Strip steel austenite signal detection system

Abstract

The utility model discloses a strip steel austenite signal detection system. The system comprises an X-ray light source, a collimator, a first vacuum pipeline, a second vacuum pipeline and a two-dimensional detector. The X-ray light source is used for generating X-rays through excitation of a heavy metal target material, the collimator is used for carrying out beam collection on the X-rays, and the first vacuum pipeline is used for being arranged in the annealing furnace. And the second vacuum pipeline is arranged in the annealing furnace. The two-dimensional detector is arranged on one side of the fourth transmission opening of the second vacuum pipeline, and the fourth transmission opening faces the surface of the two-dimensional detector. X-rays generated by the X-ray light source pass through a beam set of the collimator, are transmitted to the strip steel through the first vacuum pipeline and are diffracted on the second surface of the strip steel to form a diffraction signal, and the diffraction signal is used for determining austenite content information of the strip steel. According to the method and the device, the diffraction signal of the X-ray in the strip steel can be detected on line, so that data support is provided for subsequently determining austenite content information in the strip steel.

Description

Technical Field

[0001] This application belongs to the field of strip steel inspection technology, and in particular relates to a strip steel austenite signal detection system. Background Technology

[0002] In the cold rolling annealing process of strip steel production, the strip is first heated to austenitize or partially austenitize, and then slowly cooled to achieve a predetermined ratio of austenite to ferrite. This austenite to ferrite ratio determines the amount of martensite formed during subsequent rapid cooling, thus affecting product performance. Therefore, it is necessary to monitor the austenite content during slow cooling.

[0003] However, on the annealing production line, the strip steel is located inside the annealing furnace. In the high-temperature environment, the detectors and light sources are difficult to operate, making it difficult to detect the austenite signal in the strip steel online. Utility Model Content

[0004] The embodiments of this application provide a strip steel austenite signal detection system, which can at least to some extent realize online detection of X-ray diffraction signals in strip steel, thereby providing data support for subsequent determination of austenite content information in strip steel.

[0005] Other features and advantages of this application will become apparent from the following detailed description, or may be learned in part from practice of this application.

[0006] According to a first aspect of the embodiments of this application, a strip austenite signal detection system is provided, wherein the strip runs in an annealing furnace, the annealing furnace including an upper furnace wall and a lower furnace wall, the upper furnace wall having a first opening, and the lower furnace wall having a second opening, the system comprising:

[0007] An X-ray source and a collimator are provided. The X-ray source is used to generate X-rays by excitation with a heavy metal target. The collimator is disposed on one side of the X-ray source and is used to focus the X-rays. The light output direction of the collimator is towards the first opening.

[0008] A first vacuum pipe, wherein the collimator is disposed between the first vacuum pipe and the X-ray source, the first vacuum pipe is used to be disposed in the annealing furnace, and includes a first transmission port and a second transmission port, the first transmission port facing the first opening and being disposed opposite to the collimator, and the second transmission port facing the first surface of the strip.

[0009] A second vacuum pipe is provided inside the annealing furnace. The second vacuum pipe includes a third transmission port and a fourth transmission port. The third transmission port faces the second surface of the strip steel. The second surface is disposed opposite to the first surface.

[0010] A two-dimensional detector is disposed on one side of the fourth transmission port, with the fourth transmission port facing the surface of the two-dimensional detector;

[0011] The X-rays generated by the X-ray source are focused by the collimator and then transmitted to the strip steel through the first vacuum pipe. They are diffracted on the second surface of the strip steel to form a diffraction signal. The two-dimensional detector is used to detect the diffraction signal, and the diffraction signal is used to determine the austenite content information of the strip steel.

[0012] Optionally, the light emission direction of the collimator and the length direction of the first vacuum pipe are perpendicular to the first surface of the strip.

[0013] Optionally, it also includes:

[0014] A first housing, wherein the X-ray source and the collimator are disposed inside the first housing, and a third opening is provided on the first housing, the third opening being disposed opposite to the first transmission port.

[0015] Optionally, the outer wall of the first housing and / or the second housing is provided with a water-cooling module.

