High-temperature low-acid-consumption pickling cold rolling process for silicon steel strip

Abstract

The invention relates to the technical field of silicon steel production and processing, in particular to a high-temperature low-acid-consumption acid pickling and cold rolling process for a silicon steel strip. According to the method, low-concentration hydrochloric acid is combined with high-temperature pickling to enhance the reaction activity, and the consumption of hydrochloric acid can be greatly reduced on the premise of ensuring the oxide scale removal effect; meanwhile, the corrosivity of low-concentration hydrochloric acid to equipment is reduced, and the maintenance cost of the equipment can be saved; two-section gradient concentration pickling is matched with a high-temperature process, the oxide scale is efficiently removed layer by layer, the process can be optimized in real time according to the actual residual quantity in combination with self-adaptive adjustment of pickling parameters, and the pickling effect is remarkably improved; the rough rolling descaling pass is added before the follow-up cold rolling procedure, so that residual oxide scale can be thoroughly removed; the pickling parameters are adaptively adjusted according to the amount of residual oxide scales on the surface of the steel strip, pickling effect fluctuation caused by the difference of the oxide scales of raw materials can be effectively avoided, and the stability of the production process and the product percent of pass are ensured.

Description

Technical Field

[0001] This invention relates to the field of silicon steel production and processing technology, specifically to a high-temperature, low-acid-consumption pickling and cold rolling process for silicon steel strip. Background Technology

[0002] Silicon steel strip is a key material in the power and electronics industries, and its surface quality directly determines the performance of the final product. A layer of iron oxide scale forms on the surface of silicon steel coils produced by hot rolling mills. This scale is mainly composed of various iron oxides. If the iron oxide scale is not effectively removed before the cold rolling process, it will not only severely affect the surface smoothness and flatness of the steel strip, but also cause scratches and wear on the work rolls during cold rolling, reducing the service life of the work rolls, increasing production costs, and potentially leading to defects such as cracks and inclusions in the cold-rolled products, affecting their mechanical and magnetic properties.

[0003] Currently, the industry commonly uses hydrochloric acid pickling to remove iron oxide scale from the surface of silicon steel coils, with conventional process parameters of 15-21% hydrochloric acid concentration and pickling temperature of 50-60℃. However, this process has significant drawbacks: firstly, the use of high-concentration hydrochloric acid leads to high pickling costs, and the stronger corrosiveness of high-concentration hydrochloric acid places higher demands on the corrosion resistance of pickling equipment, increasing equipment maintenance costs; secondly, even with high-concentration hydrochloric acid, it is still difficult to completely remove iron oxide scale from some silicon steel coils with thick or dense surface structures. The residual iron oxide scale, after entering the cold rolling process, will still adversely affect product quality and work rolls. In addition, the waste acid solution generated during high-concentration hydrochloric acid pickling has a high content of acidic substances, making subsequent treatment difficult and costly, which is inconsistent with the current industry development trend of green production, energy conservation, and emission reduction. Therefore, developing a low-acid-consumption, high-efficiency, and high-quality silicon steel strip pickling and cold rolling process has become an urgent technical problem to be solved in the industry. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a high-temperature, low-acid-consumption pickling and cold rolling process for silicon steel strip. By optimizing the pickling process parameters and coordinating them with the cold rolling process, the process can reduce hydrochloric acid consumption and production costs while achieving efficient removal of iron oxide scale, thus ensuring the surface quality and overall performance of the cold-rolled silicon steel strip.

[0005] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows: A high-temperature, low-acid-consumption pickling and cold-rolling process for silicon steel strip mainly includes the following steps: Step S1, Hot-rolled coil preparation: Select the hot-rolled silicon steel strip as raw material and test the thickness of the iron oxide scale and the composition of the oxide layer on its surface; Step S2, Two-stage high-temperature low-concentration pickling: The silicon steel strip raw material is subjected to gradient high-temperature low-concentration continuous pickling using a two-stage shallow tank turbulent hydrochloric acid pickling device, wherein the two acid tanks in the pickling device are arranged in series. Step S3, Adaptive adjustment of pickling parameters: Real-time detection of the amount of residual iron oxide scale on the surface of the silicon steel strip after pickling, combined with the preset residual iron oxide scale threshold, adaptive adjustment of the pickling parameters of the hydrochloric acid pickling device; Step S4, Collaborative cold rolling process: The rough rolling descaling process is used to completely remove the residual iron oxide scale on the surface of the silicon steel strip, and then the fine rolling forming process is used to cold roll the silicon steel strip to the target thickness.

