Preparation method of high-strength and highly corrosion-resistant Al-Mg-Mn-Zn-Er-Zr alloy thin plate

Abstract

The present invention provides a method for preparing a high-strength and highly corrosion-resistant Al-Mg-Mn-Zn-Er-Zr alloy thin plate, belonging to the fields of pressure processing and heat treatment. By adopting a direct stabilization annealing + cold deformation process, the present invention greatly improves the strength of the material while ensuring the corrosion resistance of the finished plate, and the comprehensive performance of the material is improved. By adopting a stabilization annealing + appropriate amount of cold deformation process, a high-strength and highly corrosion-resistant Al-Mg-Mn-Zn-Er-Zr alloy thin plate is obtained.

Description

Technical Field

[0001] The present invention belongs to the technical field of alloy thin plates, and particularly relates to a preparation method of a high-strength and highly corrosion-resistant Al-Mg-Mn-Zn-Er-Zr alloy thin plate, specifically a pressure processing and heat treatment method of a high-strength and highly corrosion-resistant Al-Mg-Mn-Zn-Er-Zr alloy, and more specifically a pressure rolling and stabilization annealing method of an Al-Mg-Mn-Zn-Er-Zr alloy. Background Art

[0002] The 5xxx alloy is a non-heat-treatable strengthened aluminum alloy with medium strength, excellent corrosion resistance and weldability. Corrosion-resistant marine materials can be obtained through special heat treatment methods, and it is currently the most widely used marine aluminum alloy material. With the rapid development of the global economy, various ship-related industries such as shipping, ocean development, and marine fisheries have flourished. Aluminum ships are developing towards large-scale and lightweight, and there is an urgent need for new aluminum alloy materials with higher strength to improve the stiffness of ships. Based on the 5xxx aluminum alloy with a high Mg content, by compounding and adding trace elements of Zn, Er, and Zr, the comprehensive properties of the material can be improved to a certain extent. For example, the patent "A Rolling and Stabilization Annealing Process of Al-Mg-Mn-Er-Zr Alloy" proposes intermediate annealing at 300 - 350 °C for 2 h for hot-rolled sheets, then cold rolling by 40 - 60%, and finally stabilization annealing at 240 - 280 °C for 1 - 10 h; two heat treatment processes of intermediate annealing and stabilization annealing are required, with high energy consumption, long production cycles, low efficiency of equipment production capacity, and insufficient market competitiveness of products; the properties of the sheets prepared by the patent "A Rolling and Stabilization Annealing Process of Al-Mg-Mn-Er-Zr Alloy" are yield strength of 210 - 235 MPa, tensile strength of 395 - 410 MPa, and elongation of 14 - 19 MPa, and the strength index cannot fully meet the requirements of high-performance marine aluminum alloy sheets. Summary of the Invention

[0003] In view of this, the purpose of the embodiments of the present invention is to provide a preparation method of a high-strength and highly corrosion-resistant Al-Mg-Mn-Zn-Er-Zr alloy thin plate, and the products prepared by the method provided by the present invention have good properties.

[0004] The present invention provides a preparation method of a high-strength and highly corrosion-resistant Al-Mg-Mn-Zn-Er-Zr alloy thin plate, including:

[0005] Heating the ingot and then performing hot rough rolling to obtain hot rough-rolled sheets;

[0006] Performing hot finish rolling on the hot rough-rolled sheets to obtain hot finish-rolled coils;

[0007] The hot-rolled coil is subjected to stabilizing annealing and then cold-rolled to obtain a high-strength and highly corrosion-resistant Al-Mg-Mn-Zn-Er-Zr alloy thin sheet.

[0008] Preferably, the composition of the ingot is Al-5.8Mg-0.7Mn-0.6Zn-0.15Er-0.1Zr.

[0009] Preferably, the heating temperature is 450-520 °C and the holding time is 2-4 h.

[0010] Preferably, the temperature of the hot rough rolling is 400-450 °C.