[0016] Optionally, the length direction of the second vacuum pipe has a target angle with the normal to the second surface of the strip, and the target angle is substantially consistent with the diffraction angle of the X-rays on the second surface of the strip.

[0017] Optionally, the vacuum level of the first vacuum pipe and the second vacuum pipe is less than or equal to 20 Pa; and / or

[0018] The heat resistance of the first vacuum pipe and the second vacuum pipe is greater than or equal to 800 degrees Celsius.

[0019] Optionally, the first vacuum conduit includes a first tube wall facing the first opening and a second tube wall facing the first surface of the strip steel, wherein the first tube wall and the second tube wall are provided with a light-transmitting medium to form the first transmission port and the second transmission port;

[0020] The second vacuum conduit includes a third tube wall facing the second surface of the strip steel and a fourth tube wall facing the surface of the two-dimensional detector. The third tube wall and the fourth tube wall are provided with a light-transmitting medium to form the third transmission port and the fourth transmission port.

[0021] Optionally, the first and second pipe walls are provided with beryllium metal, the third pipe wall is provided with beryllium metal, and the fourth pipe wall is provided with a polyimide film or an aluminum film.

[0022] Optionally, the X-rays have a penetration rate in the strip greater than or equal to 20%.

[0023] Optionally, the thickness of the strip steel can be in the range of 0.5mm-2.5mm.

[0024] The present invention provides one or more technical solutions that achieve at least the following technical effects or advantages:

[0025] This application provides a strip austenite signal detection system. The strip runs inside an annealing furnace, which includes an upper furnace wall and a lower furnace wall. The upper furnace wall has a first opening, and the lower furnace wall has a second opening. The system includes an X-ray source, a collimator, a first vacuum pipe, a second vacuum pipe, and a two-dimensional detector. The X-ray source is used to generate X-rays by exciting a heavy metal target. The collimator is disposed on one side of the X-ray source to focus the X-rays, and the output direction of the collimator faces the first opening. The collimator is disposed between the first vacuum pipe and the X-ray source. The first vacuum pipe is disposed inside the annealing furnace and includes a first transmission port and a second transmission port. The first transmission port faces the first opening and is disposed opposite to the collimator, while the second transmission port faces the first surface of the strip. The second vacuum pipe is disposed inside the annealing furnace and includes a third transmission port and a fourth transmission port. The third transmission port faces the second surface of the strip, which is disposed opposite to the first surface. The two-dimensional detector is disposed on one side of the fourth transmission port, and the fourth transmission port faces the surface of the two-dimensional detector. In this application, X-rays generated by the X-ray source are focused by the collimator and transmitted to the strip steel through the first vacuum pipe. The X-rays diffract on the second surface of the strip steel, forming a diffraction signal. The two-dimensional detector detects this diffraction signal, which is used to determine the austenite content of the strip steel. Therefore, this application overcomes the problem of the X-ray source and two-dimensional detector being unable to operate at high temperatures by placing the X-ray source and two-dimensional detector outside the annealing furnace and utilizing the first and second vacuum pipes to reduce X-ray attenuation and extend the optical path. This allows for online detection of the X-ray diffraction signal in the strip steel, providing data support for subsequent determination of the austenite content in the strip steel.

[0026] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and do not limit this application. Attached Figure Description

[0027] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application. It is obvious that the drawings described below are merely some embodiments of this application, and those skilled in the art can obtain other drawings based on these drawings without any inventive effort. In the drawings:

[0028] Figure 1 A structural diagram of the austenite signal detection system for strip steel according to an embodiment of this application is shown.

[0029] Among them, 11-X-ray source; 12-collimator; 2-first vacuum pipe; 3-second vacuum pipe; 4-two-dimensional detector; 5-annealing furnace; 6-strip steel. Detailed Implementation

[0030] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0031] Furthermore, the described features, structures, or characteristics can be combined in any suitable manner in one or more embodiments. Numerous specific details are provided in the following description to give a thorough understanding of embodiments of this application. However, those skilled in the art will recognize that the technical solutions of this application can be practiced without one or more of the specific details, or other methods, components, apparatuses, steps, etc., can be employed. In other instances, well-known methods, apparatuses, implementations, or operations are not shown or described in detail to avoid obscuring various aspects of this application.