[0006] The gradient high-temperature low-concentration continuous pickling specifically includes: S11, Acid concentration control: The two acid tanks adopt a gradient increase in acid concentration. The initial concentration of hydrochloric acid in acid tank 1 is controlled at L1, and the initial concentration of hydrochloric acid in acid tank 2 is controlled at L2, and L1 < L2. S12, pickling temperature control: Based on the preset initial heating rate V0 and preset time interval t1, the acid temperature of the two acid tanks is increased to temperature T in a stepped heating manner. S13, Pickling time and speed control: Based on the acid concentration and pickling temperature in the two acid tanks, and combined with the iron oxide scale thickness h detected in step S1, determine the total pickling time and corresponding pickling speed of the two acid tanks. S14, Acid Replacement Frequency Control: Replace the acid in the two acid tanks according to the preset initial acid replacement frequency W0.

[0007] Furthermore, the total pickling time t of the two acid tanks is calculated as follows:

[0008] In the formula, K is the reaction correction coefficient, and C1 and C2 are the reaction weight coefficients of acid tank No. 1 and acid tank No. 2, respectively.

[0009] Furthermore, the pickling rate v is calculated as follows:

[0010] In the formula, D is the total length of the two acid tanks.

[0011] Furthermore, the initial acid replacement frequency W0 is calculated and determined based on the increase in iron salt content of the acid solution in the two acid tanks within a preset time interval t2.

[0012] Furthermore, the adaptive adjustment of the pickling parameters specifically includes: 1) When the thickness of residual iron oxide scale detected is >2μm, If the residual amount is in the range of 2-3μm, the acid concentration in the two acid tanks will be increased by 0.5% respectively, while keeping the heating rate unchanged and increasing the acid replacement frequency by 5%. If the residual amount is >3μm, the acid concentration in the two acid tanks will be increased by 0.5% and 0.8% respectively, while the heating rate will be increased by 10% and the acid replacement frequency will be increased by 10%. 2) When the thickness of residual iron oxide scale detected is <1μm, Then reduce the acid concentration in acid tank No. 1 by 0.3~0.5% and reduce the acid replacement frequency by 5%.

[0013] Furthermore, the initial concentration L1 of hydrochloric acid in acid tank No. 1 is specifically 4~5%, the initial concentration L1 of hydrochloric acid in acid tank No. 2 is specifically 5~8%, and the temperature T of the two acid tanks is specifically 80~90℃.

[0014] Furthermore, the rough rolling descaling process specifically involves adding one pass of rough rolling with a preset reduction amount before normal finishing rolling. The reduction rate of this pass is controlled at 10-15%. At the same time, rough rolling is performed using rough surface work rolls with a surface roughness Ra range of 2-4 μm.

[0015] Furthermore, the precision rolling forming process specifically involves using a smooth work roll with a surface roughness Ra≤0.8μm to perform a preset number of precision rolling passes, with the reduction rate of each pass gradually decreasing until the silicon steel strip is rolled to the target thickness.

[0016] Compared with the prior art, the present invention has the following main advantages: 1. This invention uses low-concentration hydrochloric acid instead of traditional high-concentration hydrochloric acid, and combines high-temperature pickling to enhance reaction activity. While ensuring the removal effect of iron oxide scale, it can significantly reduce hydrochloric acid consumption. At the same time, the low-concentration hydrochloric acid reduces the corrosiveness of the equipment, which can save equipment maintenance costs.

[0017] 2. This invention employs a two-stage gradient concentration pickling process combined with a high-temperature process to achieve efficient layer-by-layer removal of iron oxide scale. Furthermore, by adaptively adjusting the pickling parameters, the process can be optimized in real time according to the actual residual amount, significantly improving the pickling effect. Moreover, by adding a rough rolling descaling pass before the subsequent cold rolling process, residual iron oxide scale can be completely removed, avoiding its impact on the cold rolling quality.

