An oil grinding agent, a pickling pretreatment method and a pickling process suitable for ultra-thin invar plate

Abstract

The present application relates to a kind of oil grinding agent suitable for ultra-thin invar alloy plate, pickling pretreatment method and pickling process, belong to the field of metal material surface treatment, at least one of the problems such as incomplete removal of existing direct pickling process, high risk of matrix overcorrosion, low pickling efficiency and poor surface quality uniformity is solved.One kind of oil grinding agent suitable for ultra-thin invar alloy plate, the oil grinding agent includes mineral oil and extreme pressure agent, the mass ratio of mineral oil and extreme pressure agent is (8-12):1.The present application realizes efficient stripping loose oxide layer, reduces pickling chemical burden, avoids matrix overcorrosion, improves overall efficiency, homogenizes initial surface state, and guarantees final treatment uniformity.

Description

Technical Field

[0001] This invention relates to the field of surface treatment technology for metal materials, and in particular to an oil abrasive, a pretreatment method for pickling, and a pickling process suitable for ultra-thin Invar alloy plates. Background Technology

[0002] Invar alloys are a key basic material for manufacturing high-precision electronic components. To meet the miniaturization requirements of electronic products, their sheet metal is developing towards ultra-thinness. However, after pre-processing such as hot rolling and annealing, a complex oxide layer forms on the surface of these ultra-thin sheets, which must be completely removed. This oxide layer differs from common alloys, exhibiting unique stability and greater difficulty in removal due to its high nickel content: its composition is more stable, it is extremely tightly bonded to the matrix, and it is difficult to remove uniformly; more importantly, the removal process must avoid damaging the matrix, otherwise it will destroy the alloy's unique low thermal expansion characteristics, requiring higher standards of process control.

[0003] Currently, chemical pickling is commonly used in industry to directly remove the oxide layer from metal surfaces. However, when traditional pickling processes are applied to Invar alloy sheets that possess both ultra-thin characteristics and the aforementioned complex oxide layers, the following prominent problems arise: incomplete oxide layer removal and substrate over-corrosion coexist; the surface quality uniformity of the treated sheet is poor; and the overall pickling efficiency is low, with insufficient process controllability. These problems severely restrict the application of ultra-thin Invar alloy sheets in high-reliability electronics fields.

[0004] Therefore, providing a process that does not damage the substrate, can efficiently remove the oxide layer on the surface of this type of alloy, and improves pickling efficiency is of great significance for the subsequent rolling processing of this type of alloy sheet and ensuring the stable performance of Invar alloy thin material. Summary of the Invention

[0005] Based on the above analysis, the present invention aims to provide an oil abrasive, a pretreatment method for pickling, and a pickling process suitable for ultra-thin Invar alloy plates, in order to solve at least one of the problems existing in the current direct pickling process, such as incomplete removal of oxide layer, high risk of substrate over-corrosion, low pickling efficiency, and poor surface quality uniformity.

[0006] The objective of this invention is achieved through the following technical solution:

[0007] This invention provides an oil abrasive suitable for ultra-thin Invar alloy sheets, the oil abrasive comprising mineral oil and extreme pressure agent, wherein the mass ratio of mineral oil to extreme pressure agent is (8-12):1.

[0008] Furthermore, the mineral oil is selected from one or more of naphthenic mineral oil, intermediate-based mineral oil, paraffinic mineral oil, and light white oil; and / or,

[0009] The extreme pressure agent is selected from one or more of isobutylene sulfide, dibenzyl disulfide, phosphate ester amine salt, and borate ester.

[0010] Furthermore, the oil abrasive is suitable for ultra-thin Invar alloy sheets with a thickness of ≤0.3mm.

[0011] This invention provides a pre-treatment method for pickling of ultra-thin Invar alloy sheets, comprising the following steps:

[0012] Surface pretreatment: Clean the ultra-thin Invar alloy sheet using a degreasing agent;

[0013] Oil polishing: The surface of the pre-treated ultra-thin Invar alloy sheet is polished using the aforementioned oil polishing agent;

[0014] Rinsing after oil grinding: Use deionized water to rinse and remove residues after oil grinding.

[0015] Furthermore, in the surface pretreatment, the degreasing agent comprises sodium hydroxide, sodium carbonate, and a nonionic surfactant, wherein the mass ratio of sodium hydroxide, sodium carbonate, and nonionic surfactant is (4-6):(2-4):(1-3); and / or,

[0016] The nonionic surfactant is selected from one or more of fatty alcohol polyoxyethylene ethers, polyoxyethylene castor oil, alkyl glycosides, and alkylphenol polyoxyethylene ethers; and / or,

[0017] The working mass concentration of the degreasing agent is 8%-15%.

[0018] Furthermore, in the surface pretreatment, the temperature of the degreasing agent used is 40-55°C, and the surface pretreatment time is 8-10 minutes.

[0019] Furthermore, the oil milling process employs a silicon carbide milling head with a particle size of 800-1200 mesh.

[0020] Furthermore, the process parameters for the oil milling treatment include: an oil milling pressure of 0.1-0.3 MPa; and / or,

[0021] The grinding speed is 1-3 m / min; and / or,

[0022] The polishing process is repeated 1-2 times; and / or,

[0023] During the oil milling process, the oil milling agent is replenished with a spray rate of 5-10 L / h.

[0024] Furthermore, the post-oil mill rinsing is performed using deionized water at a pressure of 0.6-0.9 MPa; and / or,

[0025] The rinsing time is 2-4 minutes; and / or,

[0026] The flushing water flow velocity is 1.0-1.5 m / s; and / or,

[0027] The post-oil grinding rinsing process uses symmetrical multi-hole nozzles to rinse the surface of the Invar alloy sheet after oil grinding.

[0028] This invention provides a pickling process suitable for ultra-thin Invar alloy sheets, comprising the following steps:

[0029] Pre-pickling treatment: The ultra-thin Invar alloy sheet is treated using the aforementioned pre-pickling treatment method;

[0030] Pickling treatment: The ultra-thin Invar alloy sheet after pickling pretreatment is immersed in a pickling solution for pickling, wherein the pickling solution is a mixed aqueous solution of hydrochloric acid and nitric acid.

[0031] Compared with the prior art, the present invention can achieve at least one of the following beneficial effects:

[0032] To address the aforementioned issues, this invention proposes a pretreatment process prior to pickling, which includes oil grinding and provides an oil grinding medium. The aim is to remove the loose oxide layer and contaminants on the surface of the Invar alloy sheet through the pretreatment process, providing an optimized basis for uniform surface condition and reactivity in the subsequent pickling process, thereby establishing a phased and synergistic pickling process system of "physical pretreatment - chemical pickling".

[0033] The oil-grinding agent provided by this invention, through a specific ratio of mineral oil and extreme pressure agent, constitutes a core medium for efficient and controllable oil-grinding treatment. Its mechanism of action and effects are specifically reflected in the following aspects:

[0034] (1) Efficiently removes the loose oxide layer, laying the foundation for thorough removal:

[0035] Oil abrasives effectively and uniformly physically peel away the loose outer oxide layer on the surface of Invar alloy sheets by forming a medium layer that combines lubrication and micro-cutting functions. This step directly removes the outer "burden" that needs to be treated by subsequent pickling, laying the physical foundation for the complete removal of the oxide layer.

[0036] (2) Reduce the chemical burden of pickling and avoid over-corrosion of the substrate:

[0037] By using a specific ratio of mineral oil and extreme pressure agent to synergistically work together, an oil abrasive can be used to achieve efficient and controllable physical stripping of the loose oxide layer on the surface while effectively protecting the Invar alloy substrate. This eliminates the need for excessively long processing times or excessively high concentrations of pickling solution in subsequent pickling processes to dissolve this oxide layer, significantly reducing the risk of over-corrosion of the substrate due to excessive pickling reaction or excessive time.

[0038] (3) Restructuring the division of labor in the process significantly improves overall efficiency:

[0039] By using a specific ratio of oil abrasive, the traditional single chemical dissolution mode is reconstructed into a division of labor system of "physical pretreatment (oil abrasion) to quickly remove the loose layer + chemical treatment (acid washing) to directionally remove the dense layer". This fully leverages the speed advantage of physical treatment and the selectivity advantage of chemical methods, significantly shortening the overall process cycle and improving processing efficiency.

[0040] (4) Homogenize the initial surface state to ensure uniformity in the final processing:

[0041] The uniform lubricating film formed during the grinding process by using a specific ratio of oil abrasive provides a starting interface with a uniform surface condition and reactivity for subsequent pickling, enabling the pickling reaction to proceed uniformly across the entire board surface. This effectively solves the problem of poor uniformity caused by inconsistent surface conditions in direct pickling.

[0042] Based on the oil abrasive provided by this invention, this invention provides a pre-treatment method for pickling of ultra-thin Invar alloy plates, the advantages of which are:

[0043] (5) Achieve gradient removal of oxide layer and surface activation:

[0044] The pretreatment method sequentially removes contaminants through surface pretreatment, peels off the loose oxide layer through oil grinding, and removes residual oil grinding media by rinsing after oil grinding, forming a complete "cleaning-peeling-finishing" process. This provides an optimized interface with oxide layer thinning, surface activation, and uniformity for subsequent pickling, and lays a good foundation for the complete removal of the oxide layer.

[0045] (6) A matrix protection chain is formed throughout the entire pretreatment process by avoiding chemical corrosion through weak alkaline pretreatment, preventing mechanical damage through physical treatment under the protection of oil abrasive, and eliminating interface interference through thorough rinsing. This system allows subsequent pickling to be carried out under milder conditions, systematically preventing over-corrosion of the matrix.

[0046] (7) The pretreatment method has clear objectives and is highly efficient in several steps, which shortens the overall time of the pickling preparation and subsequent pickling processes.

[0047] (8) The pretreatment method described above includes pretreatment to ensure uniform cleanliness, oil grinding to remove the loose oxide layer on the outer layer and homogenize the surface morphology, and post-rinsing to ensure interface consistency. This provides a highly uniform and predictable standard reaction interface for pickling, ensuring the stability of the processing quality between batches.

