A method for preparing aluminum and aluminum alloy plates to eliminate residual stress

Abstract

The application relates to a preparation method for eliminating residual stress of aluminum and aluminum alloy plates, which comprises the following steps: performing rolling treatment on the plates so that the deformation rate of the plates is 1.0%-5.0%; spraying rolling oil on the plates during the rolling process to form an oil film with a thickness of 0.25mm-0.30mm on the surface of the plates; and making the deformation rate of the plates be 1.0%-5.0%. The stress state of the plates in the processing process is changed by rolling to eliminate and balance the internal residual stress of the plates. The flowability of the metal on the processing surface of the plates is changed by changing the viscosity of the surface lubricating oil in the processing process of the plates to balance the internal stress.

Description

Technical Field

[0001] This invention relates to the field of sheet metal processing, and more particularly to a method for preparing aluminum and aluminum alloy sheets to eliminate residual stress. Background Technology

[0002] During the processing of aluminum and aluminum alloy sheets, some internal stress is generated and remains within the metal, forming residual stress. This residual stress varies in magnitude across different directions, causing an imbalance in stress levels throughout the sheet. Consequently, quality defects such as sawing deformation and processing deformation occur during subsequent processing. Traditional methods for eliminating residual stress, such as multi-roll straightening and pre-stretching, are not ideal. Summary of the Invention

[0003] (a) Technical problems to be solved

[0004] This invention provides a preparation method for eliminating residual stress in aluminum and aluminum alloy sheets, aiming to solve the technical problem that the elimination of residual stress in aluminum and aluminum alloy sheets is not ideal in the prior art.

[0005] (II) Technical Solution

[0006] To address the above problems, the present invention provides a method for eliminating residual stress in aluminum and aluminum alloy sheets, the method comprising:

[0007] The sheet metal is rolled to achieve a deformation rate of 1.0%-5.0%. During the rolling process, rolling oil is sprayed onto the sheet metal to form an oil film with a thickness of 0.25mm-0.30mm on the surface of the sheet metal, thereby achieving a deformation rate of 1.0%-5.0%.

[0008] Preferably, the rolling process of the sheet metal includes: rolling the sheet metal three times, and each time rolling the sheet metal, spraying rolling oil onto the sheet metal to form an oil film with a thickness of 0.25mm-0.30mm on the surface of the sheet metal.

[0009] Preferably, the three-stage rolling process of the sheet metal specifically involves:

[0010] The sheet metal is subjected to a first rolling process to achieve a deformation rate of 0.4%-2%.

[0011] The sheet metal is subjected to a second rolling process to reduce the deformation rate to 0.4%-2%.

[0012] The sheet metal is subjected to a third rolling process to reduce the deformation rate to 0.2%-1%.

[0013] Preferably, the thickness of the sheet before rolling is 8mm-350mm, and the convexity is no greater than 0.02mm.

[0014] Preferably, the rolling oil includes: mineral oil, natural grease, synthetic grease, extreme pressure additives, and antioxidants.

[0015] Preferably, in the rolling oil:

[0016] The mineral oil comprises 81.74%-84.81% by mass, the natural lipids comprise 10%-12% by mass, the synthetic lipids comprise 5%-6% by mass, the extreme pressure additives comprise 0.04%-0.06% by mass, and the antioxidants comprise 0.15%-0.2% by mass.

[0017] Preferably, the hardness of the hydraulic roller used to roll the sheet metal is 65-75 HRC.

[0018] Preferably, the plate is further subjected to quenching before rolling.

[0019] (III) Beneficial Effects

[0020] This invention eliminates residual stress by adjusting the deformation rate of the sheet metal by 1.0%-5.0%, and changes the stress state of the sheet metal during processing by rolling. Compared with the traditional multi-roll straightening and pre-stretching methods, it changes the stress from uniaxial tensile stress + biaxial compressive stress to uniaxial compressive stress + biaxial tensile stress to eliminate and balance the residual stress inside the sheet metal. The invention also changes the viscosity of the surface lubricating oil during the sheet metal processing to change the fluidity of the metal on the processed surface, thereby balancing the internal stress. Attached Figure Description

[0021] Figure 1 This is a flowchart of the preparation method for eliminating residual stress in aluminum and aluminum alloy plates according to the present invention. Detailed Implementation

[0022] To better explain and facilitate understanding of the present invention, the present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0023] It should be noted that all directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present invention are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indication will also change accordingly.

[0024] Furthermore, in this invention, descriptions involving "first," "second," etc., are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0025] In this invention, unless otherwise explicitly specified and limited, the terms "connection," "fixed," etc., should be interpreted broadly. For example, "fixed" can mean a fixed connection, a detachable connection, or an integral part; it can mean a mechanical connection or an electrical connection; it can mean a direct connection or an indirect connection through an intermediate medium; it can mean the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0026] This invention provides a method for preparing aluminum and aluminum alloy sheets to eliminate residual stress. The method includes:

[0027] S1, Rolling the sheet metal to achieve a deformation rate of 1.0%-5.0%; During the rolling process, rolling oil is sprayed onto the sheet metal to form an oil film with a thickness of 0.25mm-0.30mm on the surface of the sheet metal; This results in a deformation rate of 1.0%-5.0%.

