A stainless steel annealing pickling method and system for hot rolled coils or cold rolled coils

Abstract

This invention belongs to the field of stainless steel coil annealing and pickling technology, specifically a method and system for stainless steel annealing and pickling of hot-rolled or cold-rolled coils. The method includes the following steps: S1, obtaining the steel coil to be annealed and pickled; S2, if the steel coil is a hot-rolled coil, proceed to step S21, and if the steel coil is a cold-rolled coil, proceed to step S22; S21, the hot-rolled coil is sequentially uncoiled, subjected to first annealing, first cooling, descaling, shot blasting, first electrolysis, pickling, and coiling; S22, the cold-rolled coil is sequentially uncoiled, subjected to second annealing, second cooling, descaling, shot blasting, second electrolysis, pickling, online leveling and tension straightening, and coiling. Through hardware compatibility modifications and matching process parameters, a single hot annealing and pickling unit can directly process cold-rolled thin strip steel. Even with insufficient hot-rolled coil production, it maximizes the use of existing equipment, resulting in high equipment versatility and a high pass rate for the sheet quality of the modified cold-rolled coils.

Description

Technical Field

[0001] This invention belongs to the field of stainless steel coil annealing and pickling technology, specifically a method and system for stainless steel annealing and pickling of hot-rolled or cold-rolled coils. Background Technology

[0002] Currently, most stainless steel continuous annealing and pickling production lines are designed as single annealing and pickling lines, meaning that hot-rolled annealing and pickling units and cold-rolled annealing and pickling units are usually set up independently. For hot-rolled stainless steel coils, the production process generally only requires annealing, water cooling, descaling, shot blasting, and pickling to meet the NO.1 surface quality requirements (referring to the surface condition of hot-rolled stainless steel coils after annealing, pickling, and removal of surface oxide scale). The cooling section of the annealing furnace is usually entirely water-cooled, and a clamp-type coiler is used at the exit for coiling. However, with changes in market demand and fluctuations in production tasks, companies often face situations where the output of hot-rolled black-skinned coils is not saturated. In order to maximize the use of existing equipment, the industry has tried to use existing hot-rolled annealing and pickling units for pickling and annealing treatment of cold-rolled coils. However, the surface grade requirements for cold-rolled strip steel are different from those for hot-rolled coils (it needs to reach 2B surface), which places extremely high demands on the surface quality and strip shape control of the unit. Directly utilizing existing hot-rolled annealing and pickling lines to produce cold-rolled coils has the following significant drawbacks: Incompatible cooling methods: Existing hot-rolled annealing and pickling lines only have water cooling in the annealing furnace cooling section, which cannot meet the cooling process requirements of cold-rolled stainless steel thin strips, hindering the shape control of cold-rolled coils; Lack of surface and shape straightening processes: Producing cold-rolled annealed and pickled coils requires additional leveling and straightening processes to meet the 2B surface quality requirements (referring to stainless steel coils in a cold-rolled state undergoing a light leveling roll after annealing and pickling to achieve appropriate brightness and flatness), but traditional hot-rolled pickling lines lack corresponding online leveling and straightening equipment. If offline leveling and straightening equipment is chosen, it will not only occupy a large amount of workshop space, but also have extremely high equipment investment and operating costs. The coiling equipment is prone to damaging the strip: the jaw-type coils used in hot annealing and pickling units are suitable for thick materials, but for thinner cold-rolled coils, especially those less than 0.6mm thick, the jaws cannot effectively clamp them, and the screw holes and elliptical structures on the coil surface easily lead to surface quality defects and sheet shape problems such as coil collapse and deformation in the strip. New unit construction is costly: investing in a dedicated cold annealing and pickling unit for cold-rolled coil production would result in extremely high investment costs, which does not meet the company's development needs for cost reduction and efficiency improvement. Therefore, there is an urgent need for a stainless steel annealing and pickling method and system that can be compatible with hot-rolled coil processing and meet the high-standard surface and sheet shape requirements of cold-rolled thin strips, in order to improve equipment versatility and achieve saturated production of the annealing and pickling line while controlling modification costs. Summary of the Invention

