Low-expansion alloy 4J36 precision foil and its high-precision surface control method

Abstract

The present invention belongs to the technical field of stainless steel surface treatment, and particularly relates to a low-expansion alloy 4J36 precision foil and a control method for its high-precision surface. In the control method for the high-precision surface of the low-expansion alloy 4J36 precision foil of the present invention, during the finished product rolling process, working rolls with a roughness of Ra 0.4 - 0.5 μm are used in the first five passes, a textured roll with a roughness of Ra 0.3 - 0.4 μm is used in the penultimate pass, and a polished roll with a roughness of Ra ≤ 0.08 μm is used in the finished product pass. The present invention realizes the high-precision surface control of the low-expansion alloy 4J36 precision foil with a thickness of less than 0.05 mm, meeting the precision etching processing requirements of the OLED display screen industry.

Description

Technical Field

[0001] The present invention belongs to the technical field of stainless steel surface treatment, and particularly relates to a low-expansion alloy 4J36 precision foil and a control method for its high-precision surface. Background Art

[0002] Near the magnetic temperature (i.e., Curie point), the thermal expansion coefficient of the low-expansion alloy significantly decreases, showing the so-called abnormal thermal expansion phenomenon. Thus, within a wide temperature range near room temperature, a very small or even nearly zero expansion coefficient can be obtained.

[0003] The 4J36 low-expansion alloy is also called Invar alloy. The Curie point of the alloy is about 230°C. Below this temperature, the alloy is ferromagnetic and has a very low expansion coefficient. Above this temperature, the alloy is non-magnetic and the expansion coefficient increases. This alloy is mainly used to manufacture components with approximately constant dimensions within the temperature change range, and is widely used in the radio industry, precision instruments, meters, and other industries. The 4J36 precision foil of the low-expansion alloy is mainly applied to the production of OLED display screens and semiconductor packaging materials. At the same time, it is the basic material of the key template FMM in the production line, and also includes being used as structural components in aerospace remote sensors, precision lasers, optical measurement systems, and waveguides, the support system of the huge lenses in microscopes and astronomical telescopes, and various scientific instruments that need to install lenses.

[0004] Currently, there is no report on the domestic production of 0.05mm low-expansion alloy 4J36 precision foil products. Checking the international market for low-expansion alloy 4J36 precision foil, Japanese enterprises can produce 4J36 foil with a thickness of 0.05mm and below, and the thinnest is produced to 0.03mm. All domestic corresponding products rely on imports, and the preparation process of related products is blank in China. Summary of the Invention

[0005] The purpose of the present invention is to provide a low-expansion alloy 4J36 precision foil and a control method for its high-precision surface in view of the defects of the prior art.

[0006] Specifically, for the control method of the high-precision surface of the low-expansion alloy 4J36 precision foil of the present invention, during the finished rolling process, a work roll with a roughness of Ra 0.4 - 0.5um is used in the first five passes, a textured roll with a roughness of Ra 0.3 - 0.4um is used in the second-to-last pass, and a polished roll with a roughness of Ra ≤ 0.08um is used in the finished pass.

[0007] For the above control method of the high-precision surface of the low-expansion alloy 4J36 precision foil, during the finished rolling process, the total rolling reduction ≥ 75%, the number of initial rolling passes is not less than 5 passes, the rolling force is not higher than 500KN, and the rolling speed is not higher than 120m / min.

[0008] In the above method for controlling the high-precision surface of the low-expansion alloy 4J36 precision foil, during the finished rolling process, the second intermediate roll uses a free roll with a diameter of 30 - 50 μm and a driving roll with a diameter of 0 - 10 μm, and the diameter difference of the same roll ≤ 10 μm.

[0009] In the above method for controlling the high-precision surface of the low-expansion alloy 4J36 precision foil, during the finished rolling process, the taper length of the first intermediate roll is selected according to the width of the incoming material, and the diameter difference of the same roll ≤ 5 μm.

[0010] In the above method for controlling the high-precision surface of the low-expansion alloy 4J36 precision foil, during the rough rolling process, the total rough rolling deformation ≥ 60%, the number of rough rolling passes is not less than 5 passes, the rolling force is not higher than 600 KN, and the rolling speed is not higher than 300 m / min.

[0011] In the above method for controlling the high-precision surface of the low-expansion alloy 4J36 precision foil, the diameter of the polishing roll is 25 - 28 mm, and the diameter difference of the same roll < 3 mm.

[0012] In the above method for controlling the high-precision surface of the low-expansion alloy 4J36 precision foil, the preparation method of the textured roll includes: (1) grinding a D2 roll with a diameter of 28 - 32 mm using a 240# grinding wheel; (2) performing a polishing treatment after the roll grinding is completed to make the surface roughness Ra of the roll less than 0.1 μm; (3) performing a laser texturing treatment on the polished roll to make the roughness Ra reach 0.3 - 0.4 μm.