[0032] The block diagrams shown in the accompanying drawings are merely functional entities and do not necessarily correspond to physically independent entities. That is, these functional entities can be implemented in software, in one or more hardware modules or integrated circuits, or in different models and / or processor devices and / or microcontroller devices.

[0033] The flowcharts shown in the accompanying drawings are merely illustrative and do not necessarily include all content and operations / steps, nor do they necessarily need to be performed in the described order. For example, some operations / steps can be broken down, while others can be combined or partially combined; therefore, the actual execution order may change depending on the specific circumstances.

[0034] It should also be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such uses of these terms can be interchanged where appropriate so that the embodiments of this application described herein can be implemented in orders other than those illustrated or described.

[0035] In strip steel production, such as high-strength steels like DP, DH, CP, TR, IP, and QP, the cold rolling and annealing process requires initial heating for austenitization or partial austenitization, followed by slow cooling to achieve a predetermined austenite-to-ferrite ratio. Rapid cooling then occurs to induce martensitic transformation of the austenite. The ferrite-to-austenite ratio in the strip before rapid cooling determines the amount of martensite formed during this process, thus affecting the strip's final properties. Therefore, to ensure stable product quality for high-strength steel, it is necessary to monitor the ferrite-to-austenite ratio at the end of the slow cooling phase online. This allows for real-time adjustment of the fan power in the slow cooling section, ensuring a stable phase composition for strips of the same steel grade and specifications.

[0036] Since austenite and ferrite in steel strip are allotropes, differing only in their crystal structure, the ratio of austenite to ferrite in steel is typically measured using X-ray crystal diffraction. At room temperature, the YB / T 5338-2019 standard, "Quantitative Determination of Austenite in Steel by X-ray Diffraction," can be used, employing a cobalt or copper target as the light source to measure the austenite content in a stationary sample offline via reflection.

[0037] However, on continuous annealing production lines, the strip steel is inside the furnace, limiting the detection space; in the high-temperature environment, two-dimensional detectors and light sources cannot operate; furthermore, the strip steel is in high-speed motion, and vertical shaking is unavoidable, making it difficult to meet the diffraction geometry required by the conventional YB / T 5338-2019 detection method. Therefore, conventional methods are insufficient for online detection of austenite content information in high-temperature strip steel.

[0038] In view of this, embodiments of this application provide a strip steel austenite signal detection system. This system can at least to some extent overcome the problem that X-ray sources and two-dimensional detectors cannot work at high temperatures. This application enables online detection of X-ray diffraction signals in strip steel, thereby providing data support for subsequent determination of austenite content information in strip steel.

[0039] The austenite signal detection system for strip steel according to an embodiment of this application will be described below with reference to the accompanying drawings.

[0040] Figure 1 A schematic diagram of the structure of the austenitic strip detection system according to an embodiment of this application is shown.

[0041] According to a first aspect of this application, a strip steel austenite signal detection system is provided, comprising: an X-ray source 11, a collimator 12, a first vacuum pipe 2, a second vacuum pipe 3, and a two-dimensional detector 4. The X-ray source 11 is used to generate X-rays by excitation with a heavy metal target. The collimator 12 is disposed on one side of the X-ray source 11 for focusing the X-rays, and the light emission direction of the collimator 12 faces the first opening. The collimator 12 is disposed between the first vacuum pipe 3 and the X-ray source 11. The first vacuum pipe 2 is disposed within an annealing furnace and includes a first transmission port and a second transmission port. The first transmission port faces the first opening and is disposed opposite to the collimator 12, and the second transmission port faces the first surface of the strip steel 6. The second vacuum pipe 3 is disposed within the annealing furnace and includes a third transmission port and a fourth transmission port. The third transmission port faces the second surface of the strip steel 6, and the second surface is disposed opposite to the first surface. The two-dimensional detector 4 is disposed on one side of the fourth transmission port, and the fourth transmission port faces the surface of the two-dimensional detector 4. The X-rays generated by the X-ray source 11 are focused by the collimator 12 and transmitted to the strip steel 6 through the first vacuum pipe 2. They are diffracted on the second surface of the strip steel 6 to form a diffraction signal. The two-dimensional detector 4 is used to detect the diffraction signal and the diffraction signal is used to determine the austenite content information of the strip steel 6.