[0003] To address the aforementioned technical problems, this invention provides a method for annealing and pickling stainless steel for hot-rolled or cold-rolled coils, comprising the following steps: S1. Obtain the steel coil to be annealed and pickled; S2. If the steel coil is a hot-rolled coil, proceed to step S21; if the steel coil is a cold-rolled coil, proceed to step S22. S21. The hot-rolled coil is sequentially uncoiled, subjected to first annealing, first cooling, descaling, shot blasting, first electrolysis, pickling, and coiling, and the tension is controlled by a first tension control parameter, wherein the first cooling is a full water cooling mode. S22. The cold-rolled coil is subjected to uncoiling, second annealing, second cooling, descaling, shot blasting, second electrolysis, pickling, online leveling and stretching straightening, and coiling in sequence, and the tension is controlled by the second tension control parameter, wherein the second cooling is a mode of first air cooling and then water cooling.

[0004] In step S21, the temperature of the first annealing is 1050~1100℃, and the hot-rolled coil is water-cooled until its temperature is less than or equal to 70℃. In step S22, the temperature of the second annealing is 980~1020℃, and the second cooling includes first air cooling the cold-rolled coil until the temperature of the cold-rolled coil is less than or equal to 600℃, and then water cooling it until its temperature is less than or equal to 70℃.

[0005] Multiple tension sections are sequentially arranged along the direction of the strip's travel; In step S21, the steps for obtaining and controlling the first tension control parameter specifically include: obtaining the width and thickness of the hot-rolled coil, wherein the plurality of tension segments are nine tension segments sequentially corresponding to the strip's travel direction, according to the formula... Determine the tension of each corresponding tension segment, where F z For tension, F n Let F1 be the tension coefficient of the nth tension segment, where n is 1~9, a is the width, b is the thickness, and F1 is 1.0 dN / mm. 2 F2 is 0.7 dN / mm 2 F3 is 0.8 dN / mm 2 F4 is 6.0 dN / mm 2 F5 is 1.7 dN / mm 2 F6 has a strength of 0.8 dN / mm. 2 F7 has a strength of 2.0 dN / mm. 2 F8 is 1.5 dN / mm 2 F9 is 1.5 dN / mm 2 .

[0006] In step S22, the second tension control parameter specifically includes: when the width of the cold-rolled coil is 1230~1300mm, the tension of nine tension segments corresponding to the strip's travel direction is set according to the strip thickness, wherein the tensions of the first to ninth tension segments are denoted as T1 to T9; when the strip thickness is greater than or equal to 0.1mm and less than or equal to 0.3mm: the ranges of T1 to T9 are 2.0~6.0kN, 4.0~13.5kN, 1.2~4.5kN, 5.0~15.0kN, 5.0~16.0kN, 6.0~19.0kN, 15.0~45.0kN, 13.5~40.5kN, and 5.0~15.0kN respectively; when the strip thickness is greater than 0.3mm and less than or equal to 0.9mm: T1 to T The setting ranges for 9 are 8.0~18.0kN, 15.0~31.0kN, 5.5~12.5kN, 15.0~30.0kN, 16.0~31.5kN, 40.0~54.0kN, 57.5~112.5kN, 51.5~101.5kN, and 17.0~36.0kN, respectively. When the strip thickness is greater than 0.9mm and less than... When the thickness is 2.0mm, the setting ranges of T1 to T9 are 16.0~26.5kN, 28.0~44.0kN, 13.5~26.5kN, 26.0~40.5kN, 28.5~43.0kN, 30.0~55.0kN, 103.5~138.0kN, 95.0~128.5kN, and 37.5~52.5kN, respectively.

[0007] In step S22, the online leveling includes: the roller crown of the leveling machine is 0.18~0.20, the bending roller force is 15~25 tons, and the elongation is 0.10%~0.13%.

