High flatness control method for high strength alloy ribbon foils

Abstract

A method for controlling the flatness of high-strength alloy strip and foil includes the following steps: 1) straightening the strip and foil blank for the first time, adjusting the transverse unevenness of the blank, rolling at least two times, annealing the blank after each rolling, and setting the tension for each rolling according to the blank parameters to obtain a first-straightened strip and foil blank that meets the requirements; 2) straightening the first-straightened strip and foil blank for the second time, adjusting the longitudinal unevenness of the blank, rolling at least two times, annealing the blank after each rolling, and setting the tension for each rolling according to the first-straightened strip and foil blank parameters to obtain a second-straightened strip and foil blank that meets the requirements; 3) straightening the second-straightened strip and foil blank for the third time, adjusting the overall unevenness of the blank, rolling at least two times, annealing the blank after each rolling, and setting the tension for each rolling according to the second-straightened strip and foil blank parameters to obtain a finished high-strength alloy strip and foil blank that meets the requirements.

Description

Technical Field

[0001] This invention relates to the field of alloy material forming and processing, and specifically to a leveling method for adjusting and controlling the high flatness of high-strength alloy strips and foils. Background Technology

[0002] High-strength alloy strips and foils (such as stainless steel, nickel-based alloys, and titanium alloys) are widely used in precision electronics, aerospace, new energy batteries, and medical devices. With the development of high-end manufacturing, the requirements for thickness accuracy and surface flatness of strips and foils are becoming increasingly stringent. For example, new energy photovoltaic solar cells and automotive batteries (such as stainless steel and copper foils) require a flatness of ≤1.0mm / twice the width and a thickness tolerance of ±0.005mm to ensure coating uniformity. Electronic communication strips (such as stainless steel foils) need to control flatness to ≤0.5mm / twice the width and a thickness tolerance of ±0.003mm to match micron-level assembly precision. Aerospace and other fields require strips (such as high-temperature alloys, stainless steel, and titanium alloy foils) with a flatness of ≤0.2mm / twice the width and a thickness tolerance of ±0.002mm to ensure sealing performance against high-temperature and corrosive fluids.

[0003] While traditional 20-roll precision rolling mills possess high rigidity and can roll strips with required thickness accuracy, they suffer from significant challenges with high-strength alloys (such as high-temperature alloys GH4169, GH4145, GH3230, and 3J21, precipitation-hardening stainless steel 0Cr17Ni7Al, and ultra-high-strength steel 7C27Mo2) due to their high deformation resistance (>1500MPa). These challenges include elastic deformation of the roll system during rolling, tension instability due to inlet / outlet tension gradients (e.g., tension difference >5%) or dynamic acceleration / deceleration, differences in grain orientation caused by the work hardening index and plastic anisotropy of high-strength alloys, and uneven lateral distribution of rolling force. These factors lead to uneven local plastic deformation and periodic undulations at the strip edges or center. Conventional straightening techniques struggle to apply effective plastic strain, resulting in poor flatness, insufficient stress release, uncoordinated tension systems, and residual warping due to high springback rates. Especially in the thickness range of 0.05~0.15mm, even slight changes in pressing force can significantly affect the final flatness, causing problems such as unstable plate shape and high processing repetition rate.

[0004] The invention patent CN101961740B, entitled "Stretching, Bending, and Straightening Equipment for Strip Material of Nickel-Metal Hydride Battery Anode Substrate," describes a device for stretching, bending, and straightening strip foil materials with a thickness not exceeding 0.035 mm under constant temperature conditions using bending rollers and straightening rollers. The resulting strip foil material has an unevenness of 0.5 mm / twice the width. However, this technology is designed for materials and strip dimensions that differ from those used for high-strength alloy strip foil materials. Furthermore, it does not optimize the bending and straightening process, resulting in a flatness control level greater than 0.1 mm / twice the width, which is insufficient to meet the flatness control requirements of high-strength alloy strip foil materials. The invention patent CN115255034B, entitled "A Method for Ultra-Flat Tension Tension Bending Straightening of Special Alloy Precision Foil with a Thickness of Less Than 0.05mm," employs a precision straightening machine and sets up two processes: initial straightening and product straightening. By controlling straightening process parameters such as straightening tension, elongation, and reduction, a precision alloy strip foil with an unevenness of 0.1mm / twice the width is obtained. However, the material type and strip size specifications of this technology are different from those of high-strength alloy strip foil. Furthermore, this patent focuses on adjusting the transverse unevenness of the strip and does not describe the adjustment of longitudinal unevenness or the control of incoming material dimensional accuracy and condition. Invention Patent 3: The invention patent CN119387316A, entitled "A Method for Controlling the Shape of Precipitation-Hardening Martensitic SUS630 Stainless Steel Cold-Rolled Strip," uses a three-roller straightening machine for bending and straightening. By controlling the tension of the straightening rollers, the pressing angle of the straightening rollers, and the elongation, SUS630 stainless steel strip foil with an unevenness ≤3mm / twice the width is obtained. However, the material type and strip size specifications of this technology are different from those of high-strength alloy strip foil. Moreover, this patent focuses on the shape quality control in the entire strip foil preparation process, with a flatness control level >0.1mm / twice the width, which is difficult to meet the flatness control requirements of high-strength alloy strip foil.