[0042] It should be noted that the working principle of the strip austenite signal detection system in this embodiment is as follows: The X-rays generated by the X-ray source 11 are focused by the collimator 12 and transmitted directly to the first transmission port of the first vacuum pipe 2. For example, the X-ray source 11 is powered by a 60kV high-voltage power supply, which acts on a heavy metal target source, such as a tungsten target, thereby generating highly penetrating X-rays and transmitting them to the first vacuum pipe 2. The first vacuum pipe 2 irradiates the surface of the strip 6 with X-rays that penetrate the entire strip 6. After penetrating the strip 6, diffraction occurs on the second surface of the strip. The diffraction signal can carry information such as the microstructure and the content of each phase in the strip 6. The diffraction signal is transmitted to the two-dimensional detector 4 by the second vacuum pipe 3. Thus, the two-dimensional detector 4 can detect the diffraction signal. This diffraction signal can provide data support for subsequently determining the austenite content in the strip 6.

[0043] Therefore, by placing the X-ray source 11 and the two-dimensional detector 4 outside the annealing furnace 5, and by using the first vacuum pipe 2 and the second vacuum pipe 3 to reduce the attenuation during X-ray transmission and extend the optical path, this application overcomes the problem that the X-ray source 11 and the two-dimensional detector 4 cannot work at high temperatures. This application enables online detection of the diffraction signal of X-rays in the strip steel 6, thereby providing data support for the subsequent determination of the austenite content information in the strip steel 6.

[0044] Understandably, when installing the austenitic signal detection system for strip 6, a first opening ("skylight") can be made in the upper furnace wall of the annealing furnace 5. An X-ray source 11 and a collimator 12 can be installed outside the first opening (the X-ray source 11 and collimator 12 can be encapsulated in a housing, but the light emission direction is directly facing the first opening). Then, a first vacuum pipe 2 is installed between the first opening and the first surface of strip 6, and the first transmission port of the first vacuum pipe 2 can be directly aligned with the collimator 12. In addition, a second opening is made in the lower furnace wall of the annealing furnace 5, and a two-dimensional detector 4 is installed on one side of the lower furnace wall. The second opening faces the two-dimensional detector 4, and a second vacuum pipe 3 is installed between the second opening and the second surface of strip 6. The fourth transmission port of the second vacuum pipe 3 can correspond to the signal detection position of the two-dimensional detector 4.

[0045] Understandably, the collimator 12 can improve the light output efficiency of the X-ray source 11, so that as many X-rays emitted by the X-ray source 11 as possible enter the first vacuum pipe 2, and thus allow the focused X-rays to enter the annealing furnace 5 through the first vacuum pipe 2 without attenuation.

[0046] In some embodiments, the light emission direction of the collimator 12 and the length direction of the first vacuum pipe 2 are perpendicular to the first surface of the strip steel 6.

[0047] Thus, X-rays are perpendicularly irradiated onto the first surface of strip 6 and penetrate the entire strip 6. After penetrating strip 6, they diffract on the second surface of strip 6, forming a diffraction signal. The diffraction signal carries information such as the microstructure and content of each phase of strip 6, thereby providing data support for subsequent austenite content measurement.

[0048] In some embodiments, the two-dimensional detector 4 is rectangular in shape, and the two-dimensional detector 4 has a dimension greater than or equal to 75 mm in at least one direction.

[0049] In some embodiments, the device further includes: a first housing, in which the X-ray source 11 and the collimator 12 are disposed, and a third opening is provided on the first housing, the third opening being disposed opposite to the first transmission port; and a second housing, in which the two-dimensional detector 4 is disposed.

[0050] In some embodiments, the outer wall of the first housing and / or the second housing is provided with a water-cooling module.