[0008] In step S22, the stretching and straightening includes: a stretching elongation of 0.14% to 0.16%, an overlap of 6 to 10 mm for the first bending roller, an overlap of 6 to 10 mm for the second bending roller, an overlap of 6 mm for the first lower straightening roller, and an overlap of 6 mm for the second upper straightening roller.

[0009] In step S21, the winding method is to use a jaw winding method, and no sleeve is used on the inner ring of the steel coil. In step S22, the winding method is divided into two types according to the thickness of the strip: when the thickness is greater than or equal to 0.6 mm and less than or equal to 2.0 mm, a clamp winding method is used and no sleeve is used; when the thickness is greater than or equal to 0.3 mm and less than 0.6 mm, a belt winding aid is added for winding, and a sleeve is added to the inner circle of the steel coil to prevent collapse.

[0010] To address the aforementioned technical problems, the present invention also provides a stainless steel annealing and pickling system for hot-rolled or cold-rolled coils, used to perform the above-described method, comprising, in sequence along the strip's travel direction: An uncoiling device for uncoiling the hot-rolled coil or the cold-rolled coil; Annealing furnace, used to anneal strip steel after it has been uncoiled; A cooling device that integrates switchable water-cooling and air-cooling components; Descaling equipment, including a scale-breaking machine and a shot blasting machine arranged in sequence; Pickling equipment, comprising an electrolytic cell and a pickling tank arranged in sequence; An online leveling and straightening device is installed after the pickling device and is used to perform surface treatment and shape correction on the cold-rolled coil; A winding device for winding processed strip steel, the winding device including a jaw-type winding drum and a belt winding aid disposed around the drum; Multiple tension rollers are distributed among the various pieces of equipment.

[0011] The cooling equipment is divided into seven cooling sections along the direction of the strip's travel; the first to fourth cooling sections are equipped with both air-cooling and water-cooling components to enable switching between air-cooling and water-cooling; the fifth to seventh cooling sections are equipped with the water-cooling components.

[0012] The plurality of tension rollers include, in sequence, a first tension roller to an eighth tension roller along the strip travel direction, and the first tension roller to the sixth tension roller are distributed between the uncoiling equipment and the pickling equipment. The pickling equipment is followed by a sixth tension roller and the winding equipment in sequence; the online leveling and straightening equipment is located between the sixth tension roller and the winding equipment, and the online leveling and straightening equipment includes, in sequence along the strip traveling direction: a seventh tension roller, a leveling machine, a stretching straightening machine and an eighth tension roller.

[0013] The equipment also includes: a narrow lap welding machine, which is located after the uncoiling equipment; the winding equipment also includes a sleeve, which is configured to be fitted onto the inner ring of the jaw-type winding drum when processing the cold-rolled coil with a thickness of 0.3~0.5mm.

[0014] This invention transforms the existing annealing furnace cooling section into a dual-mode system capable of switching between air cooling and water cooling. Different cooling standards are established for hot-rolled and cold-rolled coils to address the process differences, meeting the cooling requirements of cold-rolled thin strip steel and effectively improving the sheet quality of the cold-rolled coils. The original coiler is moved to the rear, and a leveling machine and a tension straightener are added at the end of the production line. This structure enables the produced cold-rolled coils to meet the 2B surface quality requirements without the need for offline leveling and tension straightening equipment, significantly reducing equipment investment costs. Through hardware compatibility modifications and corresponding process parameters, a single hot annealing and pickling unit can directly process cold-rolled thin strip steel. Even with insufficient hot-rolled coil production, existing equipment is utilized to the maximum extent, resulting in high equipment versatility. Furthermore, the sheet quality qualification rate of the modified cold-rolled coils is greater than or equal to 95%. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0016] Figure 1 This is a schematic diagram of the structure of a stainless steel annealing and pickling system for hot-rolled or cold-rolled coils in an embodiment of the present invention.