[0013] On the other hand, the present invention also provides a low-expansion alloy 4J36 precision foil, which is controlled by the above method for controlling the high-precision surface during the preparation process.

[0014] In the above low-expansion alloy 4J36 precision foil, the thickness of the low-expansion alloy 4J36 precision foil ≤ 0.05 mm.

[0015] In the above low-expansion alloy 4J36 precision foil, the thickness of the low-expansion alloy 4J36 precision foil ≤ 0.03 mm.

[0016] The technical solution of the present invention has the following beneficial effects:

[0017] The method for controlling the high-precision surface of the low-expansion alloy 4J36 precision foil of the present invention includes innovative designs such as the control of the textured roll and the polishing roll, the rolling technology of ultra-thin precision foil, the configuration and usage method of the roll system in the finished rolling process, etc., realizing the high-precision surface control of the low-expansion alloy 4J36 precision foil with a thickness of less than 0.05 mm, and meeting the precision etching processing requirements of the OLED display screen industry. Description of the Drawings

[0018] Various other advantages and benefits will become clear to those of ordinary skill in the art by reading the following detailed description of the preferred embodiments. The drawings are only for the purpose of showing the preferred embodiments and are not considered to be a limitation of the present invention.

[0019] Figure 1 Photograph of the surface texture of the low-expansion alloy 4J36 precision foil obtained by the method according to the present invention;

[0020] Figure 2 Photograph of the surface texture of the low-expansion alloy 4J36 precision foil obtained during the finished rolling process using a conventional roll. Detailed Embodiments

[0021] In order to fully understand the purpose, features and effects of the present invention, the present invention will be described in detail through the following specific embodiments. Except for the following content, the process methods of the present invention all adopt conventional methods or devices in the art. Unless otherwise specified, the following terms have the meanings commonly understood by those skilled in the art.

[0022] As used herein, the terms "the", "said", "a" and "an" do not denote a limitation of quantity, but rather denote the presence of at least one of the objects mentioned. The terms "preferred", "more preferred", etc. refer to embodiments of the present invention that may provide certain beneficial effects in certain cases. However, in the same or other cases, other embodiments may also be preferred. In addition, the recitation of one or more embodiments does not imply that other embodiments are not available, nor is it intended to exclude other embodiments from the scope of the present invention.

[0023] When a numerical range is disclosed herein, the above range is considered continuous and includes the minimum and maximum values of the range, as well as each value therebetween. Further, when the range refers to integers, it includes each integer between the minimum and maximum values of the range. In addition, when multiple ranges are provided to describe features or characteristics, the ranges may be combined. In other words, unless otherwise specified, all ranges disclosed herein should be understood to include any and all sub-ranges subsumed therein.

[0024] The object of the present invention is to provide a high-precision surface control method for a low-expansion alloy 4J36 precision foil with a thickness ≤ 0.05 mm. The so-called high-precision surface herein means ensuring no obvious rolling texture on the surface of the foil while ensuring a low roughness (about Ra 0.1 μm). To achieve this object, the inventors of the present application have developed a multi-pass composite rolling technology for the low-expansion alloy 4J36 precision foil using various types of rolls through creative labor.

[0025] Specifically, for the method of controlling the high-precision surface of the low-expansion alloy 4J36 precision foil of the present invention, during the finished product rolling process, work rolls with a roughness of Ra 0.4 - 0.5 μm are used in the first five passes, a textured roll with a roughness of Ra 0.3 - 0.4 μm is used in the second-to-last pass, and a polished roll with a roughness of Ra ≤ 0.08 μm is used in the finished product pass.

[0026] By using work rolls of three roughness types during the finished product rolling process, the present invention can effectively control the roughness of the low-expansion alloy 4J36 precision foil during the rolling process. In particular, by controlling the roughness of the textured roll between Ra 0.3 - 0.4, the high-precision surface of the foil meets the requirements of industrial applications.

[0027] Preferably, the method for preparing the textured roll with a roughness of Ra 0.3 - 0.4 μm is as follows:

[0028] (1) Grind a D2 roll with a diameter of 28 - 32 mm using a 240# grinding wheel. The quality requirement is the surface requirement of an electroplated roll, that is: there should be no detectable sand drop marks, spiral lines, vibration marks, rack marks, etc. by touch. The diameter tolerance is less than 3 μm, and the roughness Ra is less than 0.12 μm.

[0029] (2) After the roll grinding is completed, polish the roll so that the roughness Ra of the roll is less than 0.1 μm and there should be no scratches on the surface.