[0005] Therefore, obtaining high-strength alloy strips and foils with high flatness to meet the needs of strips and foils in consumer electronics, integrated circuits and other fields is an urgent problem to be solved. Summary of the Invention

[0006] To address the aforementioned problems, this invention provides a method for controlling the high flatness of high-strength alloy strips and foils. This method can effectively produce high-strength alloy strips and foils that meet the requirements of precision electronics, aerospace, new energy batteries, medical devices, and other fields in terms of dimensional accuracy and flatness.

[0007] The technical solution of the present invention is: a method for controlling the high flatness of high-strength alloy strip foil, comprising the following steps;

[0008] 1) A precision straightening machine is used to perform the first straightening of the high-strength alloy strip and foil blank to adjust the transverse unevenness of the blank and eliminate longitudinal plate shape defects such as edge waviness, quarter waviness, or center waviness. The first straightening includes at least two rolling passes, after which the strip and foil blank is subjected to stress-relief annealing. The rolling passes are determined based on the thickness δ, width W, and yield strength of the strip and foil blank. Set the tension T to obtain the first straightened foil blank with the required transverse unevenness;

[0009] 2) A precision straightening machine is used to perform a second straightening on the obtained first-straightened foil blank to adjust the longitudinal unevenness of the foil blank and eliminate transverse plate shape defects such as bending or warping. The second straightening includes at least two rolling passes, wherein the foil blank is stress-relief annealed after each rolling pass. The rolling passes are based on the thickness δ, width W, and yield strength of the first-straightened foil blank. Set the tension T to obtain a second straightening foil blank with longitudinal unevenness that meets the requirements;

[0010] 3) The precision straightening machine is used to perform a third straightening on the obtained second-straightened foil blank to adjust the overall unevenness of the foil blank. The third straightening includes at least two rolling passes, wherein the foil blank is stress-relief annealed after each rolling pass. The rolling passes are based on the thickness δ, width W, and yield strength of the second-straightened foil blank. By setting the tension T, a high-strength alloy strip and foil product with overall unevenness that meets the requirements is obtained.

[0011] Preferably, the transverse unevenness of the first straightening strip foil blank is ≤0.2mm / twice the width, and the thickness accuracy tolerance is maintained at ±3μm; the longitudinal unevenness of the second straightening strip foil blank is ≤0.2mm / twice the width, and the thickness accuracy tolerance is maintained at ±3μm; the overall unevenness of the high-strength alloy strip foil finished product is ≤0.1mm / twice the width, and the thickness accuracy tolerance is maintained at ±3μm.

[0012] Preferably, the tension T set for the first and second straightening processes is as follows: inlet tension T0 adjustable range 15-30KN, outlet tension adjustable range 12-25KN, elongation adjustable range 0.3%-0.6%, straightening speed adjustable range 5-15m / min, and work roll reduction of -4.5 to -7.5mm. The crown of the support roller for the tension T in the first straightening process is set according to the shape of the foil blank, and the inclination angle of the bending straightening roller box is 0°. The crowns of the support rollers for the tension T in the second straightening process are 5.0mm, 5.0mm, and 5.0mm respectively. The bending straightening roller box inclination angle is set according to the plate shape of the foil blank in the first straightening. The tension T set for the third straightening is as follows: the inlet tension T0 is adjustable from 10 to 15 KN, the outlet tension is adjustable from 8 to 13 KN, the elongation is adjustable from 0.1% to 0.3%, the straightening speed is adjustable from 15 to 25 m / min, the working roller reduction is -1.5 to -4.5 mm, and the support roller crown is 4.5 to 5.5 mm. The bending straightening roller box inclination angle is set according to the plate shape of the foil blank in the second straightening.

[0013] Preferably, the crown of the support roller for the tension T during the first straightening is set according to the shape of the foil blank, specifically:

[0014] If the plate shape of the foil blank is a single-sided wave, and the wave height is greater than 1.0mm / twice the width, the adjustment range of the support roller crown is 3.0~4.0mm, 4.0~6.0mm, 6.0~7.0mm, 4.0~6.0mm, and 4.0~6.0mm respectively;

[0015] If the foil blank has a double-sided wave pattern, and the wave height is greater than 1.0mm / twice the width, the support roller crown adjustment range is 3.0~4.0mm, 5.0~7.0mm, 6.0~7.0mm, 5.0~7.0mm, and 3.0~4.0mm respectively.