[0017] The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0018] The technical solutions described below in conjunction with the embodiments will be clearly and completely described. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0019] This invention provides a method for annealing and pickling stainless steel for hot-rolled or cold-rolled coils, comprising the following steps: S1. Obtain the steel coil to be annealed and pickled; In this embodiment, the steel coils to be processed include hot-rolled black strip coils and cold-rolled coils; wherein, the thickness range of hot-annealed and pickled stainless steel coils (i.e., hot-rolled coils) is typically 2.0~6.0mm, while the thickness range of cold-rolled stainless steel thin strips (i.e., cold-rolled coils) is typically 0.3~2.0mm; the purpose of this invention is to achieve high-quality processing of the above two types of steel coils with large thickness ranges and different surface requirements on the same annealing and pickling line through compatibility modifications to production line equipment and targeted design of process parameters.

[0020] S2. If the steel coil is a hot-rolled coil, proceed to step S21; if the steel coil is a cold-rolled coil, proceed to step S22. The reason for classifying and implementing this invention is that there are significant differences in TV value and annealing temperature between hot-rolled coils and cold-rolled coils, and the final surface quality grades they need to achieve are different. Specifically, hot-rolled coils are mainly used to meet the quality requirements of NO.1 surface after processing; while cold-rolled coils have higher surface grade requirements and need to meet the quality requirements of 2B surface. Therefore, the two have different process requirements for the cooling mode of the annealing furnace, the tension control model of the entire line, and whether surface flattening and straightening are required.

[0021] S21. The hot-rolled coil is sequentially uncoiled, subjected to first annealing, first cooling, descaling, shot blasting, first electrolysis, pickling, and coiling, and the tension is controlled by a first tension control parameter, wherein the first cooling is a full water cooling mode. Step S21 is mainly applicable to conventional hot annealing and pickling production. Due to the large thickness of hot-rolled coils and the relatively basic surface requirements, only annealing, cooling, descaling, shot blasting, and pickling processes are needed to meet the NO.1 surface requirements. In the first cooling stage after annealing, the original full water cooling mode can be directly used to meet the cooling requirements of hot-rolled coils. The first tension control parameter can be automatically calculated and dynamically adjusted by the secondary system according to the specific specifications of the strip and the preset tension coefficient to ensure stable transmission of thicker strips.

[0022] S22. The cold-rolled coil is subjected to uncoiling, second annealing, second cooling, descaling, shot blasting, second electrolysis, pickling, online leveling and stretching straightening, and coiling in sequence, and the tension is controlled by the second tension control parameter, wherein the second cooling is a mode of first air cooling and then water cooling.

[0023] Step S22 is the core improved process of this invention. For cold-rolled thin strip steel, the original water-cooled section of the annealing furnace no longer meets the production requirements. Therefore, the second cooling adopts the modified air-cooling followed by water-cooling mode, which is more conducive to the precise control of the shape of thin stainless steel sheets. At the same time, in order to achieve a 2B surface finish in cold-annealed pickled coils, a leveling and stretching straightening process must be added online after the pickling process to eliminate microscopic defects on the surface of the strip steel and correct the macroscopic shape. In addition, since the surface and properties of cold-annealed pickled coils are different from those of hot-rolled coils, a specially formulated second tension control parameter must be used for tension control to prevent strip breakage or surface scratches during high-speed operation and stretching straightening of thin materials.

[0024] Please see Figure 1 , Figure 1 This is a schematic diagram of the structure of a stainless steel annealing and pickling system for hot-rolled or cold-rolled coils in an embodiment of the present invention. The system consists of the following sections along the strip travel direction: inlet uncoiler, tension roll #1, inlet looper, tension roll #2, annealing furnace, tension roll #3, scale remover, tension roll #4, electrolytic pickling section, tension roll #5, outlet looper, tension roll #6, leveler, tension roll #7, tension leveler, tension roll #8, and outlet coiler. Each pair of tension rolls forms a tension section. The inlet uncoiler and tension roll #1 form a tension section, and tension roll #8 and outlet coiler form a tension section, for a total of 9 tension sections.

[0025] In all embodiments of the present invention, the following methods are used: Figure 1 The system shown processes hot-rolled or cold-rolled coils. In this embodiment of the invention, the steel used is 201 steel.