[0048] In this invention, the above-described technical solutions can be combined with each other to achieve more preferred combinations. Other features and advantages of this invention will be set forth in the following description, and some advantages may become apparent from the description or be learned by practicing the invention. The objects and other advantages of this invention can be realized and obtained from what is particularly pointed out in the description and drawings. Attached Figure Description

[0049] The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Throughout the drawings, the same reference numerals denote the same parts.

[0050] Figure 1 A schematic flowchart of an acid pickling process for ultra-thin Invar alloy sheets provided in an embodiment of the present invention;

[0051] Figure 2 This is a comparison chart of the roughness test results for the example and the comparative example;

[0052] Figure 3 This is a comparison chart of the oxide layer removal rates of the examples and comparative examples;

[0053] Figure 4 Macroscopic images of ultra-thin Invar alloy sheets obtained by the pickling process provided in this embodiment of the invention;

[0054] Figure 5 The EBSD (electron backscatter diffraction) analysis results of the ultrathin Invar alloy plate obtained by the pickling process provided in the embodiment of the present invention are shown in (a) KAM diagram (intragranular orientation difference diagram) and (b) Euler diagram (grain orientation distribution diagram).

[0055] Figure 6 The EBSD (electron backscatter diffraction) analysis results of the ultrathin Invar alloy plate obtained by the pickling process provided in Comparative Example 4-1 are shown in (a) KAM diagram (internal orientation difference diagram) and (b) Euler diagram (grain orientation distribution diagram).

[0056] Figure 7 The electron microscopy analysis results of the ultrathin Invar alloy plate obtained after "oil grinding treatment + pickling treatment" in the pickling process provided in the embodiment of the present invention are shown in (a) selected area electron diffraction pattern and (b) electron microscopy morphology image.

[0057] Figure 8 The electron microscopy analysis results of the ultrathin Invar alloy plate obtained after "oil grinding" in the pickling process provided in the embodiment of the present invention are shown in (a) selected area electron diffraction pattern and (b) electron microscopy morphology image.

[0058] Figure 9SEM image of the ultrathin Invar alloy sheet obtained by the pickling process provided in this embodiment of the invention;

[0059] Figure 10 SEM image of the ultra-thin Invar alloy sheet obtained by the pickling process provided in Comparative Example 1. Detailed Implementation

[0060] Preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings, which form part of this application and are used together with the embodiments of the present invention to illustrate the principles of the present invention, but are not intended to limit the scope of the present invention.

[0061] In analyzing the aforementioned problems of the prior art, the inventors found that the traditional direct pickling process, when dealing with the composite oxide layer structure of Invar alloy, requires the simultaneous removal of both the loose outer layer and the dense inner layer of oxide layer, which makes process control difficult and makes it difficult to take into account the corrosion sensitivity and easy deformation characteristics of ultra-thin plates.

[0062] Based on this, the inventors proposed a phased treatment approach: adding an oil abrasion pretreatment step before pickling. This physical method removes the outer loose oxide layer in advance, combined with a specially developed oil abrasive, creating favorable conditions for subsequent pickling. Based on this division of labor—"physical pretreatment + chemical pickling"—the proposed pickling process allows each step to perform its specific function, working together to completely remove the oxide layer.

[0063] In a first aspect, the present invention provides an oil abrasive suitable for ultra-thin Invar alloy plates, the oil abrasive comprising mineral oil and extreme pressure agent, wherein the mass ratio of mineral oil to extreme pressure agent is (8-12):1.

[0064] For example, the mass ratio of the mineral oil to the extreme pressure agent is 8:1, 9:1, 9.2:1, 9.5:1, 9.8:1, 10:1, 10.2:1, 10.5:1, 10.8:1, 11:1, or 12:1; preferably (9 to 11):1.

[0065] Specifically, the mineral oil is selected from one or more of naphthenic mineral oil, intermediate mineral oil, paraffinic mineral oil, and light white oil; preferably, it is paraffinic mineral oil.

[0066] Preferably, the kinematic viscosity (40°C) of the mineral oil is 10–30 mm. 2 / s, viscosity index ≥95; flash point ≥150℃; pour point ≤-15℃; moisture ≤0.03ppm; acid value ≤0.05mg KOH / g.

[0067] For example, the naphthenic mineral oil includes Kunlun KN4010 naphthenic base oil, Great Wall 45# naphthenic base oil, and PetroChina Karamay KN4050 naphthenic base oil.

[0068] For example, the intermediate base mineral oil includes Sinopec 150SN intermediate base oil, CNOOC HVI250 intermediate base oil, and Kunlun KL-200 intermediate lubricating oil base oil.

[0069] For example, the paraffinic mineral oil includes Kunlun SN150 paraffinic base oil, Great Wall L-AN46 paraffinic system oil, and Sinopec Maoming 100SN paraffinic process oil.

[0070] For example, the light white oil includes Kunlun L-10 light white oil, Great Wall HC-15 light white oil, and Sinopec Jinling 10# industrial grade light white oil.

[0071] Specifically, the extreme pressure agent is selected from one or more of isobutylene sulfide, dibenzyl disulfide, phosphate ester amine salt, and borate ester; preferably isobutylene sulfide.

[0072] For example, isobutylene sulfide has R-CH2-S X The structure of -CH2-R (R is isobutyl, x is usually 1-4, preferably x = 2 or 3).

[0073] For example, the phosphate ester amine salt is selected from one or more of tricresyl phosphate amine salt T306, triphenyl phosphate amine salt T307, and dioctyl phosphate amine salt T309.

[0074] For example, the borate ester is selected from one or more of tributyl borate T361, triisooctyl borate T362, and dipropyl borate T363.

[0075] By specifying the exact types and optimizing the ratios of mineral oil and extreme pressure agents, a dedicated oil-based grinding system with improved lubricity, extreme pressure properties, and cooling performance was constructed. This system can achieve efficient removal of the loose oxide layer on the surface of Invar alloys while ensuring effective protection of the substrate under ultra-thin (≤0.3 mm, e.g., 0.1–0.3 mm) conditions, thus establishing an optimized balance between removal efficiency and substrate integrity.

[0076] In some embodiments, the abrasive is suitable for ultra-thin Invar alloy sheets with a thickness of ≤0.3 mm (e.g., 0.1 to 0.3 mm).

[0077] Secondly, the present invention provides a pre-treatment method for pickling of ultra-thin Invar alloy sheets, comprising the following steps:

[0078] Surface pretreatment: Clean the ultra-thin Invar alloy sheet using a degreasing agent;

[0079] Oil polishing: The surface of the pretreated ultrathin Invar alloy sheet is polished using the oil polishing compound as described in the first aspect;

[0080] Rinsing after oil grinding: Use deionized water to rinse and remove residues after oil grinding.

[0081] It is understood that the surface pretreatment includes: using a special degreasing agent adapted to Invar alloy material to clean the surface of the ultra-thin Invar alloy sheet to be treated, removing oil and dust adhering to the surface. The degreasing agent has the characteristics of being non-corrosive to the substrate and having low residue, thus avoiding damage to the surface microstructure of the ultra-thin Invar alloy sheet.

[0082] Specifically, in the surface pretreatment, the degreasing agent comprises sodium hydroxide, sodium carbonate and a nonionic surfactant, and the mass ratio of sodium hydroxide, sodium carbonate and nonionic surfactant is (4-6):(2-4):(1-3).

[0083] For example, the degreasing agent used comprises sodium hydroxide, sodium carbonate and a nonionic surfactant, with the remainder being water; the mass ratio of the sodium hydroxide, sodium carbonate and the nonionic surfactant is (4, 4.5, 4.8, 5, 5.2, 5.5, 6): (2, 2.5, 2.8, 3, 3.2, 3.5, 4): (1, 1.5, 1.8, 2, 2.2, 2.5, 3).

[0084] Preferably, the degreasing agent used comprises sodium hydroxide, sodium carbonate and a nonionic surfactant, wherein the mass ratio of sodium hydroxide, sodium carbonate and nonionic surfactant is (4.5-5.5):(2.5-3.5):(1.5-2.5).

[0085] For example, the nonionic surfactant is selected from one or more combinations of fatty alcohol polyoxyethylene ether, polyoxyethylene castor oil, alkyl glycoside, and alkylphenol polyoxyethylene ether; preferably fatty alcohol polyoxyethylene ether.

[0086] For example, the fatty alcohol polyoxyethylene ether is selected from one or more of AEO-7 (fatty alcohol polyoxyethylene ether-7), AEO-9 (fatty alcohol polyoxyethylene ether-9), and AEO-15 (fatty alcohol polyoxyethylene ether-15). For example, the carbon chain length of the fatty alcohol is C12-C14. The number AEO-15 represents an average of 15 ethylene oxide (EO) units added to each fatty alcohol molecule.

[0087] For example, the polyoxyethylene castor oil is selected from one or more of EL-20 (polyoxyethylene (20) castor oil), EL-40 (polyoxyethylene (40) castor oil), and EL-60 (polyoxyethylene (60) castor oil).

[0088] For example, the alkyl glycoside is selected from one or more of APG0810 (C8-C10 alkyl glycoside), APG1214 (C12-C14 alkyl glycoside), and APG0814 (C8-C14 alkyl glycoside).

[0089] For example, the alkylphenol polyoxyethylene ether is selected from one or more of OP-10 (octylphenol polyoxyethylene ether-10), NP-10 (nonylphenol polyoxyethylene ether-10), and DP-12 (dodecylphenol polyoxyethylene ether-12).

[0090] Specifically, in the surface pretreatment, the temperature of the degreasing agent used is 40-55°C, and the surface pretreatment time is 8-10 minutes.

[0091] For example, the temperature of the degreasing agent used is 40°C, 42°C, 45°C, 47°C, 50°C, 52°C, or 55°C; preferably 45°C to 50°C.

[0092] For example, the surface pretreatment time is 8.0 min, 8.5 min, 8.7 min, 9.0 min, 9.2 min, 9.5 min, or 10.0 min; preferably 8.5 to 9.5 min.