[0018] 3. This invention adaptively adjusts pickling parameters based on the amount of residual iron oxide scale on the steel strip surface, which can effectively avoid fluctuations in pickling effect caused by differences in raw material iron oxide scale. Combined with the design of a collaborative cold rolling process, it can ensure the stability of the production process and the product qualification rate. Attached Figure Description

[0019] Figure 1 This is an overall flow chart of the pickling and cold rolling process in an embodiment of the present invention; Figure 2 This is a scanning electron microscope (SEM) image of the iron oxide scale on the hot-rolled coil in an embodiment of the present invention; Figure 3 This is a scanning electron microscope (SEM) image of iron oxide scale after high-temperature, low-acid-consumption pickling in an embodiment of the present invention; Figure 4 This is a scanning electron microscope (SEM) image of the cross-section of the steel plate after rough-surface roll rolling in an embodiment of the present invention. Figure 1 ; Figure 5 This is a scanning electron microscope (SEM) image of the cross-section of the steel plate after rough-surface roll rolling in an embodiment of the present invention. Figure 2 . Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention. Furthermore, the technical features involved in the various embodiments of this invention described below can be combined with each other as long as they do not conflict with each other.

[0021] It should be noted that, depending on the implementation needs, the various steps / components described in this application can be broken down into more steps / components, or two or more steps / components or parts of the operation of steps / components can be combined into new steps / components to achieve the purpose of this invention.

[0022] In this invention, unless otherwise expressly specified and limited, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise expressly and specifically limited.

[0023] Example 1: This example provides a high-temperature, low-acid-consumption pickling and cold-rolling process for silicon steel strip, such as... Figure 1 As shown, the main steps include the following: Step S1, Hot-rolled coil preparation Silicon steel strips after hot rolling were selected as raw materials, and their surface iron oxide scale was pretreated and tested.

[0024] like Figure 2As shown in this example, the thickness of the iron oxide scale on the surface of the hot-rolled silicon steel strip is 8-9 μm. The oxide layer is mainly composed of different iron oxides such as FeO, Fe2O3, and Fe3O4, and contains 0.5-3.0% Si element by mass. The Si element exists in the iron oxide scale in the form of SiO2 or iron-silicon composite oxide, which increases the stability of the iron oxide scale and the difficulty of removal.

[0025] Furthermore, the selected hot-rolled steel strip must be in a regular shape and free from severe side bending, tapering, or other defects to avoid affecting the continuity of subsequent pickling and cold rolling processes.

[0026] Step S2, two-stage high-temperature low-concentration pickling A two-section shallow-tank turbulent-flow hydrochloric acid pickling device is used for continuous pickling of hot-rolled silicon steel coils. The total length of the pickling tank in the pickling device is 35m, and the two sections of the pickling tank are arranged in series to ensure continuous passage of the steel strip. The specific process includes: S11, Acid Concentration Control: A gradient increase in acid concentration is adopted. The hydrochloric acid concentration in acid tank 1 (inlet side) is controlled at 4-5%, and the hydrochloric acid concentration in acid tank 2 (outlet side) is controlled at 5-8%. The gradient concentration design allows the steel belt to undergo a preliminary reaction in the low-concentration acid solution to dissolve the loose iron oxide scale on the surface, and then enter the slightly higher concentration acid solution to deeply remove the residual iron oxide scale. This ensures the removal effect while avoiding the waste of the overall high-concentration acid solution.

[0027] S12, Pickling Temperature Control: The acid temperature in both acid tanks is raised to 80-90℃. A stepped heating method is used, with the heating rate controlled at 3℃ / h to avoid damage caused by excessively rapid heating, which could lead to localized accelerated acid evaporation or uneven heating of the equipment. The high-temperature environment significantly accelerates the chemical reaction rate between hydrochloric acid and iron oxide scale, compensating for the insufficient reactivity of low-concentration acid solutions.

[0028] S13, Pickling Time and Speed ​​Control: The total pickling time for the steel strip in the two pickling tanks is 3.5 minutes, corresponding to a pickling speed control of 10 m / min. By precisely controlling the pickling speed, sufficient reaction time for the iron oxide scale is ensured, while maintaining production efficiency.