[0026] Example 1 The steel coil to be processed was a cold-rolled coil with a thickness of 0.48 mm and a width of 1250 mm. The stainless steel annealing and pickling method provided in this invention was used for processing. The specific steps and parameters are as follows: The tension is controlled using the second tension control parameter; since the thickness of the cold-rolled strip is 0.48mm, the tensions of T1 to T9 along the strip's travel direction are as follows: 12kN, 22kN, 9kN, 23kN, 20kN, 47kN, 85kN, 77kN, and 26kN. The second annealing is carried out in the annealing furnace at a temperature of 1000℃. The annealing furnace has seven cooling sections. The first to fourth cooling sections use air cooling until the strip temperature reaches 600℃. The fifth to seventh cooling sections use water cooling until the strip temperature reaches 70℃. After pickling, online leveling and stretch straightening are performed. The parameters of the leveling machine are: rolling force 250 tons, roll crown 0.20, bending roll force 15 tons, leveling tension 4.2 tons, and leveling elongation 0.10%. The parameters of the stretch straightening machine are: stretching tension 5.4 tons, stretching elongation 0.14%, overlap of the first and second bending rolls is 10 mm, and overlap of the first lower straightening roll and the second upper straightening roll is 6 mm. Since the steel strip thickness is 0.48mm, which is less than 0.6mm, a belt winding aid is used for winding, and a sleeve is added to the inner ring of the steel coil; after it comes off the production line, two plastic steel strappings are used to pack it in the middle.

[0027] Test results: The surface quality of the cold-rolled stainless steel strip treated in Example 1 meets the 2B surface standard, the strip is flat and free of macro and micro defects, the unit operates smoothly, and the finished product qualification rate reaches 98.5%.

[0028] Example 2 The steel coil to be processed is a hot-rolled coil with a thickness of 3.0 mm and a width of 1250 mm. The method of this invention is used for processing, and the specific steps and parameters are as follows: Tension is controlled using the first tension control parameter; based on the strip thickness and width, the strip cross-sectional area is 1250mm × 3.0mm = 3750mm². 2 According to the formula The tension coefficients of the nine tension segments are 1.0 dN / mm. 2 0.7dN / mm 2 0.8dN / mm 2 6.0 dN / mm 2 1.7dN / mm 2 0.8dN / mm 2 2.0dN / mm 2 1.5dN / mm 2 1.5dN / mm 2 The calculated tensions for each segment are 3750dN, 2625dN, 3000dN, 22500dN, 6375dN, 3000dN, 7500dN, 5625dN, and 5625dN, respectively.

[0029] The first annealing is carried out in the annealing furnace at a temperature of 1080℃. The first cooling control of the annealing furnace uses water cooling mode for all seven cooling sections until the temperature of the strip steel reaches 60℃.

[0030] After passing through annealing, cooling, descaling, shot blasting, and pickling, the strip steel is directly wound up using a clamp-type coil without using a sleeve; after coming off the production line, it is bundled in the middle with two carbon steel straps.

[0031] Test results: After annealing and pickling, the surface quality of the hot-rolled coils met the NO.1 surface requirements. The equipment had a high versatility, stable tension and operating conditions, and a finished product qualification rate of 99.2%.

[0032] Comparative Example 1 The difference from Example 1 is that the cooling section of the annealing furnace adopts the existing full water cooling mode (i.e., the first to seventh cooling sections are all water-cooled).

[0033] Test results: Because cold-rolled thin strip steel is extremely sensitive to temperature changes, full water cooling caused the strip steel to cool down too quickly and the thermal stress to be released unevenly. The strip steel showed obvious edge waviness and warping. Subsequent leveling and tensioning processes could not completely eliminate this plate defect, and the plate quality qualification rate dropped significantly to only 65.5%.

[0034] Comparative Example 2 The difference from Example 1 is that online leveling and stretching are not performed; the winding is performed directly.

[0035] Test results: The surface roughness of the strip steel is substandard and lacks luster, failing to meet the quality requirements of the 2B surface of cold-rolled coil; at the same time, the micro-unevenness of the strip steel cannot be effectively eliminated, and the overall pass rate of surface and plate shape is only 42.0%.

