of the specification, and must be determined according to the scope of the claims.