[0093] Specifically, the working mass concentration of the degreasing agent is 8%-15%.

[0094] For example, the working mass concentration of the degreasing agent is 8%, 9%, 10%, 11%, 12%, 13%, 14%, or 15%; preferably 9% to 12%.

[0095] It should be noted that in the pretreatment, a specific ratio of sodium hydroxide, sodium carbonate, and nonionic surfactant is used to achieve efficient degreasing under alkaline conditions. Simultaneously, the degreasing agent avoids the risk of corrosion to the Invar alloy surface. The optimized range of working mass concentration ensures cleaning effectiveness while minimizing chemical residue, providing a chemically clean and intact substrate for subsequent treatment. By controlling the surface pretreatment temperature and time, the thermal and chemical impacts on the ultra-thin Invar alloy sheet are minimized while ensuring the complete dissolution and removal of oil and contaminants, preventing sheet warping or microstructural changes during the pretreatment stage.

[0096] It is understood that the oil polishing process includes: polishing the surface of the pre-treated ultra-thin Invar alloy sheet using oil polishing equipment.

[0097] Specifically, in the oil milling process, the oil milling tension control range is 20-30KN. For example, the oil milling tension is 20KN, 22KN, 24KN, 25KN, 26KN, 27KN, ​​28KN, 29KN, or 30KN.

[0098] Preferably, the oil mill tension is 24-28KN.

[0099] Specifically, the oil mill tension control method is as follows: a constant tension closed-loop control system is adopted, which monitors the tension change of the plate in real time through a tension sensor to ensure that the tension fluctuation range is ≤±2KN.

[0100] Specifically, the process parameters for the oil milling treatment include: an oil milling pressure of 0.1-0.3 MPa. For example, the oil milling pressure is 0.1 MPa, 0.15 MPa, 0.18 MPa, 0.2 MPa, 0.25 MPa, or 0.3 MPa; preferably 0.15-0.2 MPa.

[0101] Specifically, the process parameters for the oil grinding treatment include a grinding speed of 1-3 m / min. For example, the grinding speeds are 1.0 m / min, 1.5 m / min, 1.8 m / min, 2.0 m / min, 2.2 m / min, 2.5 m / min, and 3.0 m / min; preferably 1.5 to 2.5 m / min.

[0102] Specifically, the process parameters for the oil grinding treatment include: 1-2 grinding cycles.

[0103] It should be noted that the specific ratio of oil abrasive components forms a stable lubricating protective film during the polishing process, effectively reducing the coefficient of friction and significantly minimizing surface phase transformation damage caused by frictional overheating, while maintaining the integrity of the matrix grain structure. By precisely controlling key parameters such as oil polishing pressure and polishing speed, a processing environment with uniform stress distribution was established, successfully suppressing local stress concentration and keeping the warpage deformation of ultra-thin sheets within the allowable range of the process, ensuring that the product has excellent flatness and dimensional stability. Through the synergistic control of the oil abrasive components and oil polishing process parameters, the dual goals of efficient removal of the oxide layer (loose outer layer) and matrix protection were achieved.

[0104] Specifically, the oil grinding process uses a silicon carbide grinding head with a particle size of 800-1200 mesh. For example, the particle size of the silicon carbide grinding head is 800 mesh, 900 mesh, 1000 mesh, 1100 mesh, or 1200 mesh; preferably 1000-1200 mesh.

[0105] Specifically, during the oil milling process, the oil milling agent is replenished with a spray rate of 5-10 L / h. For example, the spray rate is 5 L / h, 6 L / h, 6.5 L / h, 7 L / h, 7.5 L / h, 8 L / h, 9 L / h, or 10 L / h; preferably 6-8 L / h.

[0106] It should be noted that by using a silicon carbide grinding head, compared to a traditional rigid grinding head, the elastic modulus of the silicon carbide grinding head is reduced, which can avoid extrusion deformation of ultra-thin plates. By controlling the grinding head particle size to precisely match the oxide layer thickness, it can be ensured that it only acts on the loose oxide outer layer during processing and does not touch the substrate surface, thus avoiding extrusion deformation of ultra-thin plates. During the grinding process, oil abrasive is replenished by spraying, and by controlling the spray volume, the lubrication and cooling effect of the oil abrasive can be guaranteed, while avoiding oil residue affecting the subsequent pickling efficiency. Through the coordinated control of the grinding head material, particle size, and spray parameters, an optimized balance between cleaning efficiency and substrate protection is achieved.

[0107] It is understandable that rinsing is performed after oil polishing to remove residues from the surface of the board, including residual oil polishing agents and substances that have been peeled off from the surface of the board through the oil polishing process, such as debris from the loose oxide layer.

[0108] It is understood that the "loose oxide layer" mentioned in this invention refers to an oxide layer with a porosity ≥25% and a microhardness of 200-350 HV. In some embodiments, the thickness of the loose oxide layer on the surface of the ultra-thin Invar alloy sheet ranges from 0.2 to 1.5 μm.

[0109] Specifically, the post-oil mill rinsing is performed using deionized water at a pressure of 0.6-0.9 MPa; the rinsing time is 2-4 minutes; and the rinsing water flow rate is 1.0-1.5 m / s.

[0110] Preferably, the post-oil grinding rinsing uses symmetrical multi-hole nozzles to rinse the surface of the Invar alloy sheet after oil grinding.

[0111] For example, the orifice diameter of the multi-hole nozzle is 0.3-1.0 mm; the orifices are uniformly distributed on the nozzle, and the orifice density can be 10-30 orifices / dm³. 2 The angle between the spray axis of the upper and lower nozzles and the normal to the surface of the board can be independently set from 10° to 45°; preferably from 10° to 30°.

[0112] It is understandable that in oil grinding, by selecting silicon carbide grinding heads and controlling the synergistic process parameters such as their particle size, oil grinding pressure, grinding speed, number of grinding cycles, and the amount of oil grinding agent sprayed and replenished, precise and controllable peeling of loose oxide layers can be achieved. While ensuring efficient removal of the surface oxide layer, continuous lubrication and cooling effectively avoid substrate damage, deformation, and surface overheating caused by friction overheating or stress concentration, thereby ensuring the stability, repeatability, and process controllability of the oil grinding process.

[0113] Furthermore, in the post-oil polishing rinsing process, by controlling the rinsing pressure, water flow rate, and rinsing time, it is possible to achieve efficient removal of oil polishing agent residue while controlling the impact energy of the fluid on the board, thus maintaining the flatness and quality of the ultra-thin board.

[0114] It should be noted that, in order to evaluate the effect of oil grinding, SEM was used to observe the cross-section of the plate before and after oil grinding, measure the percentage difference in oxide layer thickness, and calculate the loose oxide layer removal rate. The pretreatment method for pickling provided in this embodiment of the invention (mainly oil grinding) can achieve a loose oxide layer removal rate of ≥98%; Loose oxide layer removal rate = ((Oxide layer thickness before oil grinding - Residual oxide layer thickness after oil grinding) / Loose oxide layer thickness before oil grinding) × 100%.

[0115] Thirdly, the present invention provides a pickling process suitable for ultra-thin Invar alloy sheets, comprising the following steps:

[0116] Pre-pickling treatment: The ultra-thin Invar alloy sheet is treated using the pre-pickling treatment method described in the second aspect;

[0117] Pickling treatment: The ultra-thin Invar alloy sheet after pickling pretreatment is immersed in a pickling solution for pickling, wherein the pickling solution is a mixed aqueous solution of hydrochloric acid and nitric acid.

[0118] Compared with existing technologies, the pickling process provided by this invention has the following advantages:

[0119] By employing a synergistic process system of "oil grinding + mixed pickling," a balance is achieved between efficient oxide layer removal and substrate protection. This process first removes the loose oxide layer from the surface through oil grinding, significantly reducing the burden on subsequent pickling. Then, a hydrochloric acid-nitric acid mixed acid system is used to target and remove the dense oxide layer, overcoming the bottleneck of traditional pickling processes that easily lead to over-corrosion and excessive surface roughness in ultra-thin Invar alloy substrates. This staged treatment strategy ensures thorough removal of the oxide layer from the surface of the ultra-thin Invar alloy sheet while effectively avoiding the over-corrosion problems common in traditional single pickling processes by shortening the contact time between the strong acid and the substrate and reducing corrosion intensity. This helps ensure the surface integrity and compositional stability of the ultra-thin Invar alloy sheet, guaranteeing the quality and performance of the strip.

[0120] By employing a step-by-step process of first removing the loose outer oxide layer through oil grinding and then removing the dense inner oxide layer through acid pickling, the oxide layer is removed efficiently, which improves the pickling efficiency compared to the traditional single-mode process.

[0121] It is understood that the "dense oxide layer" mentioned in this invention refers to an oxide layer with a porosity ≤8% and a microhardness of 450-650 HV. In some embodiments, the thickness of the dense oxide layer on the surface of the ultra-thin Invar alloy sheet is 0.05-0.5 μm.

[0122] The pickling process provided by this invention results in an ultra-thin Invar alloy sheet with a surface roughness Ra≤0.2μm; an oxide layer removal rate≥98%; good crystal structure integrity; and XRD testing shows no lattice distortion or phase transformation.

[0123] It is understood that after the pre-pickled treatment, pickling is performed using a pickling solution with a specific formula to achieve targeted removal of the dense oxide layer, thus overcoming the bottleneck that traditional pickling easily leads to over-corrosion of ultra-thin Invar alloy substrates and excessive surface roughness.

[0124] Specifically, the pickling solution is a mixed aqueous solution of hydrochloric acid and nitric acid. Based on the total mass of the pickling solution, the pickling solution contains 7%-18% hydrochloric acid and 0.5%-3.0% nitric acid by mass percentage.

[0125] Specifically, in the pickling solution, the mass ratio of hydrochloric acid to nitric acid is 2.3:1 to 36:1.

[0126] For example, the pickling solution contains hydrochloric acid at a mass percentage of 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, or 18%; preferably 8%-16%.