[0030] (3) Perform laser texturing on the polished roll so that the roughness Ra reaches 0.3 - 0.4 μm. The surface texture is uniform and disordered, and there should be no surface quality defects such as vibration marks and color differences.

[0031] Optionally, the roughness of the textured roll can be adjusted according to different customer requirements.

[0032] Preferably, the polished roll is selected from work rolls with a diameter range of 25 - 28 mm. The requirement for the diameter difference between the two sides of the same roll is less than 3 μm, and the roughness Ra is within 0.08 μm. Thus, the effect that there are no rolling lines after magnifying 120 times and the roughness is within Ra 0.1 can be achieved for the final product requirements.

[0033] More preferably, the roughness of the polished roll can be adjusted according to different customer requirements.

[0034] Among them, the "diameter difference of the same roll" refers to the diameter difference between the two sides of a roll. During the roll grinding process, it is impossible to ensure that the diameter of each point on the roll is exactly the same, so it is necessary to measure the diameter difference of the same roll to represent the accuracy of the roll.

[0035] Optionally, the preparation methods of the working roll with a roughness of Ra 0.4 - 0.5 μm and the polishing roll with a roughness of Ra ≤ 0.08 μm can both be carried out according to the prior art, and the present invention will not elaborate on this in detail.

[0036] In some preferred embodiments, the ultra-thin precision foil rolling technology is adopted in the rolling process of the low-expansion alloy 4J36 precision foil of the present invention, including: two rolling processes of rough rolling and finish rolling.

[0037] Among them, in the rough rolling process, the total rough rolling deformation is ≥ 60%, the number of rough rolling passes is not less than 5 passes, the rolling force is not higher than 600 KN, and the rolling speed is not higher than 300 m / min, so as to ensure efficient production in the intermediate rolling process and controllable surface quality.

[0038] Among them, in the finish rolling process, the total rolling deformation is ≥ 75%, the number of finish rolling passes is not less than 5 passes, the rolling force is not higher than 500 KN, and the rolling speed is not higher than 120 m / min. Thereby, the shape of the finished product can be controlled.

[0039] Among them, both the rough rolling and the finish rolling are carried out in a reversible 20-high four-column rolling mill.

[0040] Further preferably, the roll system configuration and usage method of the low-expansion alloy 4J36 precision foil of the present invention in the finish rolling process are as follows:

[0041] (1) Use of the second intermediate roll: Since the deformation in the finish rolling process is ≥ 75%, in order to ensure controllable shape, rolling force and no strip breakage, the second intermediate roll uses a free roll of 30 - 50 μm and a drive roll of 0 - 10 μm, and the diameter difference within the same roll is within 10 μm;

[0042] Among them, the "free roll of 30 - 50 μm" and the "free roll of 0 - 10 μm" mean that the cross-sectional diameter at the middle position of the entire roll is 30 - 50 μm and 0 - 10 μm larger than the cross-sectional diameters at both ends respectively.

[0043] (2) Use of the first intermediate roll: According to the width of the incoming material, select the first intermediate roll with a corresponding taper length, and the diameter difference within the same roll is within 5 μm;

[0044] Optionally, in one embodiment, the incoming material is 600 mm wide, and the specifications of the selected first intermediate roll are: taper length 130 mm, taper height 210 μm.

[0045] (3) Use of the working roll: All the first 5 passes use a working roll with Ra 0.4 - 0.5 μm, the second last pass uses a textured roll with 0.3 - 0.4 μm, and the finish pass uses a polishing roll with Ra within 0.08 μm.

[0046] The control method for the high-precision surface of the low-expansion alloy 4J36 precision foil divides the high-precision surface control process of the low-expansion alloy 4J36 precision foil into: the control of the textured roll and the polishing roll, the rolling technology of the ultra-thin precision foil, and the configuration and use of the roll system in the finishing rolling process. Through a deformation amount of more than 70%, in terms of strict roll use and precision control, precision foil rolling technology, roll system configuration, etc., the high-precision surface control of the low-expansion alloy 4J36 precision foil with low roughness and no texture is realized, meeting the use requirements of the industry's precision etching processing.

[0047] On the other hand, the present invention also provides a low-expansion alloy 4J36 precision foil, which is controlled by the above-mentioned high-precision surface control method during the preparation process.

[0048] Among them, the thickness of the low-expansion alloy 4J36 precision foil ≤ 0.05 mm (preferably ≤ 0.03 mm).

[0049] When viewing the surface of the low-expansion alloy 4J36 precision foil of the present invention under the condition of 100 times magnification, it is found that its surface roughness is low and there is no texture. Based on the rolling process of the ultra-thin stainless steel precision foil, it meets the organizational structure size requirements of the industry's precision etching processing, filling the domestic blank in the special alloy foil industry.