[0028] Residual stress is eliminated by adjusting the deformation rate of the sheet metal to 1.0%-5.0%, where 1.0%-5.0% refers to the deformation rate in the thickness direction. The rolling process alters the stress state of the sheet metal during processing. Compared to traditional multi-roll straightening and pre-stretching methods, it changes from uniaxial tensile stress + biaxial compressive stress to uniaxial compressive stress + biaxial tensile stress, thereby eliminating and balancing the internal residual stress of the sheet metal. Furthermore, the viscosity of the surface lubricant used during processing is altered to change the fluidity of the metal on the processed surface, achieving the same goal of balancing internal stress.

[0029] Furthermore, the rolling process for the sheet metal includes three rolling processes. During each rolling process, rolling oil is sprayed onto the sheet metal to form an oil film with a thickness of 0.25mm-0.30mm on the surface. Multiple rolling processes can better eliminate internal stress in the sheet metal and achieve the goal of balancing residual stress.

[0030] In a preferred embodiment, the sheet metal undergoes three rolling processes: a first rolling process to achieve a deformation rate of 0.4%-2%; a second rolling process to achieve a deformation rate of 0.4%-2%; and a third rolling process to achieve a deformation rate of 0.2%-1%. The sheet metal thickness before rolling is 8mm-350mm, and the convexity is no greater than 0.02mm. The hardness of the hydraulic rollers used for rolling the sheet metal is 65-75HRC. The convexity difference between the same sheet (center convexity) is no greater than 0.02mm, and the difference between the same edges is less than 0.05mm. The misalignment difference between the upper and lower hydraulic rollers is 0.5mm. The convexity of the hydraulic rollers is 0.15-0.20mm, the surface roughness is 0.4-0.8um, and the misalignment is 3-5mm.

[0031] Different processing deformation amounts are designed according to the thickness of different specifications of the plates, and the processing deformation rate is controlled between 1.0-5.0%; the flatness of the plates is controlled as follows: width direction ≤1.0mm, length direction ≤1.0mm, diagonal direction ≤1.5mm.

[0032] Furthermore, rolling oils include: mineral oil, natural greases, synthetic greases, extreme pressure additives, and antioxidants. In rolling oils: mineral oil accounts for 81.74%-84.81% by mass, natural greases account for 10%-12% by mass, synthetic greases account for 5%-6% by mass, extreme pressure additives account for 0.04%-0.06% by mass, and antioxidants account for 0.15%-0.2% by mass.

[0033] Finally, before rolling the sheet metal, the process also includes: S0, quenching the sheet metal.

[0034] It should be understood that the above description of specific embodiments of the present invention is only for illustrating the technical approach and features of the present invention, and is intended to enable those skilled in the art to understand the content of the present invention and implement it accordingly. However, the present invention is not limited to the specific embodiments described above. All changes or modifications made within the scope of the claims of the present invention should be covered within the protection scope of the present invention.

Claims

1. A method for preparing aluminum and aluminum alloy sheets to eliminate residual stress, characterized in that, The preparation method for eliminating residual stress in aluminum and aluminum alloy plates includes: The sheet metal is rolled to achieve a deformation rate of 1.0%-5.0%. During the rolling process, rolling oil is sprayed onto the sheet metal to form an oil film with a thickness of 0.25mm-0.30mm on the surface, resulting in a deformation rate of 1.0%-5.0%. The rolling process of the sheet metal includes: rolling the sheet metal three times, and each time rolling the sheet metal is rolled, rolling oil is sprayed onto the sheet metal to form an oil film with a thickness of 0.25mm-0.30mm on the surface of the sheet metal. The three-stage rolling process of the sheet metal specifically involves: The sheet metal undergoes a first rolling process to achieve a deformation rate of 0.4%-2%. The sheet metal undergoes a second rolling process to reduce its deformation rate to 0.4%-2%. The sheet metal undergoes a third rolling process to reduce its deformation rate to 0.2%-1%. The rolling oil includes: mineral oil, natural grease, synthetic grease, extreme pressure additives, and antioxidants; In the rolling oil: The mineral oil accounts for 81.74%-84.81% of the total mass, the natural lipids account for 10%-12% of the total mass, the synthetic lipids account for 5%-6% of the total mass, the extreme pressure additives account for 0.04%-0.06% of the total mass, and the antioxidants account for 0.15%-0.2% of the total mass.

2. The preparation method for eliminating residual stress in aluminum and aluminum alloy plates as described in claim 1, characterized in that, The thickness of the sheet metal before rolling is 8mm-350mm, and the convexity value is no greater than 0.02mm.

3. The preparation method for eliminating residual stress in aluminum and aluminum alloy plates as described in claim 1, characterized in that, The hardness of the hydraulic rollers used to roll the sheet metal is 65-75 HRC.

4. The preparation method for eliminating residual stress in aluminum and aluminum alloy plates as described in claim 1, characterized in that, The process of rolling the sheet metal also includes quenching it.

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