[0127] For example, the pickling solution contains 0.5%, 0.7%, 1.0%, 1.2%, 1.5%, 1.7%, 2.0%, 2.2%, 2.5%, 2.7%, or 3.0% by mass; preferably 1.0%-2.5%.

[0128] Preferably, in the pickling solution, the mass ratio of hydrochloric acid to nitric acid is (4:1) to (20:1).

[0129] For example, in the pickling solution, the mass ratio of hydrochloric acid to nitric acid is 3:1, 4:1, 5:1, 6:1, 7:1, 8:1, 9:1, 10:1, 11:1, 12:1, 13:1, 14:1, 15:1, 16:1, 17:1, 18:1, 19:1, 20:1, 25:1, 30:1, or 33:1.

[0130] Furthermore, the mass ratio of hydrochloric acid to nitric acid is (4:1) to (13:1).

[0131] In some preferred embodiments, the pickling solution contains 9%-15% hydrochloric acid and 1.2%-2.3% nitric acid by mass, with the balance being water, based on the total mass of the pickling solution.

[0132] Specifically, in the pickling process, the pickling solution is prepared by mixing a hydrochloric acid solution with a concentration of 10wt.%-20wt.% and a nitric acid solution with a concentration of 5wt.%-10wt.% at a volume ratio of (3-5):1.

[0133] For example, in the preparation of the pickling solution, the concentration of the hydrochloric acid solution is 10 wt.%, 12 wt.%, 14 wt.%, 16 wt.%, 18 wt.%, or 20 wt.%.

[0134] For example, in the preparation of the pickling solution, the concentration of the nitric acid solution is 5 wt.%, 6 wt.%, 7 wt.%, 8 wt.%, 9 wt.%, or 10 wt.%.

[0135] For example, the volume ratio of the hydrochloric acid solution to the nitric acid solution is 3:1, 3.5:1, 4:1, 4.5:1, or 5:1.

[0136] Preferably, the pickling solution is prepared by mixing a hydrochloric acid solution with a concentration of 12wt.%-18wt.% and a nitric acid solution with a concentration of 7wt.%-9wt.% at a volume ratio of (3.5-4.5):1.

[0137] Specifically, the pickling temperature is 30-50℃; for example, the pickling temperature is 30℃, 35℃, 40℃, 45℃, or 50℃; preferably 35-45℃.

[0138] Specifically, the pickling time is 5-15 minutes. For example, the pickling time is 5 minutes, 7 minutes, 9 minutes, 11 minutes, 13 minutes, or 15 minutes; preferably 7 to 11 minutes.

[0139] For example, the pickling temperature fluctuation is maintained at ≤±2℃ by boiler steam heating. During pickling, slight shaking is incorporated to promote the removal of reaction products. This slight shaking is achieved by a mechanical device driving the pickling tank to perform periodic reciprocating motion; specifically, the parameters of this periodic reciprocating motion are controlled as follows: amplitude 8-12cm, frequency 1-1.5Hz (i.e., 60-90 reciprocations per minute). It can be understood that the pickling tank (or the frame in which the sheet is placed) performs periodic reciprocating motion back and forth (or left and right) in the horizontal direction. Preferably, the periodic reciprocating motion is performed back and forth (along the length of the strip) in the horizontal direction.

[0140] It should be noted that by employing a hydrochloric acid-nitric acid mixed acid system and controlling process parameters, efficient removal of the dense oxide layer and reliable protection of the substrate material were achieved. Specifically, the scientifically proportioned hydrochloric acid-nitric acid mixed acid system maintained the hydrogen ion concentration within a suitable low range. This concentration range ensured sufficient dissolution kinetics for the oxide layer, guaranteeing efficient removal of the dense oxide layer, while also reducing the substrate corrosion rate, thus meeting the sensitive requirements of ultra-thin Invar alloy plates for corrosion depth. Hydrochloric acid penetrates and peels off the oxide layer, while nitric acid, through its oxidizing properties, forms a nanoscale protective film on the substrate surface. The synergistic effect of these two components establishes an effective corrosion inhibition mechanism. Controlling the pickling temperature prevents excessive temperature from exposing the substrate grains. For example, boiler steam heating maintains temperature fluctuations ≤ ±2℃, effectively preventing reaction rate instability caused by temperature fluctuations. Controlling the pickling time ensures both complete dissolution of the dense oxide layer and prevents substrate damage caused by excessively long processing times. By synergistically controlling pickling temperature and time, an optimized balance is achieved between efficient removal of the oxide layer and complete protection of the substrate. While ensuring thorough removal of the oxide layer, the substrate loss is strictly controlled to within ≤1.5μm.

[0141] It should be noted that, in order to evaluate the effect of the pickling treatment provided by the present invention, the thickness difference of the plate before and after pickling is measured using a high-precision thickness gauge to determine the corrosion depth of the substrate after pickling. The pickling treatment method provided in the embodiments of the present invention achieves a substrate corrosion depth ≤0.6μm.

[0142] To address the issues of secondary oxidation and surface adsorption of impurities in ultra-thin Invar alloys after pickling, the pickling process provided by this invention further includes: post-pickling treatment; the post-pickling treatment includes: after the pickling treatment, sequentially washing, passivating, and drying the surface of the ultra-thin Invar alloy sheet.

[0143] It should be noted that by designing a closed-loop post-treatment process of "water washing-passivation-drying", a triple guarantee of "no residue-antioxidation-no deformation" is achieved, resulting in an ultra-thin Invar alloy sheet with no oxide layer on the surface and a complete structure.

[0144] Specifically, the post-treatment water washing uses deionized water with a conductivity ≤5μS / cm. By optimizing the water quality conditions of the water washing process, secondary pollution is avoided, and the surface quality of the Invar alloy sheet after pickling is better guaranteed.

[0145] Specifically, the water washing temperature is 25-35℃, and the washing time is 3-8 minutes. By controlling the water washing temperature and time, the pickling solution is effectively removed while preventing problems such as thermal deformation of the board.

[0146] For example, the washing temperature is 25°C, 27°C, 29°C, 31°C, 33°C, or 35°C; the washing time is 3 min, 4 min, 5 min, 6 min, 7 min, or 8 min. Preferably, the washing temperature is 27–31°C, and the washing time is 4–6 min.

[0147] Specifically, "washing time" or "rinsing time" refers to the total effective washing time experienced by any point (or unit) on the board from the time it enters the washing area to the time it leaves the washing area.

[0148] Preferably, the pH value of the board surface after washing is 6-7, and the residual acid content on the surface is ≤0.01g / m³. 2 By controlling the pH and the amount of residual acid on the surface, an ideal clean surface is provided for subsequent processes.

[0149] It is understandable that a dense passivation film is formed on the surface of the plate through a passivation reaction. This passivation film has a strong bond with the Invar alloy substrate and does not affect the thermal expansion coefficient of the plate, effectively preventing secondary oxidation of the plate during storage and subsequent processing.

[0150] Specifically, the passivation solution used in the passivation process is an aqueous solution of trivalent chromium or an aqueous solution of sodium chromate with a mass concentration of 5%-10%.

[0151] In some preferred embodiments, the passivation solution used is an aqueous solution of trivalent chromium, wherein the trivalent chromium aqueous solution contains Cr 3+ The molar concentration is 0.2–0.8 mol / L; for example, Cr 3+ The molar concentrations are 0.3 mol / L, 0.4 mol / L, 0.5 mol / L, 0.6 mol / L, 0.7 mol / L, and 0.8 mol / L; preferably 0.4–0.6 mol / L.

[0152] For example, the trivalent chromium aqueous solution is selected from one or a combination of several of the following: chromium sulfate (Cr2(SO4)3) aqueous solution, chromium chloride (CrCl3) aqueous solution, chromium phosphate (CrPO4) hydrochloric acid solution, chromium oxalate (Cr2(C2O4)3) aqueous solution, chromium sulfate-phosphoric acid complex aqueous solution, chromium chloride-hydroxyethylidene diphosphonic acid complex aqueous solution, and chromium nitrate (Cr(NO3)3) aqueous solution.

[0153] In a preferred embodiment, the trivalent chromium aqueous solution is a chromium sulfate-phosphoric acid composite aqueous solution, wherein Cr... 3+ The molar concentration of phosphoric acid is 0.2–0.8 mol / L, and the concentration range of phosphoric acid is 10–20 g / L (mass concentration 0.98%–2.02%).

[0154] In a preferred embodiment, the chromium phosphate (CrPO4) hydrochloric acid solution contains Cr... 3+ The molar concentration of the HCl is 0.2–0.8 mol / L; the mass concentration of the HCl is 5%–12%, preferably 8%–10%.

[0155] In a preferred embodiment, in the chromium chloride-hydroxyethylidene diphosphonic acid composite aqueous solution, Cr 3+ The molar concentration of hydroxyethylidene diphosphonic acid is 0.2–0.8 mol / L; the concentration of hydroxyethylidene diphosphonic acid is 0.5–3 g / L, preferably, the concentration of hydroxyethylidene diphosphonic acid is 1.5–2 g / L.

[0156] Specifically, the passivation temperature is 40-60℃, and the passivation time is 2-5 minutes.

[0157] For example, the passivation temperatures are 40°C, 45°C, 50°C, 55°C, and 60°C. The passivation times are 2 min, 3 min, 3.5 min, 4 min, and 5 min.

[0158] Preferably, the passivation temperature is 45–55°C, and the passivation time is 3–4 minutes.

[0159] By controlling the concentration of the passivation solution and the passivation process parameters, a dense passivation film of suitable thickness can be formed on the surface of Invar alloy sheets. This passivation film layer is firmly bonded to the substrate and does not affect the thermal expansion characteristics of the material. It can effectively prevent secondary oxidation of the sheet during storage and subsequent processing, ensuring the long-term stability of the product.