[0016] If the foil blank has a quarter wave shape, and the wave height is greater than 1.0 mm / twice the width, the support roller crown adjustment range is 5.0~7.0 mm, 3.0~4.0 mm, 6.0~7.0 mm, 3.0~4.0 mm, and 5.0~7.0 mm respectively;

[0017] If the plate shape of the foil blank is medium wave, and the wave height is greater than 1.0mm / twice the width, the adjustment range of the support roller crown is 6.0~7.0mm, 5.0~7.0mm, 3.0~4.0mm, 5.0~7.0mm, and 6.0~7.0mm respectively.

[0018] Preferably, the bending straightening roller box inclination angle of the second straightening tension T is set according to the plate shape of the foil blank in the first straightening, specifically:

[0019] If the first straightening of the foil blank is a positive bending, the tilt angle adjustment range of the bending straightening roller box is -5° to -2°.

[0020] If the first straightening of the foil blank is a reverse bending, the tilt angle adjustment range of the bending straightening roller box is 2° to 5°.

[0021] Preferably, the bending straightening roller box inclination angle of the third straightening tension T is set according to the plate shape of the foil blank during the second straightening, specifically:

[0022] If the sheet shape of the foil blank is positively bent during the second straightening, the tilt angle adjustment range of the bending straightening roller box is -2° to 0°.

[0023] If the foil blank is bent in the reverse direction during the second straightening process, the tilt angle adjustment range of the bending straightening roller box is 0° to 2°.

[0024] Preferably, the foil blank is subjected to stress-relief annealing in a protective atmosphere, and the stress-relief annealing temperature is lower than the phase transformation temperature of the high-strength alloy, with an annealing temperature range of 300–450°C.

[0025] A precision straightening machine for implementing the above control method includes a bending straightening roller box, an inlet tension roller group, an outlet tension roller group, and a flatness tester. A protective atmosphere heat treatment box is provided between the outlet tension roller group and the flatness tester for stress-relieving annealing treatment.

[0026] Preferably, the bending straightening roller box 1 is symmetrically provided with three sets of pressure rollers, namely upper working roller 7 and lower working roller 8, upper intermediate roller 9 and lower intermediate roller 10, upper support roller 11 and lower support roller 12, wherein the diameter of upper working roller 7 and lower working roller 8 is 16mm, the accuracy is ±0.002mm, and the hardness is HRC61~63.

[0027] Preferably, five sets of movable wedges are evenly distributed below the lower support roller 12, and the adjustment range of each set of movable wedges is 0 to 10.0 mm, which are used to adjust the convexity of the support roller.

[0028] The advantages of this invention are as follows: This invention uses a precision straightening machine, and through tension straightening combined with stress-relief annealing, the tension parameters of the precision straightening machine are adjusted in three straightening processes to obtain a high-strength alloy strip and foil product with a thickness of δ0.05~1.0mm, a width greater than 300mm, a strength exceeding 1500MPa, a thickness tolerance of ±0.003mm, an unevenness of 0.1mm / twice the width, and a bright and clean surface free from defects such as scratches, folds, peeling, pits, pinholes, and oxidation. During straightening, it is necessary to control the amount of pressure applied by the working rollers, reasonably set the tension, elongation, and straightening speed, adjust the crown of the support rollers and the inclination angle of the bending straightening roller box, and supplement with intermediate stress-relief annealing. Finally, the material is straightened into a high-strength alloy strip and foil with a thickness of δ0.05~1.0mm, a width greater than 300mm, a thickness accuracy tolerance of ±3μm, and an overall flatness of 0.1mm / twice the width. This meets the high-quality requirements of high-flatness, high-strength alloy strip and foil in fields such as precision electronics, aerospace, new energy batteries, and medical devices, ensuring production efficiency and product quality, and facilitating industrial promotion. Attached Figure Description

[0029] Figure 1 This is a schematic diagram of the precision straightening machine used in this invention;

[0030] Figure 2 These are front and left view schematic diagrams of the bending straightening roller box used in this invention;

[0031] Figure 3 This is a schematic diagram showing the orientation relationship between the internal pressure roller and the foil material when adjusting the tilt angle of the bending straightening roller box according to the present invention.

[0032] Figure 4 This is a schematic diagram of common plate shape defects in the initial plate shape of high-strength foil materials;

[0033] Figure 5 The image shows a physical picture of a high-strength alloy strip and foil material with high flatness (thickness δ0.05mm, width 305mm) manufactured according to the above scheme.