[0029] S14, Acid Quality Control: Increase the acid replacement frequency of the two acid tanks to ensure that the iron salt (mainly FeCl2) content in the acid is always controlled at <100g / L. Excessive iron salt content will reduce the activity of the acid and affect the pickling effect. Regularly test the iron salt content in the acid and replace the acid in a timely manner to ensure stable pickling efficiency.

[0030] After the above pickling process, the surface of the steel strip is inspected, such as... Figure 3As shown, the results indicate that most of the iron oxide scale on the steel plate surface has been removed through chemical reaction, leaving only a small amount of tightly adhered iron oxide scale. The thickness of the remaining iron oxide scale is about 2 μm, and it is evenly distributed without large-area aggregation.

[0031] Step S3, adaptive adjustment of pickling parameters An adaptive control system for pickling parameters was established to monitor the amount of residual iron oxide scale on the surface of the steel strip in real time after pickling. An online laser thickness gauge and a high-definition image acquisition system were used to detect the thickness and distribution of residual iron oxide scale at multiple detection points (five detection points evenly selected along the width of the steel strip, and one detection point every 10m along the length) of each roll of steel strip, and the detection data was transmitted to the control system in real time.

[0032] The control system adaptively adjusts the pickling parameters based on a preset residual iron oxide scale threshold (normal threshold is ≤2μm): when the residual iron oxide scale thickness is detected to be >2μm, if the residual amount is within the range of 2-3μm, the concentration of acid tank 1 is increased by 0.5%, the concentration of acid tank 2 is increased by 0.5%, while the heating rate remains unchanged, and the acid replacement frequency is appropriately increased; if the residual amount is >3μm, in addition to adjusting the acid concentration, the heating rate is increased to 3.3℃ / h, the pickling time is extended to 4.0s (achieved by reducing the pickling rate to 8.75m / min), and the acid replacement frequency is further increased until the residual iron oxide scale amount drops to within the threshold range; when the residual iron oxide scale thickness is detected to be <1μm, the concentration of acid tank 1 is appropriately reduced by 0.3-0.5%, the acid replacement frequency is reduced, and acid consumption is further reduced while ensuring the removal effect.

[0033] Step S4, Collaborative cold rolling process After being pickled at high temperature and low concentration, the silicon steel coils enter the cold rolling process. To address the characteristic of a small amount of residual iron oxide scale on the surface after pickling, a two-stage cold rolling process of rough rolling for descaling and finish rolling for forming is adopted. 1) Rough Rolling Descaling Process: A rough rolling pass with a small reduction is added before normal finishing rolling to loosen and remove residual iron oxide scale from the surface. The reduction rate of this pass is controlled at 10-15%. If the reduction rate is too low, the iron oxide scale will not be effectively loosened; if the reduction rate is too high, it may lead to uneven deformation of the steel strip. At the same time, work rolls with a large surface roughness are used for rolling. After the work rolls are treated with a special grinding process, the surface roughness Ra of the rolls is in the range of 2-4μm. The rough roll surface can enhance the friction and shear force on the residual iron oxide scale on the steel strip surface, effectively peeling it off and removing it. Moreover, the peeled iron oxide scale fragments will be embedded in the pits on the roll surface, preventing them from adhering to the roll surface or scratching the steel strip surface.

[0034] like Figure 4As shown, after this rolling pass, the residual iron oxide scale on the surface of the steel strip has been completely removed, leaving grinding grooves of varying depths formed by the roughness of the work rolls on the plate surface, with a groove depth of about 10-15μm.

[0035] 2) Finishing Rolling Process: After roughing, multi-pass normal cold rolling is performed using smooth work rolls. The surface roughness value of the smooth work rolls is Ra≤0.8μm. Based on the final product thickness requirements, the finishing rolling passes and reduction rates for each pass are rationally set, with the total reduction rate controlled at 60-80%. By gradually reducing the reduction rate, the steel strip gradually reaches the target thickness. Simultaneously, the smooth work rolls smooth out the grooves on the strip surface, improving surface finish. After final cold rolling, the surface finish of the steel strip is Ra≤0.8μm, meeting the surface requirements for high-quality silicon steel strip.