[0160] After the passivation step is completed, the waste passivation liquid can be treated by chemical precipitation. After solid-liquid separation, the precipitate is disposed of in accordance with hazardous waste regulations, and the supernatant is discharged safely after meeting the standards. Alternatively, after filtration and purification to remove impurities, the consumed passivation liquid can be replenished to achieve recycling and reduce costs.

[0161] Specifically, after passivation, a passivation solution cleaning step is also included; the surface of the Invar alloy plate is rinsed with deionized water at a pressure of 0.2-0.4 MPa, and the water flow rate during rinsing is controlled at 0.4-0.7 m / s; the rinsing time is 3-5 min.

[0162] It is understandable that in passivation solution cleaning, using ultra-low pressure deionized water and controlling the water flow rate can prevent damage to the passivation film layer; for example, by using symmetrical multi-hole nozzles to make the water flow into a fine mist, the contact area is increased and the impact force is dispersed, so as to achieve the cleaning of the surface of ultra-thin Invar alloy plates with ultra-low pressure deionized water.

[0163] It should be noted that by controlling the water flow parameters during the post-passivation cleaning process, the passivation film layer is effectively protected from damage while ensuring the effective removal of surface residues.

[0164] Specifically, a smooth strip conveying mechanism is installed within the washing (rinsing) device to ensure that both sides of the Invar alloy sheet (strip) are evenly rinsed. For example, the strip conveying speed is 0.8–1.0 m / s.

[0165] Preferably, in the passivation solution cleaning process, the water flow is made into a fine mist by using a multi-hole nozzle with symmetrical upper and lower parts, which increases the contact area and disperses the impact force.

[0166] For example, in passivation solution cleaning, the nozzle uses nozzles with an aperture of 0.15 mm to 0.3 mm, arranged in a honeycomb pattern with 30 to 50 holes per square centimeter; under a working pressure of 0.2 MPa to 0.4 MPa, a fine mist flow with an average droplet diameter of 50 μm to 120 μm is formed; the distance between the nozzle end face and the workpiece surface is maintained within the range of 100 mm to 200 mm, and the strip is cleaned by continuous spraying.

[0167] Specifically, the drying temperature is 60-80℃. Exemplarily, the drying temperature is 60℃, 65℃, 70℃, 75℃, or 80℃; preferably, the drying temperature is 65-75℃.

[0168] Specifically, the air velocity during the drying process is 1.0-1.5 m / s. For example, the air velocity during the drying process is 1.0 m / s, 1.1 m / s, 1.2 m / s, 1.3 m / s, 1.4 m / s, or 1.5 m / s. Preferably, the air velocity during the drying process is 1.2 to 1.4 m / s.

[0169] Specifically, the drying time is 8-15 minutes. Examples include 8 minutes, 9 minutes, 10 minutes, 11 minutes, 13 minutes, and 15 minutes. Preferably, the drying time is 10-13 minutes.

[0170] By controlling the drying temperature, time, and airflow parameters, a balance was achieved between efficient moisture removal and material dimensional stability. This avoided localized high temperatures that could cause shrinkage and deformation of the ultra-thin sheet, ensuring that there was no moisture residue on the sheet surface and that the flatness error remained at the initial process level.

[0171] Specifically, after the drying step, the obtained ultrathin Invar alloy sheet is evaluated, and the evaluation includes:

[0172] The surface roughness of the plate is tested, and the acceptable standard is Ra≤0.2μm; and / or,

[0173] The oxide layer removal rate of the board material is tested, and the pass standard is an oxide layer removal rate ≥ 98%; and / or,

[0174] The integrity of the crystal structure of the plate is tested, and the pass standard is the absence of lattice distortion or phase transition.

[0175] Furthermore, when all the above indicators meet the requirements, the pickled ultra-thin Invar alloy sheet is judged to meet the electronic grade material standard.

[0176] For example, detecting the surface roughness of the plate includes: using a surface roughness meter to detect the surface roughness (Ra) of the pickled ultra-thin Invar alloy plate, selecting N detection points (N≥5) along the "parallel rolling direction + perpendicular rolling direction" on the surface of the pickled plate, and detecting the surface roughness at each point to avoid ignoring the local roughness differences caused by the anisotropy of rolling of the ultra-thin plate, requiring that Ra≤0.2μm for all detection points.

[0177] For example, detecting the oxide layer removal rate of the plate includes: observing the surface morphology of the ultra-thin Invar alloy plate before and after pickling using a scanning electron microscope (SEM), comparing the cross-sections of the un-pickled and pickled samples of the same batch, measuring the oxide layer thickness before pickling and the residual oxide layer thickness after pickling, and calculating the oxide layer removal rate according to the formula: Oxide layer removal rate = ((Oxide layer thickness before pickling - Residual oxide layer thickness after pickling) / Oxide layer thickness before pickling) × 100%. This avoids the subjective error of traditional visual judgment and requires an oxide layer removal rate of ≥98%.

[0178] For example, detecting the crystal structure integrity of the plate includes: using an X-ray diffractometer (XRD) to analyze the crystal structure of the pickled ultrathin Invar alloy plate, comparing it with the standard Invar alloy XRD pattern without pickling, detecting whether lattice distortion or phase transformation occurs, ensuring that the crystal structure of the plate is intact after pickling, and that its extremely low coefficient of thermal expansion is not affected, thus meeting the stringent requirements of precision instruments for dimensional stability.

[0179] When using X-ray diffraction (XRD) analysis, the standard Invar alloy (Ni36) XRD pattern without acid washing is used as the benchmark: the position deviation of the characteristic diffraction peaks (such as 2θ = 43.5°, 50.7°, 74.5°) of the acid-washed plate is ≤ ±0.1°, which is judged as no lattice distortion; no new diffraction peaks (such as diffraction peaks related to nickel oxide and iron oxide) appear, and the original characteristic diffraction peaks do not split, broaden or have abnormal intensity decay (relative intensity deviation ≤ 5%), which is judged as no phase transition.

[0180] The composition of the standard Invar alloy (Ni36) comprises, by mass percentage: Ni: 36%, with the balance being Fe and unavoidable impurities.

[0181] It should be noted that after post-processing, a multi-dimensional evaluation system was established that includes surface quality, oxide layer removal effect, and material structural integrity, thus achieving a comprehensive assessment of the pickling process effect. When all test indicators meet the preset standards, it can be determined that the ultra-thin Invar alloy sheet meets the requirements for electronic-grade materials.

[0182] The "ultra-thin Invar alloy sheet" mentioned in this invention refers to an Invar alloy sheet with a thickness of ≤0.3mm. For example, the thickness of the ultra-thin Invar alloy sheet is 0.1-0.3mm. For instance, the thickness of the ultra-thin Invar alloy sheet is 0.1mm, 0.15mm, 0.20mm, 0.25mm, or 0.30mm.

[0183] In some embodiments, the chemical composition of the "ultra-thin Invar alloy sheet" contains Ni: 35.0%-37.0% by mass, with the balance being Fe and unavoidable impurities.

[0184] In some embodiments, the chemical composition of the "ultra-thin Invar alloy sheet" by mass percentage is Ni: 35.5%–36.5%, C: 0.001%–0.03%, Mn: 0.2%–0.5%, Si: 0–0.1%, Al: 0–0.03%, Cr: 0–0.1%, Nb: 0–0.02%, with the balance being Fe and other unavoidable impurities.

[0185] The technical solution of the present invention will be further described in detail below with reference to specific embodiments and comparative examples.

[0186] Example 1:

[0187] This embodiment provides an oil abrasive suitable for ultra-thin Invar alloy sheets, composed of paraffin-based mineral oil (i.e., Kunlun SN150 paraffin-based base oil) and sulfurized isobutylene (i.e., sulfurized isobutylene R-CH2-S). X -CH2-R, x=2, R is isobutyl) are compounded in a mass ratio of 10:1.

[0188] Example 2:

[0189] This embodiment provides an oil abrasive suitable for ultra-thin Invar alloy sheets, composed of paraffin-based mineral oil (i.e., Kunlun SN150 paraffin-based base oil) and sulfurized isobutylene (i.e., sulfurized isobutylene R-CH2-S). X -CH2-R, x=2, R is isobutyl) are compounded in a mass ratio of 8:1.

[0190] Example 3:

[0191] This embodiment provides an oil abrasive suitable for ultra-thin Invar alloy sheets, composed of paraffin-based mineral oil (i.e., Kunlun SN150 paraffin-based base oil) and sulfurized isobutylene (i.e., sulfurized isobutylene R-CH2-S). X -CH2-R, x=2, R is isobutyl) are compounded in a mass ratio of 12:1.

[0192] Example 4:

[0193] This embodiment provides an oil abrasive suitable for ultra-thin Invar alloy plates, composed of naphthenic mineral oil (i.e., KN4010 naphthenic base oil) and sulfurized isobutylene (i.e., sulfurized isobutylene R-CH2-S). X -CH2-R, x=3, R is isobutyl) are compounded in a mass ratio of 10:1.

[0194] Example 5:

[0195] This embodiment provides an oil abrasive suitable for ultra-thin Invar alloy plates, composed of intermediate-base mineral oil (i.e., Sinopec 150SN intermediate-base oil) and sulfurized isobutylene (i.e., sulfurized isobutylene R-CH2-S). X -CH2-R, x=2, R is isobutyl) are compounded in a mass ratio of 10:1.

[0196] Example 6:

[0197] This embodiment provides an oil abrasive suitable for ultra-thin Invar alloy sheets, composed of light white oil (i.e., Kunlun L-10 light white oil) and sulfurized isobutylene (i.e., sulfurized isobutylene R-CH2-S). X -CH2-R, x=3, R is isobutyl) are compounded in a mass ratio of 10:1.

[0198] Example 7:

[0199] This embodiment provides an oil abrasive suitable for ultra-thin Invar alloy plates, consisting of a mixture of paraffinic mineral oil (i.e., Great Wall L-AN46 paraffinic system oil) and naphthenic mineral oil (i.e., Great Wall 45# naphthenic base oil) in a 1:1 mass ratio, and sulfurized isobutylene (i.e., sulfurized isobutylene R-CH2-S). X -CH2-R, x=2, R is isobutyl) are compounded in a mass ratio of 10:1.