[0036] Comparative Example 3 The difference from Example 1 is that a conventional jaw-type spool is used for winding, and no sleeve is added to the inner ring.

[0037] Test results: Due to the strip thickness of only 0.48mm, the jaws could not effectively clamp the strip head. During the winding process, the screw holes and elliptical structure on the surface of the roll caused severe indentations and surface damage to several layers of the inner ring of the strip. After the steel coil was unloaded from the line, due to insufficient internal support, obvious coil collapse occurred, resulting in an extremely high scrap rate and a product qualification rate of only 15.0%.

[0038] Comparative Example 4 The difference from Example 1 is that the overlap of the first bending roller and the second bending roller of the stretching straightener is set to 15mm, and the overlap of the first lower straightening roller and the second upper straightening roller is set to 10mm.

[0039] Test results: Excessive overlap caused the thin strip steel to bend and deform excessively in the tension leveler, resulting in minor surface damage and creases, excessive elongation, and a product qualification rate of 58.5%.

[0040] Comparative Example 5 The difference from Example 1 is that the forces of the leveling machine and the tension leveling machine are reduced, so that the leveling elongation is 0.05% and the tension leveling elongation is 0.08%.

[0041] Test results: The strip failed to produce sufficient plastic elongation deformation, and there were still obvious edge wavy and local wave defects after exiting the line. The plate shape correction failed, and the product qualification rate was 72.0%.

[0042] Comparative Example 6 The difference from Example 1 is that the tension is controlled by the first tension control parameter instead of the second tension control parameter.

[0043] Test results: The tension coefficient set for hot-rolled thick plates is too large for thin cold-rolled coils with a specification of 0.48mm. The actual tension applied by the system far exceeds the yield strength of the thin strip steel, causing the strip steel to undergo severe plastic elongation deformation in the annealing furnace and break directly, making continuous production impossible.

[0044] Comparative Example 7 The difference from Example 2 is that the temperature of the first annealing is 1000°C.

[0045] Test results: Due to the thick and dense iron oxide scale on the surface of the hot-rolled stainless steel black strip, the annealing temperature of 1000℃ was too low, resulting in insufficient phase transformation, cracking, and loosening of the internal structure of the oxide scale. In subsequent descaling and pickling processes, the oxide scale was extremely difficult to remove completely, leaving large areas of residual black spots on the strip surface. This failed to meet the quality requirements of the NO.1 surface, resulting in a product qualification rate of 55.0%.

[0046] Comparative Example 8 The difference from Example 1 is that the temperature of the second annealing is 1080°C.

[0047] Test results: Due to the thinness of the cold-rolled thin strip and the cold work hardening process, the annealing temperature of 1080℃ was too high, resulting in excessive grain growth inside the strip. Although the surface was clean after pickling, an obvious "orange peel" phenomenon appeared on the surface of the strip during the subsequent leveling and stretching straightening process. The yield strength of the material was also severely reduced, which seriously affected the surface quality of 2B and the mechanical properties of the product. The product qualification rate was 48.5%.

[0048] Comparative Example 9 The difference from Example 1 is that during the second cooling, the cold-rolled coil is first air-cooled until the strip temperature drops to 750°C, and then water cooling is introduced in advance until its temperature is less than or equal to 70°C.

[0049] Test results: Due to the high temperature at the end of the air cooling process, the strip was quickly switched to full water cooling. At this time, the temperature gradient and thermal stress inside the thin strip were still large. The rapid cooling and contraction caused uneven stress release in the strip, resulting in slight wavy bending deformation. This increased the straightening load on the subsequent tension leveler. The product qualification rate was 82.0%.