[0051] Understandably, due to the high temperature near the annealing furnace 5, encapsulating the X-ray source 11 and collimator 12 within the first housing improves their safety. The first housing provides space for accommodating the X-ray source 11 and collimator 12, as well as a signal line outlet (third opening), and can be securely connected to the furnace wall of the annealing furnace 5 at the first opening. Similarly, encapsulating the two-dimensional detector 4 within the second housing improves its safety. Both the first and second housings can be made of radiation-resistant and heat-resistant materials to prevent X-ray leakage. The exterior of both housings is equipped with a circulating water-cooling module, ensuring that the internal temperature of both housings remains stable below 25°C during operation, thus preventing the X-ray source 11, collimator 12, and two-dimensional detector 4 from operating in high-temperature environments and avoiding issues such as high-temperature failure.

[0052] In some embodiments, the length direction of the second vacuum pipe 3 has a target angle with the normal to the second surface of the strip 6, and the target angle is substantially consistent with the diffraction angle of the X-rays on the second surface of the strip 6.

[0053] It is understandable that X-rays will diffract within the strip 6 and on its second surface, resulting in an angular offset between the diffracted signal lines and the X-rays incident on the strip 6. Therefore, to receive the diffracted signal as completely as possible, the second vacuum pipe 3 is tilted, meaning that the length direction of the second vacuum pipe 3 forms a target angle β with the second surface of the strip 6. The angle β can be consistent with the diffraction angle α of the X-rays on the second surface of the strip 6, for example, 6°-10°, such as 6°, 7°, 8°, 9°, 10°, etc., depending on the properties of the strip 6, and is not limited here.

[0054] In some embodiments, the vacuum level of the first vacuum pipe 2 and the second vacuum pipe 3 is less than or equal to 20 Pa, thereby enabling the incident X-rays and the outgoing diffraction signals to be transmitted with as little loss and attenuation as possible.

[0055] In some embodiments, the first vacuum pipe 2 and the second vacuum pipe 3 can be made of high-temperature resistant metal pipes, and the heat resistance of the first vacuum pipe 2 and the second vacuum pipe 3 is greater than or equal to 800 degrees Celsius.

[0056] In some embodiments, the first vacuum conduit 2 includes a first wall facing the first opening and a second wall facing the first surface of the strip steel 6, the first wall and the second wall being provided with a light-transmitting medium to form the first transmission port and the second transmission port; the second vacuum conduit 3 includes a third wall facing the second surface of the strip steel 6 and a fourth wall facing the surface of the two-dimensional detector, the third wall and the fourth wall being provided with a light-transmitting medium to form the third transmission port and the fourth transmission port.

[0057] It is understandable that a light-transmitting medium can have the characteristics of being heat-resistant and not reflecting, refracting, or attenuating X-rays.

[0058] In some embodiments, the first and second pipe walls are provided with beryllium metal, the third pipe wall is provided with beryllium metal, and the fourth pipe wall is provided with a polyimide (PI) film or an aluminum (Al) film.

[0059] Understandably, beryllium, polyimide, or aluminum films possess high light transmittance, meaning their X-ray transmittance is greater than or equal to a preset value, such as 95%, 96%, 97%, 98%, 99%, or 100%. This further ensures that the incident X-rays and the emitted diffraction signals are transmitted with as little loss or attenuation as possible.

[0060] In some embodiments, the two-dimensional detector 4 is used for:

[0061] The intensity and distribution of the diffraction signal are detected to generate an electronic image containing the microstructure information of the strip 6.

[0062] It is understood that the two-dimensional detector 4 can be a two-dimensional array two-dimensional detector, which can detect the intensity and distribution of the diffraction signal and automatically generate an electronic image containing the microstructure information of the strip steel 6. The specific detection principle can be found in existing related technologies and will not be elaborated here. This electronic image can then be transmitted to a processing terminal, where the terminal obtains austenite content information, such as the ferrite / austenite ratio in the strip steel 6, based on the electronic image. In other words, the diffraction signal detected by the austenite signal detection system of the strip steel 6 in this embodiment can provide data support for subsequently determining the ferrite / austenite ratio in the strip steel 6.

[0063] In some embodiments, the thickness of the strip 6 in this application embodiment ranges from 0.5mm to 2.5mm, for example, 0.5mm, 0.6mm, 1.0mm, 1.5mm, 2.0mm, 2.5mm, etc.

[0064] In some embodiments, the X-rays transmitted from the first vacuum conduit 2 to the strip 6 have a penetration rate greater than or equal to 22%.