[0200] Example 8

[0201] This embodiment provides an oil abrasive suitable for ultra-thin Invar alloy plates, which is compounded from paraffin-based mineral oil (i.e., Great Wall L-AN46 paraffin-based system oil) and dibenzyl disulfide at a mass ratio of 10:1.

[0202] Example 9

[0203] This embodiment provides an oil abrasive suitable for ultra-thin Invar alloy plates, which is compounded from paraffin-based mineral oil (i.e., Sinopec Maoming 100SN paraffin-based process oil) and phosphate ester amine salt (tricresol phosphate amine salt T306) in a mass ratio of 10:1.

[0204] Example 10

[0205] This embodiment provides an oil abrasive suitable for ultra-thin Invar alloy plates, which is compounded from paraffin-based mineral oil (i.e., Sinopec Maoming 100SN paraffin-based process oil) and borate ester (i.e., tributyl borate T361) in a mass ratio of 10:1.

[0206] Example 11

[0207] This embodiment provides an oil abrasive suitable for ultra-thin Invar alloy plates, which is compounded from naphthenic mineral oil (i.e., Kunlun KN4010 naphthenic base oil) and phosphate ester amine salt (i.e., triphenyl phosphate amine salt T307) in a mass ratio of 11:1.

[0208] Example 12

[0209] This embodiment provides an oil abrasive suitable for ultra-thin Invar alloy plates, which is compounded from intermediate base mineral oil (i.e., CNOOC HVI250 intermediate base oil) and dibenzyl disulfide in a mass ratio of 9:1.

[0210] Comparative Example 1

[0211] This comparative example provides an oil abrasive composed of paraffin-based mineral oil (i.e., Kunlun SN150 paraffin-based base oil) and sulfurized isobutylene (i.e., sulfurized isobutylene R-CH2-S). X -CH2-R, x=2, R is isobutyl) are compounded in a mass ratio of 20:1.

[0212] Comparative Example 2

[0213] This comparative example provides an oil abrasive composed of paraffin-based mineral oil (i.e., Kunlun SN150 paraffin-based base oil) and sulfurized isobutylene (i.e., sulfurized isobutylene R-CH2-S). X -CH2-R, x=2, R is isobutyl) are compounded in a mass ratio of 5:1.

[0214] Application Example 1

[0215] This application example uses the same pickling process (specific steps and parameters are as follows), only changing the oil polishing agent used in the oil polishing treatment (step S2), which are the oil polishing agents in Examples 1-12 and Comparative Examples 1-2, respectively, to evaluate its effect.

[0216] The pickling process described in this application example includes the following steps:

[0217] S1, Surface pretreatment

[0218] The ultra-thin Invar alloy sheet (thickness = 0.1 mm) to be treated was immersed in a degreasing agent solution. The degreasing agent contained sodium hydroxide, sodium carbonate, and fatty alcohol polyoxyethylene ether (i.e., fatty alcohol polyoxyethylene ether-9, AEO-9). The mass ratio of sodium hydroxide, sodium carbonate, and fatty alcohol polyoxyethylene ether was 5:3:2, and the balance was water. The degreasing agent concentration was 10%, the degreasing agent temperature was 50°C, and the surface pretreatment time was 9 min.

[0219] S2, Oil grinding treatment

[0220] The pretreated board was subjected to oil grinding using a silicon carbide grinding head (1000 mesh). The oil grinding agent used in the oil grinding was selected from the oil grinding agents provided in Examples 1-12 and Comparative Examples 1-2. The oil grinding pressure was 0.2 MPa, the grinding speed was 2.0 m / min, and the number of grinding cycles was 1. During the grinding process, the oil grinding agent was replenished with a spray rate of 8 L / h. The oil grinding tension was 26 KN.

[0221] S3. Rinse after oil grinding.

[0222] Deionized water at a pressure of 0.8 MPa was used to rinse the oil-polished board through symmetrical multi-hole nozzles at a water flow rate of 1.2 m / s for 3 minutes to ensure complete removal of the oil polishing agent.

[0223] S4, pickling treatment

[0224] The rinsed substrate is immersed in an pickling solution prepared by mixing a 15 wt.% hydrochloric acid solution and an 8 wt.% nitric acid solution at a volume ratio of 4:1. The pickling solution contains 12% hydrochloric acid and 1.6% nitric acid by mass, with the remainder being water. The mass ratio of hydrochloric acid to nitric acid is 7.5:1. The pickling temperature is 40℃, and the pickling time is 8 minutes. During the pickling process, a mechanical device drives the pickling tank to perform periodic reciprocating motion (amplitude 10 cm, frequency 1.2 Hz) to promote the removal of reaction products, ensuring complete removal of the oxide layer while strictly controlling the substrate loss to ≤1 μm.

[0225] S5, Post-processing

[0226] S51. Water washing: Use deionized water with a conductivity ≤5μS / cm, at a temperature of 30℃, for a washing time of 5 minutes; after washing, the pH value of the board surface is 6.5, and the residual acid content on the board surface is 0.008g / m³. 2 ;

[0227] S52, Passivation: The washed plate is immersed in a chromium sulfate-phosphoric acid composite aqueous solution, wherein Cr... 3+ The molar concentration of the compound was 0.5 mol / L, and the concentration of phosphoric acid was 15 g / L; the passivation temperature was 50℃, and the passivation time was 3 min.

[0228] S53. Passivation solution cleaning: Deionized water with a pressure of 0.3MPa and a flow rate of 0.7m / s is used for rinsing through a multi-hole nozzle with symmetrical upper and lower parts for 4 minutes; at the same time, a strip conveying mechanism is set in the water washing device, with a strip conveying speed of 0.8m / s to ensure that both sides of the strip can be rinsed evenly.

[0229] S54. Drying: Dry the board at a drying temperature of 70℃ and a wind speed of 1.2m / s for 12 minutes.

[0230] S6, Evaluation

[0231] The following tests and evaluations were performed on the pickled ultrathin Invar alloy sheets:

[0232] Surface roughness: The surface roughness (Ra) of the pickled ultra-thin Invar alloy sheet was measured using a surface roughness meter. Five test points were selected on the surface of the pickled sheet along the parallel rolling direction and the perpendicular rolling direction, and the surface roughness at each point was measured. The Ra value of each test point was obtained.

[0233] Oxide layer removal rate: The surface morphology of ultra-thin Invar alloy plates before and after pickling was observed using scanning electron microscopy (SEM). The cross-sections of unpickled and pickled samples from the same batch were compared. The oxide layer thickness before pickling and the residual oxide layer thickness after pickling were measured. The oxide layer removal rate was calculated using the formula (Oxide layer removal rate = ((Oxide layer thickness before pickling - Residual oxide layer thickness after pickling) / Oxide layer thickness before pickling) × 100%, avoiding the subjective error of traditional visual judgment.

[0234] Structural integrity: When using X-ray diffraction (XRD) analysis, the standard Invar alloy (Ni36) XRD pattern without acid washing is used as the benchmark: if the position deviation of the characteristic diffraction peaks (such as 2θ = 43.5°, 50.7°, 74.5°) of the acid-washed plate is ≤ ±0.1°, it is judged to be without lattice distortion; if no new diffraction peaks (such as diffraction peaks related to nickel oxide and iron oxide) appear, and the original characteristic diffraction peaks do not split, broaden, or have abnormal intensity decay (relative intensity deviation ≤ 5%), it is judged to be without phase transformation.

[0235] Table 1. Test results of the examples and comparative examples (Group 1)

[0236]

[0237] Example 13

[0238] This embodiment provides a pre-treatment method for pickling of ultra-thin Invar alloy plates. The steps are the same as S1 to S3 in Application Example 1 and the oiling agent described in Example 1 is used. The difference is in the parameters in step S1. Specifically, the degreasing agent contains sodium hydroxide, sodium carbonate and fatty alcohol polyoxyethylene ether (i.e., fatty alcohol polyoxyethylene ether-7, AEO-7). The mass ratio of sodium hydroxide, sodium carbonate and fatty alcohol polyoxyethylene ether is 4:2:1, and the balance is water. The mass concentration of the degreasing agent is 8%, the degreasing agent temperature is 40°C, and the surface pretreatment time is 8 min.

[0239] This embodiment provides a pickling process for ultra-thin Invar alloy sheets, including: pre-pickling treatment: the ultra-thin Invar alloy sheets are treated using the pre-pickling treatment method described in this embodiment; then, steps S4 to S6 as described in Application Example 1 are performed.

[0240] Example 14

[0241] This embodiment provides a pre-treatment method for pickling of ultra-thin Invar alloy plates. The steps are the same as S1 to S3 in Application Example 1 and the oiling agent described in Example 1 is used. The difference is in the parameters in step S1. Specifically, the degreasing agent contains sodium hydroxide, sodium carbonate and fatty alcohol polyoxyethylene ether (i.e., fatty alcohol polyoxyethylene ether-15, AEO-15). The mass ratio of sodium hydroxide, sodium carbonate and fatty alcohol polyoxyethylene ether is 6:4:3, and the balance is water. The mass concentration of the degreasing agent is 15%, the degreasing agent temperature is 55°C, and the surface pretreatment time is 10 min.

[0242] This embodiment provides a pickling process for ultra-thin Invar alloy sheets, including: pre-pickling treatment: the ultra-thin Invar alloy sheets are treated using the pre-pickling treatment method described in this embodiment; then, steps S4 to S6 as described in Application Example 1 are performed.

[0243] Example 15

[0244] This embodiment provides a pre-treatment method for pickling of ultra-thin Invar alloy plates. The steps are the same as S1 to S3 in Application Example 1 and the oil abrasive described in Example 1 is used. The difference is in the parameters in step S2. Specifically, a silicon carbide grinding head (800 mesh) is used to perform oil abrasive treatment on the pretreated plate. The oil abrasive pressure is 0.1 MPa, the grinding speed is 1.0 m / min, and the number of grinding times is 2. During the grinding process, the oil abrasive is replenished with a spray rate of 5 L / h.