[0034] Reference numerals: 1-Bending straightening roller box, 2-Inlet tension roller group, 3-Outlet tension roller group, 4-Protective atmosphere heat treatment box, 5-Flatness tester, 6-High-strength alloy strip foil, 7-Upper working roller, 8-Lower working roller, 9-Upper intermediate roller, 10-Lower intermediate roller, 11-Upper support roller, 12-Lower support roller, 13-1-First movable wedge, 13-2-Second movable wedge, 13-3-Third movable wedge, 13-4-Fourth movable wedge, 13-5-Fifth movable wedge. Detailed Implementation

[0035] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all 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.

[0036] See Figures 1 to 5 This invention employs a precision straightening machine to adjust the flatness of high-strength alloy strip foil, and its structure is as follows: Figure 1 As shown, the system includes a bending straightening roller box 1, an inlet tension roller group 2, an outlet tension roller group 3, a protective atmosphere heat treatment chamber 4, and a flatness detector 5. The bending straightening roller box 1 contains three symmetrically arranged pressure rollers: an upper working roller 7, a lower working roller 8, an upper intermediate roller 9, a lower intermediate roller 10, an upper support roller 11, and a lower support roller 12. The upper working roller 7 and the lower working roller 8 both have a diameter of 16mm, an accuracy of ±0.002mm, and a hardness of HRC61~63. Below the lower support roller 12 are five evenly distributed sets of movable wedges: a first movable wedge 13-1, a second movable wedge 13-2, a third movable wedge 13-3, a fourth movable wedge 13-4, a fifth movable wedge 13-5, and each set of wedges is equipped with a high-precision displacement sensor (accuracy ±0.005mm) and a pressure feedback unit. The inclined angle of the movable wedge is designed to be 45°±30'. The extension amount of each wedge group can be adjusted in real time through the CNC system to adjust the crown of the support roller. The adjustment range of the movable wedge is 0~10.0mm (the distance between the contact point of the movable wedge and the lower support roller relative to the mechanical zero point). The crown of the support roller can be represented by the adjustment amount of the five groups of movable wedges. For example, the extension amount of the first movable wedge 13-1 is 1.1mm, the extension amount of the second movable wedge 13-2 is 2.2mm, the extension amount of the third movable wedge 13-3 is 3.3mm, the extension amount of the fourth movable wedge 13-4 is 4.4mm, and the extension amount of the fifth movable wedge 13-5 is 5.5mm. Then the crown of the support roller is 1.1mm, 2.2mm, 3.3mm, 4.4mm, and 5.5mm.

[0037] A method for controlling the high flatness of high-strength alloy strips and foils includes the following steps;

[0038] 1) A precision straightening machine is used to perform the first straightening of the high-strength alloy strip and foil blank to adjust the transverse unevenness of the blank and eliminate longitudinal plate shape defects such as edge waviness, quarter waviness, or center waviness. The first straightening includes at least two rolling passes, after which the strip and foil blank is subjected to stress-relief annealing. The rolling passes are determined based on the thickness δ, width W, and yield strength of the strip and foil blank. By setting the tension T, a first straightening foil blank with a lateral unevenness ≤0.2mm / twice the width and a thickness accuracy tolerance of ±3μm is obtained.

[0039] The first straightening setting for the precision straightener has the following tension T: inlet tension T0 adjustable range 15~30KN, outlet tension adjustable range 12~25KN, elongation adjustable range 0.3%~0.6%, straightening speed adjustable range 5~15m / min, work roll reduction -4.5~-7.5mm, bending straightening roll box inclination angle 0°, and support roll crown set according to the plate shape of the foil blank, specifically:

[0040] If the plate shape of the foil blank is a single-sided wave, and the wave height is greater than 1.0mm / twice the width, the adjustment range of the support roller crown is 3.0~4.0mm, 4.0~6.0mm, 6.0~7.0mm, 4.0~6.0mm, and 4.0~6.0mm respectively;

[0041] If the foil blank has a double-sided wave pattern, and the wave height is greater than 1.0mm / twice the width, the support roller crown adjustment range is 3.0~4.0mm, 5.0~7.0mm, 6.0~7.0mm, 5.0~7.0mm, and 3.0~4.0mm respectively.

[0042] If the foil blank has a quarter wave shape, and the wave height is greater than 1.0 mm / twice the width, the support roller crown adjustment range is 5.0~7.0 mm, 3.0~4.0 mm, 6.0~7.0 mm, 3.0~4.0 mm, and 5.0~7.0 mm respectively;

[0043] If the plate shape of the foil blank is medium wave, and the wave height is greater than 1.0mm / twice the width, the adjustment range of the support roller crown is 6.0~7.0mm, 5.0~7.0mm, 3.0~4.0mm, 5.0~7.0mm, and 6.0~7.0mm respectively.