[0050] This invention transforms the existing annealing furnace cooling section into a dual-mode system capable of switching between air cooling and water cooling. Different cooling standards are established for hot-rolled and cold-rolled coils to address the process differences, meeting the cooling requirements of cold-rolled thin strip steel and effectively improving the sheet quality of the cold-rolled coils. The original coiler is moved to the rear, and a leveling machine and a tension straightener are added at the end of the production line. This structure enables the produced cold-rolled coils to meet the 2B surface quality requirements without the need for offline leveling and tension straightening equipment, significantly reducing equipment investment costs. Through hardware compatibility modifications and corresponding process parameters, a single hot annealing and pickling unit can directly process cold-rolled thin strip steel. Even with insufficient hot-rolled coil production, existing equipment is utilized to the maximum extent, resulting in high equipment versatility. Furthermore, the sheet quality qualification rate of the modified cold-rolled coils is greater than or equal to 95%.

[0051] The above description is merely a preferred embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural transformations made using the contents of the present invention under the inventive concept of the present invention, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present invention.

Claims

1. A stainless steel annealing pickling method for a hot-rolled coil or a cold-rolled coil, characterized by, Includes the following steps: S1. Obtain the steel coil to be annealed and pickled; S2. If the steel coil is a hot-rolled coil, proceed to step S21; if the steel coil is a cold-rolled coil, proceed to step S22. S21. The hot-rolled coil is sequentially uncoiled, subjected to first annealing, first cooling, descaling, shot blasting, first electrolysis, pickling, and coiling, and the tension is controlled by a first tension control parameter, wherein the first cooling is a full water cooling mode. S22. The cold-rolled coil is subjected to uncoiling, second annealing, second cooling, descaling, shot blasting, second electrolysis, pickling, online leveling and stretching straightening, and coiling in sequence, and the tension is controlled by the second tension control parameter, wherein the second cooling is a mode of first air cooling and then water cooling.

2. The annealing and pickling method for stainless steel used in hot-rolled or cold-rolled coils according to claim 1, characterized in that: In step S21, the temperature of the first annealing is 1050~1100℃, and the hot-rolled coil is water-cooled until its temperature is less than or equal to 70℃. In step S22, the temperature of the second annealing is 980~1020℃, and the second cooling includes first air cooling the cold-rolled coil until the temperature of the cold-rolled coil is less than or equal to 600℃, and then water cooling it until its temperature is less than or equal to 70℃.

3. A stainless steel annealing and pickling method for hot-rolled coils or cold-rolled coils according to claim 1, characterized in that, Multiple tension sections are sequentially arranged along the direction of the strip's travel; In step S21, the steps for obtaining and controlling the first tension control parameter specifically include: obtaining the width and thickness of the hot-rolled coil, wherein the plurality of tension segments are nine tension segments sequentially corresponding to the strip's travel direction, according to the formula... Determine the tension of each corresponding tension segment, where F z For tension, F n Let F1 be the tension coefficient of the nth tension segment, where n is 1~9, a is the width, b is the thickness, and F1 is 1.0 dN / mm. 2 F2 is 0.7 dN / mm 2 F3 is 0.8 dN / mm 2 F4 is 6.0 dN / mm 2 F5 is 1.7 dN / mm 2 F6 has a strength of 0.8 dN / mm. 2 F7 has a strength of 2.0 dN / mm. 2 F8 is 1.5dN / mm 2 F9 is 1.5 dN / mm 2 . In step S22, the second tension control parameter specifically includes: when the width of the cold-rolled coil is 1230~1300mm, the tension of nine tension segments corresponding to the strip's travel direction is set according to the strip thickness, wherein the tensions of the first to ninth tension segments are denoted as T1 to T9; when the strip thickness is greater than or equal to 0.1mm and less than or equal to 0.3mm: the ranges of T1 to T9 are 2.0~6.0kN, 4.0~13.5kN, 1.2~4.5kN, 5.0~15.0kN, 5.0~16.0kN, 6.0~19.0kN, 15.0~45.0kN, 13.5~40.5kN, and 5.0~15.0kN respectively; when the strip thickness is greater than 0.3mm and less than or equal to 0.9mm: T1 to T The setting ranges for 9 are 8.0~18.0kN, 15.0~31.0kN, 5.5~12.5kN, 15.0~30.0kN, 16.0~31.5kN, 40.0~54.0kN, 57.5~112.5kN, 51.5~101.5kN, and 17.0~36.0kN, respectively. When the strip thickness is greater than 0.9mm and less than... When the thickness is 2.0mm, the setting ranges of T1 to T9 are 16.0~26.5kN, 28.0~44.0kN, 13.5~26.5kN, 26.0~40.5kN, 28.5~43.0kN, 30.0~55.0kN, 103.5~138.0kN, 95.0~128.5kN, and 37.5~52.5kN, respectively.