[0245] This embodiment provides a pickling process for ultra-thin Invar alloy sheets, including: pre-pickling treatment: the ultra-thin Invar alloy sheets are treated using the pre-pickling treatment method described in this embodiment; then, steps S4 to S6 as described in Application Example 1 are performed.

[0246] Example 16

[0247] This embodiment provides a pre-treatment method for pickling of ultra-thin Invar alloy plates. The steps are the same as S1 to S3 in Application Example 1 and the oil abrasive described in Example 1 is used. The difference is in the parameters in step S2. Specifically, a silicon carbide grinding head (1200 mesh) is used to perform oil abrasive treatment on the pretreated plate. The oil abrasive pressure is 0.3 MPa, the grinding speed is 3.0 m / min, and the number of grinding times is 1. During the grinding process, the oil abrasive is replenished with a spray rate of 10 L / h.

[0248] This embodiment provides a pickling process for ultra-thin Invar alloy sheets, including: pre-pickling treatment: the ultra-thin Invar alloy sheets are treated using the pre-pickling treatment method described in this embodiment; then, steps S4 to S6 as described in Application Example 1 are performed.

[0249] Example 17

[0250] This embodiment provides a pre-treatment method for pickling ultra-thin Invar alloy plates. The steps are the same as S1 to S3 in Application Example 1 and the oil abrasive described in Example 1 is used. The difference is that in the oil abrasive treatment, the oil abrasive tension is 20KN; in step S3, deionized water with a pressure of 0.6MPa is used to rinse the oil-rubbed plate through a multi-hole nozzle with symmetrical upper and lower parts. The water flow rate is 1.0m / s and the rinsing time is 2min.

[0251] This embodiment provides a pickling process for ultra-thin Invar alloy sheets, including: pre-pickling treatment: the ultra-thin Invar alloy sheets are treated using the pre-pickling treatment method described in this embodiment; then, steps S4 to S6 as described in Application Example 1 are performed.

[0252] Example 18

[0253] This embodiment provides a pre-treatment method for pickling ultra-thin Invar alloy plates. The steps are the same as S1 to S3 in Application Example 1 and the oil abrasive described in Example 1 is used. The difference is that in the oil abrasive treatment, the oil abrasive tension is 30KN. In step S3, deionized water with a pressure of 0.9MPa is used to rinse the oil-rubbed plate through a multi-hole nozzle with symmetrical upper and lower parts. The water flow rate is 1.5m / s and the rinsing time is 4min.

[0254] This embodiment provides a pickling process for ultra-thin Invar alloy sheets, including: pre-pickling treatment: the ultra-thin Invar alloy sheets are treated using the pre-pickling treatment method described in this embodiment; then, steps S4 to S6 as described in Application Example 1 are performed.

[0255] Table 2 Test Results of Examples (Second Group)

[0256]

[0257] Example 19-1

[0258] This embodiment provides a pickling process suitable for ultra-thin Invar alloy plates. The pickling process described in this embodiment is the same as that described in Application Example 1 and uses the oil abrasive described in Example 1. The difference is that in the pickling process, the pickling solution contains 9.2% hydrochloric acid and 2.3% nitric acid by mass percentage, with the balance being water. The mass ratio of hydrochloric acid to nitric acid is 4:1.

[0259] Example 19-2

[0260] This embodiment provides a pickling process suitable for ultra-thin Invar alloy plates. The pickling process described in this embodiment is the same as that described in Application Example 1 and uses the oil abrasive described in Example 1. The difference is that in the pickling process, the pickling solution contains 15% hydrochloric acid and 1.2% nitric acid by mass percentage, with the balance being water. The mass ratio of hydrochloric acid to nitric acid is 12.5:1.

[0261] Example 19-3

[0262] This embodiment provides a pickling process suitable for ultra-thin Invar alloy plates. The pickling process described in this embodiment is the same as that described in Application Example 1 and uses the oil abrasive described in Example 1. The difference is that in the pickling process, the pickling solution contains 18% hydrochloric acid and 0.5% nitric acid by mass, with the balance being water. The mass ratio of hydrochloric acid to nitric acid is 36:1.

[0263] Example 19-4

[0264] This embodiment provides a pickling process suitable for ultra-thin Invar alloy plates. The pickling process described in this embodiment is the same as that described in Application Example 1 and uses the oil abrasive described in Example 1. The difference is that in the pickling process, the pickling solution contains 7.0% hydrochloric acid and 3.0% nitric acid by mass percentage, with the balance being water. The mass ratio of hydrochloric acid to nitric acid is 2.3:1.

[0265] Example 20-1

[0266] This embodiment provides a pickling process suitable for ultra-thin Invar alloy plates. The pickling process described in this embodiment is the same as that described in Application Example 1 and uses the oil abrasive described in Example 1. The difference is that in the pickling process, the pickling temperature is 30°C and the pickling time is 15 minutes.

[0267] Example 20-2

[0268] This embodiment provides a pickling process suitable for ultra-thin Invar alloy plates. The pickling process described in this embodiment is the same as that described in Application Example 1 and uses the oil abrasive described in Example 1. The difference is that in the pickling process, the pickling temperature is 50°C and the pickling time is 5 minutes.

[0269] Example 20-3

[0270] This embodiment provides a pickling process suitable for ultra-thin Invar alloy plates. The pickling process described in this embodiment is the same as that described in Application Example 1 and uses the oil abrasive described in Example 1. The difference is that in the pickling process, the amplitude is 6cm and the frequency is 0.8Hz.

[0271] Example 20-4

[0272] This embodiment provides a pickling process suitable for ultra-thin Invar alloy plates. The pickling process described in this embodiment is the same as that described in Application Example 1 and uses the oil abrasive described in Example 1. The difference is that in the pickling process, the amplitude is 15cm and the frequency is 2.0Hz.

[0273] Example 20-5

[0274] This embodiment provides a pickling process suitable for ultra-thin Invar alloy plates. The pickling process described in this embodiment is the same as that described in Application Example 1 and uses the oil abrasive described in Example 1. The difference is that the pickling process does not use periodic reciprocating motion.

[0275] Example 21

[0276] This embodiment provides a pickling process suitable for ultra-thin Invar alloy sheets. The pickling process described in this embodiment is the same as that described in Application Example 1 and uses the oil abrasive described in Example 1. The difference is that in the passivation step of the post-treatment, the passivation solution used is an aqueous solution of chromium phosphate (CrPO4) dissolved in hydrochloric acid. In the aqueous solution of chromium phosphate (CrPO4) dissolved in hydrochloric acid, Cr... 3+ The molar concentration of the active ingredient was 0.2 mol / L, the mass concentration of hydrochloric acid (HCl) was 8%, the passivation temperature was 60℃, and the passivation time was 2 min.

[0277] Example 22

[0278] This embodiment provides a pickling process suitable for ultra-thin Invar alloy sheets. The pickling process described in this embodiment is the same as that described in Application Example 1 and uses the oil abrasive described in Example 1. The difference is that the passivation step in the post-treatment uses a chromium chloride-hydroxyethylidene diphosphonic acid composite aqueous solution. In the chromium chloride-hydroxyethylidene diphosphonic acid composite aqueous solution, Cr... 3+ The molar concentration of the passivation solution is 0.8 mol / L, and the concentration of hydroxyethylidene diphosphonic acid is 2 g / L. In the passivation solution cleaning step after passivation, deionized water with a pressure of 0.4 MPa is used for rinsing, and the water flow rate during rinsing is controlled at 0.4 m / s.

[0279] Example 23

[0280] This embodiment provides a pickling process suitable for ultra-thin Invar alloy sheets. The pickling process described in this embodiment is the same as that described in Application Example 1 and uses the oil abrasive described in Example 1. The difference is that the thickness of the ultra-thin Invar alloy sheet to be treated is 0.2 mm.

[0281] Example 24

[0282] This embodiment provides a pickling process suitable for ultra-thin Invar alloy sheets. The pickling process described in this embodiment is the same as that described in Application Example 1 and uses the oil abrasive described in Example 1. The difference is that the thickness of the ultra-thin Invar alloy sheet to be treated is 0.3 mm.

[0283] Comparative Example 3

[0284] This comparative example provides an acid pickling process, which is the same as the acid pickling process described in Application Example 1, except that it lacks the oil grinding treatment and the rinsing step after oil grinding. The acid pickling treatment and post-treatment steps are performed directly after the surface pretreatment.

[0285] Comparative Example 4-1

[0286] This comparative example provides an acid pickling process. This comparative example is the same as the acid pickling process described in Application Example 1, and the oil abrasive used is the oil abrasive provided in Example 1. The difference is that in the acid pickling process, a single hydrochloric acid solution with a mass concentration of 25% is used as the pickling solution.

[0287] Comparative Example 4-2

[0288] This comparative example provides an acid pickling process. This comparative example is the same as the acid pickling process described in Application Example 1, and the oil abrasive used is the oil abrasive provided in Example 1. The difference is that in the acid pickling process, a single nitric acid solution with a mass concentration of 10% is used as the pickling solution.

[0289] Comparative Example 4-3

[0290] This comparative example provides an acid pickling process. This comparative example is the same as the acid pickling process described in Application Example 1, and the oil abrasive used is the oil abrasive provided in Example 1. The difference is that in the acid pickling process, the pickling solution is a mixed aqueous solution of hydrochloric acid and nitric acid. Based on the total mass of the pickling solution, it contains 7% hydrochloric acid and 4.0% nitric acid by mass percentage, with the remainder being water.

[0291] Comparative Example 4-4

[0292] This comparative example provides an acid pickling process. This comparative example is the same as the acid pickling process described in Application Example 1, and the oil abrasive used is the oil abrasive provided in Example 1. The difference is that in the acid pickling process, the pickling solution is a mixed aqueous solution of hydrochloric acid and nitric acid. Based on the total mass of the pickling solution, it contains 18% hydrochloric acid and 0.2% nitric acid by mass percentage, with the remainder being water.