[0044] 2) A precision straightening machine is used to perform a second straightening on the obtained first-straightened foil blank to adjust the longitudinal unevenness of the foil blank and eliminate transverse plate shape defects such as bending or warping. The second straightening includes at least two rolling passes, wherein the foil blank is stress-relief annealed after each rolling pass. The rolling passes are based on the thickness δ, width W, and yield strength of the first-straightened foil blank. By setting the tension T, a second straightening foil blank with longitudinal unevenness ≤0.2mm / twice the width and thickness accuracy tolerance maintained at ±3μm is obtained;

[0045] The second straightening setting for the precision straightener has the following tension T: inlet tension T0 adjustable range 15-30KN, outlet tension adjustable range 12-25KN, elongation adjustable range 0.3%-0.6%, straightening speed adjustable range 5-15m / min, work roll reduction -4.5--7.5mm, support roll crowns of 5.0mm, 5.0mm, 5.0mm, 5.0mm, and 5.0mm respectively, and the bending straightening roller box inclination angle is set according to the plate shape of the foil blank from the first straightening, specifically:

[0046] If the first straightening of the foil blank is a positive bending, the tilt angle adjustment range of the bending straightening roller box is -5° to -2°.

[0047] If the first straightening of the foil blank is a reverse bending, the tilt angle adjustment range of the bending straightening roller box is 2° to 5°.

[0048] 3) The precision straightening machine is used to perform a third straightening on the obtained second-straightened foil blank to adjust the overall unevenness of the foil blank. The third straightening includes at least two rolling passes, wherein the foil blank is stress-relief annealed after each rolling pass. The rolling passes are based on the thickness δ, width W, and yield strength of the second-straightened foil blank. By setting the tension T, a high-strength alloy strip and foil product with an overall unevenness of ≤0.1mm / twice the width and a thickness accuracy tolerance of ±3μm is obtained.

[0049] The third straightening setting for the precision straightener has the following tension T: inlet tension T0 adjustable range 10-15KN, outlet tension adjustable range 8-13KN, elongation adjustable range 0.1%-0.3%, straightening speed adjustable range 15-25m / min, work roll reduction -1.5--4.5mm, support roll crown range 4.5-5.5mm, and the bending straightening roll box inclination angle is set according to the plate shape of the foil blank from the second straightening, specifically:

[0050] If the sheet shape of the foil blank is positively bent during the second straightening, the tilt angle adjustment range of the bending straightening roller box is -2° to 0°.

[0051] If the foil blank is bent in the reverse direction during the second straightening process, the tilt angle adjustment range of the bending straightening roller box is 0° to 2°.

[0052] In this invention, the strips and foils after each straightening pass are subjected to stress-relief annealing in a protective atmosphere. The stress-relief annealing temperature is lower than the phase transformation temperature of the high-strength alloy, and the annealing temperature range is 300-450℃. The stress-relief annealing process eliminates the uneven residual stress caused by local plastic deformation inside the high-strength alloy strips and foils, and restores some plasticity, ensuring the geometric stability of the material and reducing the risk of strip breakage in subsequent straightening processes.

[0053] The high-strength alloy strip and foil blank of this invention shall have a total alloy impurity content of no more than 0.04%, wherein the impurities are S, P, Cu, O, N, and H, and their respective weight percentages are S≤0.01%; P≤0.015%; Cu≤0.01%; O≤0.0020%; N≤0.0050%; and H≤0.0001%. Furthermore, the content of A, B, and C types (coarse and fine series) non-metallic inclusions in the high-strength alloy strip and foil blank shall all be ≤1.0, the content of D type (coarse and fine series) non-metallic inclusions shall be ≤1.5, and the total content of non-metallic inclusions shall not exceed grade 1.5.

[0054] This method involves straightening a high-strength alloy strip / foil blank with a thickness of δ 0.05–1.0 mm and an unevenness > 0.1 mm / twice the width three times using a precision straightening machine. The first straightening is mainly used to adjust the lateral unevenness and eliminate longitudinal plate shape defects such as edge waves, quarter waves, and center waves. The second straightening is mainly used to adjust the longitudinal unevenness and eliminate lateral defects such as bending and warping. The third straightening is mainly used to finely adjust the overall unevenness, improve the plate shape quality of the strip / foil, and further reduce the unevenness. The three-stage straightening process requires controlling the amount of pressure applied to the work rolls, appropriately setting the inlet tension, outlet tension, elongation, and straightening speed, adjusting the convexity of the support rolls and the inclination angle of the bending straightening roll box, and supplementing with intermediate stress-relief annealing. The final straightened product is a high-strength alloy strip and foil with a thickness of δ 0.05~1.0mm, a width greater than 300mm, a thickness accuracy tolerance of ±3μm, an unevenness of 0.1mm / twice the width, a surface roughness Ra≤1.0μm, no camber, a bright and clean surface, and no defects such as scratches, folds, peeling, pits, pinholes, or oxidation. Example 1

[0055] The flatness of 17-7PH foil blanks with a thickness δ0.8mm, a width of 320mm, and an unevenness of 1.2mm / twice the width is adjusted. The incoming material conditions are shown in Table 1.