[0065] Therefore, the austenite signal detection system for strip steel 6 in this embodiment has a simple instrument configuration. The high-penetration X-rays penetrate the strip steel 6, eliminating the inhomogeneity of the microstructure along its thickness and preventing the influence of local microstructure and defects on the overall measurement results. The short wavelength and small Bragg angle of the X-rays allow a single two-dimensional detector to obtain a complete diffraction signal, thus ignoring the positional deviation of the diffraction beam caused by steel plate vibration and thickness variations. Furthermore, the two vacuum channels reduce X-ray attenuation, thereby extending the optical path and enabling the light source and two-dimensional detector to operate normally under high-temperature radiation conditions. This embodiment provides reliable data support for the microstructure ratio control of cold-rolled multiphase steel products.

[0066] The above description is merely an embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of the claims of this application.

Claims

1. A strip steel austenite signal detection system, characterized in that, The strip steel runs inside an annealing furnace, which includes an upper furnace wall and a lower furnace wall. The upper furnace wall has a first opening, and the lower furnace wall has a second opening. The system includes: An X-ray source and a collimator are provided. The X-ray source is used to generate X-rays by excitation with a heavy metal target. The collimator is disposed on one side of the X-ray source and is used to focus the X-rays. The light output direction of the collimator is towards the first opening. A first vacuum pipe, wherein the collimator is disposed between the first vacuum pipe and the X-ray source, the first vacuum pipe is used to be disposed in the annealing furnace, and includes a first transmission port and a second transmission port, the first transmission port facing the first opening and being disposed opposite to the collimator, and the second transmission port facing the first surface of the strip. A second vacuum pipe is provided inside the annealing furnace. The second vacuum pipe includes a third transmission port and a fourth transmission port. The third transmission port faces the second surface of the strip steel. The second surface is disposed opposite to the first surface. A two-dimensional detector is disposed on one side of the fourth transmission port, with the fourth transmission port facing the surface of the two-dimensional detector; In this process, the X-rays generated by the X-ray source are focused by the collimator and then transmitted to the strip steel through the first vacuum pipe. The X-rays diffract on the second surface of the strip steel, forming a diffraction signal. The two-dimensional detector detects this diffraction signal, which is used to determine the austenite content of the strip steel. 。 2. The system according to claim 1, characterized in that, The light emission direction of the collimator and the length direction of the first vacuum pipe are perpendicular to the first surface of the strip.

3. The system according to claim 1, characterized in that, Also includes: A first housing, wherein the X-ray source and the collimator are disposed inside the first housing, and a third opening is provided on the first housing, the third opening being disposed opposite to the first transmission port; The second housing contains the two-dimensional detector.

4. The system according to claim 3, characterized in that, The outer wall of the first housing and / or the second housing is provided with a water-cooling module.

5. The system according to claim 1, characterized in that, The second vacuum pipe has a target angle between its length direction and the normal to the second surface of the strip, and the target angle is substantially consistent with the diffraction angle of the X-rays on the second surface of the strip.

6. The system according to claim 1, characterized in that, The vacuum level in the first vacuum pipe and the second vacuum pipe is less than or equal to 20 Pa; and / or The heat resistance of the first vacuum pipe and the second vacuum pipe is greater than or equal to 800 degrees Celsius.

7. The system according to claim 1, characterized in that, The first vacuum conduit includes a first tube wall facing the first opening and a second tube wall facing the first surface of the strip steel. The first tube wall and the second tube wall are provided with a light-transmitting medium to form the first transmission port and the second transmission port. The second vacuum conduit includes a third tube wall facing the second surface of the strip steel and a fourth tube wall facing the surface of the two-dimensional detector. The third tube wall and the fourth tube wall are provided with a light-transmitting medium to form the third transmission port and the fourth transmission port.

8. The system according to claim 7, characterized in that, The first and second pipe walls are provided with beryllium metal, the third pipe wall is provided with beryllium metal, and the fourth pipe wall is provided with a polyimide film or an aluminum film.

9. The system according to claim 1, characterized in that, The X-rays have a penetration rate of 20% or greater in the strip.

10. The system according to any one of claims 1-9, characterized in that, The thickness of the strip steel ranges from 0.5mm to 2.5mm.

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