4. The annealing and pickling method for stainless steel used in hot-rolled or cold-rolled coils according to claim 1, characterized in that, In step S22, the online leveling includes: the roller crown of the leveling machine is 0.18~0.20, the bending roller force is 15~25 tons, and the elongation is 0.10%~0.13%.

5. The annealing and pickling method for stainless steel used in hot-rolled or cold-rolled coils according to claim 1, characterized in that, In step S22, the stretching and straightening includes: a stretching elongation of 0.14% to 0.16%, an overlap of 6 to 10 mm for the first bending roller, an overlap of 6 to 10 mm for the second bending roller, an overlap of 6 mm for the first lower straightening roller, and an overlap of 6 mm for the second upper straightening roller.

6. The annealing and pickling method for stainless steel used in hot-rolled or cold-rolled coils according to claim 1, characterized in that, In step S21, the winding method is to use a jaw winding method, and no sleeve is used on the inner ring of the steel coil. In step S22, the winding method is divided into two types according to the thickness of the strip: when the thickness is greater than or equal to 0.6 mm and less than or equal to 2.0 mm, a clamp winding method is used and no sleeve is used; when the thickness is greater than or equal to 0.3 mm and less than 0.6 mm, a belt winding aid is added for winding, and a sleeve is added to the inner circle of the steel coil to prevent collapse.

7. A stainless steel annealing and pickling system for hot-rolled or cold-rolled coils, used to perform the method according to any one of claims 1 to 6, characterized in that, Along the direction of strip travel, the following are included in sequence: An uncoiling device for uncoiling the hot-rolled coil or the cold-rolled coil; Annealing furnace, used to anneal strip steel after it has been uncoiled; A cooling device that integrates switchable water-cooling and air-cooling components; Descaling equipment, including a scale-breaking machine and a shot blasting machine arranged in sequence; Pickling equipment, comprising an electrolytic cell and a pickling tank arranged in sequence; An online leveling and straightening device is installed after the pickling device and is used to perform surface treatment and shape correction on the cold-rolled coil. A winding device for winding processed strip steel, the winding device including a jaw-type winding drum and a belt winding aid disposed around the drum; Multiple tension rollers are distributed among the various pieces of equipment.

8. A stainless steel annealing and pickling system for hot-rolled or cold-rolled coils according to claim 7, characterized in that, The cooling equipment is divided into seven cooling sections along the direction of the strip's travel; the first to fourth cooling sections are equipped with both the air-cooling component and the water-cooling component to enable switching between air cooling and water cooling; the fifth to seventh cooling sections are equipped with the water-cooling component.

9. A stainless steel annealing and pickling system for hot-rolled or cold-rolled coils according to claim 7, characterized in that, The plurality of tension rollers include, in sequence, a first tension roller to an eighth tension roller along the strip travel direction, and the first tension roller to the sixth tension roller are distributed sequentially between the uncoiling equipment and the pickling equipment. The pickling equipment is followed by a sixth tension roller and the winding equipment in sequence; the online leveling and straightening equipment is located between the sixth tension roller and the winding equipment, and the online leveling and straightening equipment includes, in sequence along the strip traveling direction: a seventh tension roller, a leveling machine, a stretching straightening machine and an eighth tension roller.

10. A stainless steel annealing and pickling system for hot-rolled or cold-rolled coils according to claim 7, characterized in that, Also includes: A narrow lap welding machine is provided after the uncoiling equipment; the winding equipment further includes a sleeve configured to be fitted onto the inner ring of the jaw-type winding drum when processing the cold-rolled coil with a thickness of 0.3~0.5mm.

Images