[0056] Table 1 Specifications and performance of 17-7PH foil blanks

[0057]

[0058] Adjust the flatness of the 17-7PH foil blank using the following method:

[0059] 1) The first straightening process involves three straightening passes. The tension parameters for the first straightening pass are: inlet tension 26KN, outlet tension 21KN, elongation 0.54%, straightening speed 12m / min, work roll pressure -7.2mm, support roll crown 3.2mm, 4.5mm, 6.3mm, 4.8mm, 3.4mm, and bending straightening roll box inclination angle 0°. The tension parameters for the second straightening pass are: inlet tension 24KN, outlet tension 20KN, elongation 0.51%, straightening speed 12.5m / min, work roll pressure -6.9mm, and support roll crown 3.4mm, 4.5mm, 6.1mm. 4.8mm, 3.5mm, bending straightening roller box inclination angle 0°, tension parameter settings for the third straightening pass: inlet tension 21KN, outlet tension 18KN, elongation 0.44%, straightening speed 13m / min, work roll pressure -6.3mm, support roll crown 4.2mm, 4.8mm, 5.8mm, 4.9mm, 4.3mm, bending straightening roller box inclination angle 0°. After each straightening pass, the 17-7PH strip foil needs to be stress-relieved annealed in a protective atmosphere chamber at a stress-relief annealing temperature of 350℃ to achieve a transverse unevenness of 0.18mm / twice the width and maintain a thickness accuracy tolerance of ±3μm.

[0060] 2) Second straightening: 3 passes in the straightening path. The tension parameters for the first straightening pass are: inlet tension 21KN, outlet tension 18KN, elongation 0.43%, straightening speed 13m / min, work roll pressure -6.5mm, support roll crown 5.0mm, 5.0mm, 5.0mm, 5.0mm, 5.0mm, 5.0mm, and the bending straightening roll box inclination angle is 4.7°. The tension parameters for the second straightening pass are: inlet tension 20KN, outlet tension 18KN, elongation 0.41%, straightening speed 13m / min, work roll pressure -6.2mm, and support roll crown 5.0mm, 5.0mm, 5.0mm. The straightening roller box has an inclination angle of 4.5°. The tension parameters for the third straightening pass are: inlet tension 19KN, outlet tension 17KN, elongation 0.40%, straightening speed 13.5m / min, work roll pressure -5.8mm, support roll crown 5.0mm, 5.0mm, 5.0mm, 5.0mm, 5.0mm, 5.0mm, and the straightening roller box has an inclination angle of 4.0°. After each straightening pass, the 17-7PH foil strip needs to be stress-relieved annealed in a protective atmosphere chamber at a temperature of 350℃ to achieve a longitudinal unevenness of 0.19mm / twice the width and a thickness accuracy tolerance of ±3μm.

[0061] 3) The third straightening process involves two straightening passes and three straightening passes in total. The tension parameters for the first straightening pass are: inlet tension 14KN, outlet tension 12KN, elongation 0.28%, straightening speed 19m / min, work roll pressure -4.0mm, support roll crown 4.8mm, 5.2mm, 5.3mm, 5.2mm, 4.8mm, and bending straightening roll box inclination angle 1.6°. The tension parameters for the second straightening pass are: inlet tension 14KN, outlet tension 12KN, elongation 0.2%. The straightening speed is 19.5 m / min, the working roll pressure is -3.9 mm, the support roll crown is 4.9 mm, 5.2 mm, 5.2 mm, 5.2 mm, and 4.9 mm, and the bending straightening roller box tilt angle is 1.3°. After each straightening pass, the 17-7PH strip foil needs to be stress-relieved annealed in a protective atmosphere chamber at a temperature of 350°C. This ensures that the overall unevenness of the 17-7PH strip foil reaches 0.1 mm / twice the width, and the thickness accuracy tolerance is maintained at ±3 μm, thus obtaining a 17-7PH strip foil product that meets the requirements. Example 2

[0062] The flatness of the GH4169 foil blank with a thickness of δ0.05mm, a width of 305mm, and an unevenness of 0.8mm / twice the width was adjusted. The incoming material conditions are shown in Table 2.