[0036] Example 2: This example provides a high-temperature, low-acid-consumption pickling and cold rolling process for silicon steel strip, the main steps of which are as follows; Step S1: Hot-rolled coil preparation: Select silicon steel hot-rolled coils with a surface iron oxide scale thickness of 8-9 μm, wherein the iron oxide scale contains FeO, Fe2O3, Fe3O4 and Si elements; Step S2: Two-stage high-temperature low-concentration pickling, using a two-stage shallow tank turbulent hydrochloric acid pickling device, with a concentration of 4-5% in tank 1 and 5-8% in tank 2, an acid temperature of 80-90℃, a heating rate of 3℃ / h, a pickling time of 3.5s, a pickling speed of 10m / min, and controlling the iron salt content in the acid solution to be <100g / L; Step S3: Adaptive control of pickling parameters, detecting the amount of residual iron oxide scale after pickling, and adaptively adjusting the acid tank concentration, heating rate and acid replacement frequency; Step S4: Cooperative cold rolling process, first rough rolling to remove scale, then fine rolling to form with smooth rolls.

[0037] Furthermore, in step S2, the two acid tanks of the two-section shallow-tank turbulent hydrochloric acid pickling device are arranged in series.

[0038] Furthermore, in step S3, an online laser thickness measuring instrument and a high-definition image acquisition system are used to detect the amount of residual iron oxide scale, and multiple detection points are uniformly selected along the width and length directions of the steel strip.

[0039] Furthermore, in step S3, when the residual iron oxide scale thickness is >2μm and ≤3μm, the concentration of acid tanks No. 1 and No. 2 is increased by 0.5% to increase the acid replacement frequency; when the residual iron oxide scale thickness is >3μm, the acid tank concentration is increased by 0.5%, the heating rate is increased to 3.5℃ / h, and the pickling time is extended to 4.0s.

[0040] Furthermore, in step S4, the reduction rate of the rough rolling descaling process is 10-15%, and the surface roughness of the work roll Ra = 2-4 μm; the finishing rolling process uses smooth work rolls with a surface roughness Ra ≤ 0.8 μm and a total reduction rate of 60-80%.

[0041] Example 3: Based on the same inventive concept, this example also provides a pickling and cold rolling equipment for silicon steel strip, which adopts the pickling and cold rolling process described above.

[0042] Furthermore, all parts of this application that are not described in detail are the same as or implemented using existing technology.

[0043] In summary: 1. This invention uses low-concentration hydrochloric acid instead of traditional high-concentration hydrochloric acid, and combines high-temperature pickling to enhance reaction activity. While ensuring the removal effect of iron oxide scale, it can significantly reduce hydrochloric acid consumption. At the same time, the low-concentration hydrochloric acid reduces the corrosiveness of the equipment, which can save equipment maintenance costs.

[0044] 2. This invention employs a two-stage gradient concentration pickling process combined with a high-temperature process to achieve efficient layer-by-layer removal of iron oxide scale. Furthermore, by adaptively adjusting the pickling parameters, the process can be optimized in real time according to the actual residual amount, significantly improving the pickling effect. Moreover, by adding a rough rolling descaling pass before the subsequent cold rolling process, residual iron oxide scale can be completely removed, avoiding its impact on the cold rolling quality.

[0045] 3. This invention adaptively adjusts pickling parameters based on the amount of residual iron oxide scale on the steel strip surface, which can effectively avoid fluctuations in pickling effect caused by differences in raw material iron oxide scale. Combined with the design of a collaborative cold rolling process, it can ensure the stability of the production process and the product qualification rate.

[0046] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product embodied on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0047] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart... Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0048] Those skilled in the art will readily understand that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A high-temperature, low-acid-consumption pickling and cold-rolling process for silicon steel strip, characterized in that, Includes the following steps: S1, Hot-rolled coil preparation: Select the hot-rolled silicon steel strip as raw material and test the thickness of the iron oxide scale and the composition of the oxide layer on its surface; S2, Two-stage high-temperature low-concentration pickling: A two-stage shallow tank turbulent hydrochloric acid pickling device is used to perform gradient high-temperature low-concentration continuous pickling on silicon steel strip raw materials. The two acid tanks in the pickling device are arranged in series. S3, Adaptive adjustment of pickling parameters: Real-time detection of the amount of residual iron oxide scale on the surface of silicon steel strip after pickling, combined with the preset residual iron oxide scale threshold, adaptive adjustment of the pickling parameters of the hydrochloric acid pickling device. S4, Collaborative Cold Rolling Process: A rough rolling descaling process is used to completely remove the residual iron oxide scale on the surface of the silicon steel strip, and then a precision rolling forming process is used to cold roll the silicon steel strip to the target thickness.