[0050] Embodiment

[0051] The present invention will be further described below by way of examples, but the present invention is not limited to the scope of the described examples. The experimental methods without specific conditions in the following examples are carried out according to conventional methods and conditions.

[0052] Example 1

[0053] In the primary rolling process, the thickness of the strip raw material used is 0.25 mm, the primary rolling target thickness is 0.10 mm, and the number of rolling passes is 6 passes. The process parameters of each rolling pass are as follows:

[0054]

[0055]

[0056] The target thickness of the finishing rolling process is 0.025 mm, and 7 passes of rolling are used. The process parameters of each rolling pass are as follows:

[0057]

[0058] During the finishing rolling process, the working roll use process is as follows: for the first 5 passes, all use working rolls with Ra 0.4 - 0.5 um, the second-to-last pass uses a textured roll with 0.3 - 0.4 um, and the finishing pass uses a polishing roll with Ra within 0.08 um.

[0059] During the finished product rolling process, the incoming material width tested was 580 mm, the length of the first intermediate cone used was 130 * 210; the difference in roll diameters of the same roll was 6 μm, and the difference in roll diameters of the second intermediate roll of the same roll was 8 μm.

[0060] After the finished product rolling process ended, the surface of the low-expansion alloy 4J36 precision foil was inspected under a magnification of 100 times, and it was found that its surface roughness was low and there were no textures (as Figure 1 shown)

[0061] Comparative example

[0062] The main difference in the rolling of the low-expansion alloy 4J36 precision foil with a conventional surface and the low-expansion alloy 4J36 precision foil with a texture-free surface lies in the use of work rolls. For example, for 5 passes of rolling, all the first 4 passes used rough rolls with Ra 0.4, and the finished product used a fine roll with Ra 0.2. After repeated process tests, it was found that its surface roughness was high and there were obvious textures (as Figure 2 shown), which could not meet the usage requirements of precision etching processing in the industry.

[0063] The present invention has been disclosed above in preferred embodiments. However, those skilled in the art should understand that these embodiments are only used to illustrate the present invention and should not be construed as limiting the scope of the present invention. It should be noted that all equivalent changes and substitutions to these embodiments should be regarded as being covered within the scope of the claims of the present invention. Therefore, the protection scope of the present invention should be subject to the scope defined in the claims.

Claims

1. A method for controlling the high-precision surface of a low-expansion alloy 4J36 precision foil, characterized in that, During the blooming rolling process, the total blooming deformation ≥ 60%, the number of blooming passes is not less than 5 passes, the rolling force is not higher than 600 KN, and the rolling speed is not higher than 300 m / min; During the finish rolling process, the total rolling deformation ≥ 75%, the number of blooming passes is not less than 5 passes, the rolling force is not higher than 500 KN, and the rolling speed is not higher than 120 m / min; The work roll with a roughness of Ra 0.4 - 0.5 um is used in the first five passes, the textured roll with a roughness of Ra 0.3 - 0.4 um is used in the second last pass, and the polished roll with a roughness of Ra ≤ 0.08 um is used in the finish pass; The taper length of the first intermediate roll is selected according to the incoming material width, and the diameter difference of the same roll ≤ 5 um; The second intermediate roll adopts a free roll with a cross-sectional diameter at the middle position of the whole roll 30 - 50 um larger than that at both ends and a driving roll with a cross-sectional diameter at the middle position of the whole roll 0 - 10 um larger than that at both ends, and the diameter difference of the same roll ≤ 10 um; Among them, the diameter difference of the same roll refers to the diameter difference between both sides of a roll.

2. The control method for the high-precision surface of the low-expansion alloy 4J36 precision foil according to claim 1, wherein, The diameter of the polished roll is 25 - 28 mm, and the diameter difference of the same roll < 3 mm.

3. The control method for the high-precision surface of the low-expansion alloy 4J36 precision foil according to claim 1, wherein, The preparation method of the textured roll includes: (1) Grinding a D2 roll with a diameter of 28 - 32 mm using a 240# grinding wheel; (2) After the roll grinding is completed, perform a polishing treatment to make the roll roughness Ra less than 0.1 um; (3) Perform a laser texturing treatment on the polished roll to make the roughness Ra reach 0.3 - 0.4 um.

4. A precision foil of low-expansion alloy 4J36, characterized in that, During the preparation process, the control method for the high-precision surface described in any one of claims 1 - 3 is used for control.

5. The low-expansion alloy 4J36 precision foil according to claim 4, characterized in that, The thickness of the low-expansion alloy 4J36 precision foil ≤ 0.05 mm.

6. The low-expansion alloy 4J36 precision foil according to claim 4, wherein, The thickness of the low-expansion alloy 4J36 precision foil ≤ 0.03 mm.

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