[0063] Table 2 Specifications and performance of GH4169 foil blank

[0064]

[0065] Adjust the flatness of GH4169 foil blank using the following method:

[0066] 1) The first straightening process involves two straightening passes. The tension parameters for the first straightening pass are: inlet tension 23KN, outlet tension 19KN, elongation 0.41%, straightening speed 10m / min, work roll pressure -5.3mm, support roll crown 5.4mm, 3.7mm, 6.1mm, 3.6mm, 5.8mm, and bending straightening roll box inclination angle 0°. The tension parameters for the second straightening pass are: inlet tension 22KN, outlet tension 18KN. The elongation is 0.36%, the straightening speed is 10m / min, the working roll pressure is -5.1mm, the support roll crown is 5.3mm, 3.8mm, 6.1mm, 3.8mm, and 5.5mm, the bending straightening roll box inclination angle is 0°, and the GH4169 strip foil after each straightening pass needs to be stress-relieved annealed in a protective atmosphere chamber at a temperature of 400℃ to achieve a transverse unevenness of 0.2mm / twice the width and a thickness accuracy tolerance of ±3μm.

[0067] 2) Second straightening: The straightening process is repeated twice. The tension parameters for the first straightening pass are: inlet tension 21KN, outlet tension 17KN, elongation 0.36%, straightening speed 10.5m / min, work roll pressure -5.6mm, support roll crown 5.0mm, 5.0mm, 5.0mm, 5.0mm, 5.0mm, 5.0mm, and bending straightening roll box inclination angle -4.2°. The tension parameters for the second straightening pass are: inlet tension 20KN, outlet tension 17KN. The elongation is 0.35%, the straightening speed is 10.5m / min, the working roll pressure is -5.4mm, the support roll crown is 5.0mm, 5.0mm, 5.0mm, 5.0mm, 5.0mm, and the bending straightening roll box inclination angle is -3.8°. After each straightening pass, the GH4169 strip foil needs to be stress-relieved annealed in a protective atmosphere chamber at a temperature of 400℃ to achieve a longitudinal unevenness of 0.2mm / twice the width and a thickness accuracy tolerance of ±3μm.

[0068] 3) The third straightening process involves two straightening passes. The tension parameters for the first straightening pass are: inlet tension 13KN, outlet tension 10KN, elongation 0.19%, straightening speed 20m / min, work roll pressure -3.9mm, support roll crown 5.2mm, 4.8mm, 5.1mm, 4.8mm, 5.2mm, and bending straightening roll box inclination angle -1.4°. The tension parameters for the second straightening pass are: inlet tension 13KN, outlet tension 10KN, and elongation 0.18%. The straightening speed is 20m / min, the working roll pressure is -3.6mm, the support roll crown is 5.1mm, 4.9mm, 5.1mm, 4.8mm, and 5.1mm, and the bending straightening roll box inclination angle is -1.3°. After each straightening pass, the GH4169 strip foil needs to be stress-relieved annealed in a protective atmosphere chamber at a temperature of 400℃. This ensures that the overall unevenness of the GH4169 strip foil reaches 0.1mm / twice the width, and the thickness accuracy tolerance is maintained at ±3μm, thus obtaining GH4169 strip foil products that meet the requirements.

[0069] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For the apparatus disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the description is relatively simple; relevant parts can be referred to the method section.

[0070] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for controlling the high flatness of high-strength alloy strip foil, characterized in that, include The following steps; 1) A precision straightening machine is used to perform the first straightening of the high-strength alloy strip and foil blank to adjust the transverse unevenness of the blank and eliminate longitudinal plate shape defects such as edge waviness, quarter waviness, or center waviness. The first straightening includes at least two rolling passes, after which the strip and foil blank is subjected to stress-relief annealing. The rolling passes are determined based on the thickness δ, width W, and yield strength of the strip and foil blank. Set the tension T to obtain the first straightened foil blank with the required transverse unevenness; 2) A precision straightening machine is used to perform a second straightening on the obtained first-straightened foil blank to adjust the longitudinal unevenness of the foil blank and eliminate transverse plate shape defects such as bending or warping. The second straightening includes at least two rolling passes, wherein the foil blank is stress-relief annealed after each rolling pass. The rolling passes are based on the thickness δ, width W, and yield strength of the first-straightened foil blank. Set the tension T to obtain a second straightening foil blank with longitudinal unevenness that meets the requirements; 3) The precision straightening machine is used to perform a third straightening on the obtained second-straightened foil blank to adjust the overall unevenness of the foil blank. The third straightening includes at least two rolling passes, wherein the foil blank is stress-relief annealed after each rolling pass. The rolling passes are based on the thickness δ, width W, and yield strength of the second-straightened foil blank. By setting the tension T, a high-strength alloy strip and foil product with the required overall flatness is obtained.