2. The high-temperature, low-acid-consumption pickling and cold rolling process for silicon steel strip according to claim 1, characterized in that, The gradient high-temperature low-concentration continuous pickling specifically includes: S11, Acid concentration control: The two acid tanks adopt a gradient increase in acid concentration. The initial concentration of hydrochloric acid in acid tank 1 is controlled at L1, and the initial concentration of hydrochloric acid in acid tank 2 is controlled at L2, and L1 < L2. S12, pickling temperature control: Based on the preset initial heating rate V0 and preset time interval t1, the acid temperature of the two acid tanks is increased to temperature T in a stepped heating manner. S13, Pickling time and speed control: Based on the acid concentration and pickling temperature in the two acid tanks, and combined with the iron oxide scale thickness h detected in step S1, determine the total pickling time and corresponding pickling speed of the two acid tanks. S14, Acid Replacement Frequency Control: Replace the acid in the two acid tanks according to the preset initial acid replacement frequency W0.

3. The high-temperature, low-acid-consumption pickling and cold rolling process for silicon steel strip according to claim 2, characterized in that, The total pickling time t of the two acid tanks is calculated as follows: In the formula, K is the reaction correction coefficient, and C1 and C2 are the reaction weight coefficients of acid tank No. 1 and acid tank No. 2, respectively.

4. The high-temperature, low-acid-consumption pickling and cold rolling process for silicon steel strip according to claim 3, characterized in that, The pickling rate v is calculated as follows: In the formula, D is the total length of the two acid tanks.

5. The high-temperature, low-acid-consumption pickling and cold rolling process for silicon steel strip according to claim 2, characterized in that, The initial acid replacement frequency W0 is calculated and determined based on the increase in iron salt content of the acid solution in the two acid tanks within a preset time interval t2.

6. The high-temperature, low-acid-consumption pickling and cold rolling process for silicon steel strip according to claim 2, characterized in that, The adaptive adjustment of the pickling parameters specifically includes: 1) When the thickness of residual iron oxide scale detected is >2μm, If the residual amount is in the range of 2-3μm, the acid concentration in the two acid tanks will be increased by 0.5% respectively, while keeping the heating rate unchanged and increasing the acid replacement frequency by 5%. If the residual amount is >3μm, the acid concentration in the two acid tanks will be increased by 0.5% and 0.8% respectively, while the heating rate will be increased by 10% and the acid replacement frequency will be increased by 10%. 2) When the thickness of residual iron oxide scale detected is <1μm, Then reduce the acid concentration in acid tank No. 1 by 0.3~0.5% and reduce the acid replacement frequency by 5%.

7. The high-temperature, low-acid-consumption pickling and cold rolling process for silicon steel strip according to claim 2, characterized in that, The initial concentration L1 of hydrochloric acid in acid tank No. 1 is specifically 4~5%, the initial concentration L1 of hydrochloric acid in acid tank No. 2 is specifically 5~8%, and the temperature T of the two acid tanks is specifically 80~90℃.

8. The high-temperature, low-acid-consumption pickling and cold rolling process for silicon steel strip according to claim 1, characterized in that, The roughing and descaling process specifically involves adding one pass of roughing with a preset reduction amount before normal finishing rolling. The reduction rate of this pass is controlled at 10-15%. At the same time, roughing rolling is performed using rough work rolls with a surface roughness Ra range of 2-4 μm.

9. The high-temperature, low-acid-consumption pickling and cold rolling process for silicon steel strip according to claim 8, characterized in that, The precision rolling forming process specifically involves using a smooth work roll with a surface roughness Ra≤0.8μm to perform a preset number of precision rolling passes, with the reduction rate of each pass gradually decreasing until the silicon steel strip is rolled to the target thickness.

10. A pickling and cold rolling equipment for silicon steel strip, characterized in that, The pickling and cold rolling process described in any one of claims 1 to 9 is employed.

Images