[0293] Comparative Example 4-5

[0294] This comparative example provides an acid pickling process. This comparative example is the same as the acid pickling process described in Application Example 1, and the oil abrasive used is the oil abrasive provided in Example 1. The difference is that in the acid pickling process, the pickling solution is a mixed aqueous solution of hydrochloric acid and nitric acid. Based on the total mass of the pickling solution, it contains 30% hydrochloric acid and 10.0% nitric acid by mass percentage, with the balance being water; the mass ratio of hydrochloric acid to nitric acid is 3:1.

[0295] Comparative Examples 4-6

[0296] This comparative example provides an acid pickling process. This comparative example is the same as the acid pickling process described in Application Example 1, and the oil abrasive used is the oil abrasive provided in Example 1. The difference is that in the acid pickling process, the pickling solution is a mixed aqueous solution of hydrochloric acid, nitric acid and hydrofluoric acid. Based on the total mass of the pickling solution, it contains 12% hydrochloric acid, 8% nitric acid and 2% hydrofluoric acid by mass percentage, with the balance being water.

[0297] Comparative Examples 4-7

[0298] This comparative example provides an acid pickling process. This comparative example is the same as the acid pickling process described in Application Example 1, and the oil abrasive used is the oil abrasive provided in Example 1. The difference is that in the acid pickling process, the pickling solution is a mixed aqueous solution of sulfuric acid and nitric acid. Based on the total mass of the pickling solution, it contains 18% sulfuric acid and 6% nitric acid by mass percentage, with the remainder being water.

[0299] Comparative Examples 4-8

[0300] This comparative example provides an acid pickling process. This comparative example is the same as the acid pickling process described in Application Example 1, and the oil abrasive used is the oil abrasive provided in Example 1. The difference is that in the acid pickling process, a pickling solution of hydrofluoric acid and nitric acid is used. The mass concentration of hydrofluoric acid in the pickling solution is 10%, the mass concentration of nitric acid is 15%, and the remainder is water.

[0301] Comparative Examples 4-9

[0302] This comparative example provides an acid pickling process. This comparative example is the same as the acid pickling process described in Application Example 1, and the oil abrasive used is the oil abrasive provided in Example 1. The difference is that in the acid pickling process, a pickling solution of hydrofluoric acid and nitric acid is used. The mass concentration of hydrofluoric acid in the pickling solution is 2%, the mass concentration of nitric acid is 25%, and the remainder is water.

[0303] Comparative Examples 4-10

[0304] This comparative example provides an acid pickling process. The acid pickling process in this comparative example is the same as that in Application Example 1, and the oil abrasive used is the oil abrasive provided in Example 1. The difference is that in the acid pickling process, an acid pickling solution containing sulfuric acid, nitric acid and hydrofluoric acid is used; in the acid pickling solution, the mass concentration of sulfuric acid is 50%, the mass concentration of nitric acid is 10%, the mass concentration of hydrofluoric acid is 2%, and the remainder is water.

[0305] Comparative Example 4-11

[0306] This comparative example provides an acid pickling process. This comparative example is the same as the acid pickling process described in Application Example 1, and the oil abrasive used is the oil abrasive provided in Example 1. The difference is that, in the acid pickling process, based on the mass percentage of each component in the acid pickling solution, the acid pickling solution contains glycerol: 10%, hydrochloric acid: 10%, ferric chloride: 40%, copper chloride: 5%, and the remainder is water.

[0307] Comparative Example 4-12

[0308] This comparative example provides an acid pickling process. This comparative example is the same as the acid pickling process described in Application Example 1, and the oil abrasive used is the oil abrasive provided in Example 1. The difference is that in the acid pickling process, the pickling solution is a mixed aqueous solution of nitric acid and fluorosilicic acid. Based on the total mass of the pickling solution, it contains 12% nitric acid and 3% fluorosilicic acid by mass percentage, with the remainder being water.

[0309] Comparative Example 4-13

[0310] This comparative example provides an acid pickling process. This comparative example is the same as the acid pickling process described in Application Example 1, and the oil abrasive used is the oil abrasive provided in Example 1. The difference is that the acid pickling solution is a mixed aqueous solution of hydrochloric acid and ammonium bifluoride. Based on the total mass of the acid pickling solution, the acid pickling solution contains 10% hydrochloric acid and 5% ammonium bifluoride by mass percentage, with the remainder being water.

[0311] Comparative Example 4-14

[0312] This comparative example provides an acid pickling process. This comparative example is the same as the acid pickling process described in Application Example 1, and the oil abrasive used is the oil abrasive provided in Example 1. The difference is that the acid pickling solution is a mixed aqueous solution of hydrochloric acid and hydrogen peroxide. Based on the total mass of the acid pickling solution, the acid pickling solution contains 12% hydrochloric acid and 5% hydrogen peroxide by mass percentage, with the remainder being water.

[0313] Comparative Examples 4-15

[0314] This comparative example provides an acid pickling process. This comparative example is the same as the acid pickling process described in Application Example 1, and the oil abrasive used is the oil abrasive provided in Example 1. The difference is that the pickling solution is a mixed aqueous solution of nitric acid and citric acid. Based on the total mass of the pickling solution, the pickling solution contains 8% nitric acid and 3% citric acid by mass percentage, with the remainder being water.

[0315] Comparative Example 5

[0316] This comparative example provides an acid pickling process. This comparative example is the same as the acid pickling process described in Application Example 1, and the oil abrasive used is the oil abrasive provided in Example 1. The difference is that the passivation and passivation solution cleaning steps are omitted in the post-treatment, and drying is performed directly after water washing.

[0317] Comparative Example 6

[0318] This comparative example provides an acid pickling process, which is the same as the acid pickling process described in Application Example 1, and uses the same oil abrasive as provided in Example 1. The difference is that in the oil abrasive treatment, a rigid metal-based grinding wheel is used, specifically: cast iron substrate + electroplated diamond abrasive, 1000 mesh. Other parameters such as oil abrasive pressure and grinding speed are consistent with Application Example 1.

[0319] In addition, from Figure 4 It can be seen that the ultra-thin Invar alloy sheet obtained by the pickling process provided in the embodiments of the present invention has good surface quality and flat shape.

[0320] Table 3 Test results of the examples and comparative examples (Group 3)

[0321]

[0322]

[0323]

[0324] pass Figure 5 and Figure 6 In contrast, the pickling process provided in this embodiment of the invention results in significantly lower lattice stress.

[0325] from Figure 7 and Figure 8 It can be seen that the pickling process provided in the embodiments of the present invention ensures the structural integrity of the ultra-thin Invar alloy sheet.

[0326] from Figures 9-10 It can be seen that, compared with the existing pickling process, the pickling process provided by the embodiments of the present invention results in a better surface quality of the board.

[0327] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention.

Claims

1. An oil abrasive suitable for ultra-thin Invar alloy sheets, characterized in that, The oil-refining agent comprises mineral oil and extreme pressure agent, wherein the mass ratio of mineral oil to extreme pressure agent is (8-12):

1.

2. The oil-refining agent according to claim 1, characterized in that, The mineral oil is selected from one or more of naphthenic mineral oil, intermediate-based mineral oil, paraffinic mineral oil, and light white oil; and / or, The extreme pressure agent is selected from one or more of isobutylene sulfide, dibenzyl disulfide, phosphate ester amine salt, and borate ester.

3. The oil-refining agent according to claim 1, characterized in that, The oil abrasive is suitable for ultra-thin Invar alloy sheets with a thickness of ≤0.3mm.

4. A pre-treatment method for pickling of ultra-thin Invar alloy sheets, characterized in that, Includes the following steps: Surface pretreatment: Clean the ultra-thin Invar alloy sheet with a degreasing agent; Oil polishing: The surface of the pretreated ultrathin Invar alloy sheet is polished using the oil polishing compound as described in any one of claims 1 to 3; Rinsing after oil grinding: Use deionized water to rinse and remove residues after oil grinding.

5. The pretreatment method for pickling according to claim 4, characterized in that, In the surface pretreatment, the degreasing agent comprises sodium hydroxide, sodium carbonate, and a nonionic surfactant, wherein the mass ratio of sodium hydroxide, sodium carbonate, and nonionic surfactant is (4-6):(2-4):(1-3); and / or, The nonionic surfactant is selected from one or more of fatty alcohol polyoxyethylene ethers, polyoxyethylene castor oil, alkyl glycosides, and alkylphenol polyoxyethylene ethers; and / or, The working mass concentration of the degreasing agent is 8%-15%.

6. The pretreatment method for pickling according to claim 4, characterized in that, In the surface pretreatment, the temperature of the degreasing agent used is 40-55℃, and the surface pretreatment time is 8-10 minutes.

7. The pretreatment method for pickling according to claim 4, characterized in that, The oil milling process uses a silicon carbide milling head with a particle size of 800-1200 mesh.

8. The pretreatment method for pickling according to claim 4, characterized in that, The process parameters for the oil milling treatment include: an oil milling pressure of 0.1-0.3 MPa; and / or, The grinding speed is 1-3 m / min; and / or, The polishing process is repeated 1-2 times; and / or, During the oil milling process, the oil milling agent is replenished with a spray rate of 5-10 L / h.

9. The pretreatment method for pickling according to claim 4, characterized in that, The post-oil mill rinsing is performed using deionized water at a pressure of 0.6-0.9 MPa; and / or, The rinsing time is 2-4 minutes; and / or, The flushing water flow velocity is 1.0-1.5 m / s; and / or, The post-oil grinding rinsing process uses symmetrical multi-hole nozzles to rinse the surface of the Invar alloy sheet after oil grinding.

10. A pickling process suitable for ultra-thin Invar alloy sheets, characterized in that, Includes the following steps: Pre-pickling treatment: The ultra-thin Invar alloy sheet is treated using the pre-pickling treatment method described in any one of claims 4-9; Pickling treatment: The ultra-thin Invar alloy sheet after pickling pretreatment is immersed in a pickling solution for pickling, wherein the pickling solution is a mixed aqueous solution of hydrochloric acid and nitric acid.

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