2. The method for controlling the high flatness of high-strength alloy strip and foil materials according to claim 1, characterized in that: The transverse unevenness of the first straightening strip foil blank is ≤0.2mm / twice the width, and the thickness accuracy tolerance is maintained at ±3μm. The longitudinal unevenness of the second straightening strip foil blank is ≤0.2mm / twice the width, and the thickness accuracy tolerance is maintained at ±3μm. The overall unevenness of the high-strength alloy strip foil finished product is ≤0.1mm / twice the width, and the thickness accuracy tolerance is maintained at ±3μm.

3. The method for controlling the high flatness of high-strength alloy strip and foil materials according to claim 1, characterized in that: The tension T set for the first and second straightening processes is as follows: inlet tension T0 adjustable range 15–30 KN, outlet tension adjustable range 12–25 KN, elongation adjustable range 0.3%–0.6%, straightening speed adjustable range 5–15 m / min, and work roll reduction -4.5–-7.5 mm. The support roller crown of the tension T for the first straightening process is set according to the sheet shape of the foil blank, and the bending straightening roller box inclination angle is 0°. The support roller crowns of the tension T for the second straightening process are 5.0 mm, 5.0 mm, and 5.0 mm, respectively. The bending straightening roller box inclination angle is set according to the plate shape of the foil blank in the first straightening; the tension T set for the third straightening is as follows: the inlet tension T0 is adjustable from 10 to 15 KN, the outlet tension is adjustable from 8 to 13 KN, the elongation is adjustable from 0.1% to 0.3%, the straightening speed is adjustable from 15 to 25 m / min, the working roller reduction is -1.5 to -4.5 mm, and the support roller crown is 4.5 to 5.5 mm. The bending straightening roller box inclination angle is set according to the plate shape of the foil blank in the second straightening.

4. The method for controlling the high flatness of high-strength alloy strip and foil materials according to claim 3, characterized in that: The convexity of the support roller for the tension T during the first straightening process is set according to the shape of the foil blank, specifically: If the plate shape of the foil blank is a single-sided wave, and the wave height is greater than 1.0mm / twice the width, the adjustment range of the support roller crown is 3.0~4.0mm, 4.0~6.0mm, 6.0~7.0mm, 4.0~6.0mm, and 4.0~6.0mm respectively; If the foil blank has a double-sided wave pattern, and the wave height is greater than 1.0mm / twice the width, the support roller crown adjustment range is 3.0~4.0mm, 5.0~7.0mm, 6.0~7.0mm, 5.0~7.0mm, and 3.0~4.0mm respectively. If the foil blank has a quarter wave shape, and the wave height is greater than 1.0 mm / twice the width, the support roller crown adjustment range is 5.0~7.0 mm, 3.0~4.0 mm, 6.0~7.0 mm, 3.0~4.0 mm, and 5.0~7.0 mm respectively; If the plate shape of the foil blank is medium wave, and the wave height is greater than 1.0mm / twice the width, the adjustment range of the support roller crown is 6.0~7.0mm, 5.0~7.0mm, 3.0~4.0mm, 5.0~7.0mm, and 6.0~7.0mm respectively.

5. The method for controlling the high flatness of high-strength alloy strip and foil materials according to claim 3, characterized in that: The bending straightening roller box inclination angle of the second straightening tension T is set according to the plate shape of the foil blank in the first straightening, specifically: If the first straightening of the foil blank is a positive bending, the tilt angle adjustment range of the bending straightening roller box is -5° to -2°. If the sheet shape of the foil blank is reverse-bent during the first straightening, the tilt angle adjustment range of the bending straightening roller box is 2° to 5°.

6. The method for controlling the high flatness of high-strength alloy strip and foil materials according to claim 3, characterized in that: The bending straightening roller box inclination angle of the third straightening tension T is set according to the plate shape of the foil blank in the second straightening, specifically: If the sheet shape of the foil blank is positively bent during the second straightening, the tilt angle adjustment range of the bending straightening roller box is -2° to 0°. If the foil blank is bent in the reverse direction during the second straightening process, the tilt angle adjustment range of the bending straightening roller box is 0° to 2°.

7. The method for controlling the high flatness of high-strength alloy strip and foil materials according to claim 1, characterized in that: The foil blank is subjected to stress-relief annealing in a protective atmosphere. The stress-relief annealing temperature is lower than the phase transformation temperature of the high-strength alloy, and the annealing temperature range is 300-450℃.

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