[0011] Preferably, the pass reduction rate of the hot rough rolling is 5-30%;

[0012] The total reduction rate of the hot rough rolling > 90%.

[0013] Preferably, the thickness of the hot-rolled rough sheet is 20-25 mm.

[0014] Preferably, the temperature of the hot finish rolling is 250-300 °C.

[0015] Preferably, the pass reduction rate of the hot finish rolling is 10-25%;

[0016] The total reduction rate of the hot finish rolling > 70%.

[0017] Preferably, a cold rolling reduction rate is reserved during the hot finishing;

[0018] The reserved cold rolling reduction rate is 15-20%.

[0019] Preferably, the temperature of the stabilizing annealing is 280-290 °C and the holding time is 1-3 h.

[0020] The present invention optimizes the preparation process route and process of the Al-Mg-Mn-Er-Zr alloy sheet, and provides a method for producing a high-strength and highly corrosion-resistant Al-Mg-Mn-Zn-Er-Zr alloy thin sheet. The present invention obtains a high-strength and highly corrosion-resistant Al-Mg-Mn-Zn-Er-Zr alloy thin sheet through a direct stabilizing + cold deformation process. Description of the Drawings

[0021] Figure 1 Yield strength curves of the Al-Mg-Mn-Zn-Er-Zr alloy thin sheets prepared in the examples and comparative examples;

[0022] Figure 2 Tensile strength curves of the Al-Mg-Mn-Zn-Er-Zr alloy thin sheets prepared in the examples and comparative examples;

[0023] Figure 3 Elongation curves of the Al-Mg-Mn-Zn-Er-Zr alloy thin plates prepared in the examples and comparative examples;

[0024] Figure 4 Intergranular corrosion mass loss curves of the Al-Mg-Mn-Zn-Er-Zr alloy thin plates prepared in the examples and comparative examples. Specific implementation manners

[0025] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0026] The present invention provides a preparation method for a high-strength and high-corrosion-resistant Al-Mg-Mn-Zn-Er-Zr alloy thin plate, comprising:

[0027] Heating the ingot and then performing hot rough rolling to obtain a hot-rough-rolled sheet;

[0028] Performing hot finish rolling on the hot-rough-rolled sheet to obtain a hot-finish-rolled coil;

[0029] Performing stabilizing annealing on the hot-finish-rolled coil, and then performing cold rolling to obtain a high-strength and high-corrosion-resistant Al-Mg-Mn-Zn-Er-Zr alloy thin plate.

[0030] In the present invention, the composition of the ingot is preferably Al-5.8Mg-0.7Mn-0.6Zn-0.15Er-0.1Zr; that is: Mg 5.8wt%, Mn 0.7wt%, Zn 0.6wt%, Er 0.15wt%, Zr 0.1wt%, and the balance is Al.

[0031] In the present invention, the heating temperature is preferably 450-520°C, more preferably 460-510°C, still more preferably 470-500°C, and most preferably 480-490°C; the heating holding time is preferably 2-4 h, more preferably 2.5-3.5 h, and most preferably 3 h.

[0032] In the present invention, the hot-rough-rolling temperature is preferably 400-450°C, more preferably 410-440°C, and most preferably 420-430°C; the pass deformation rate of the hot rough rolling is preferably 5-30%, more preferably 10-25%, and most preferably 15-20%; the total deformation rate of the hot rough rolling is preferably >90%.

[0033] In the present invention, the thickness of the hot-rolled rough sheet is preferably 20 - 25 mm, more preferably 21 - 24 mm, and most preferably 22 - 23 mm.

[0034] In the present invention, the hot finish rolling is preferably online hot finish rolling. When performing the hot finish rolling, it is preferable to reserve a cold rolling deformation rate. The reserved cold rolling deformation rate is preferably 15 - 20%, more preferably 16 - 19%, and most preferably 17 - 18%. In the present invention, the temperature of the hot finish rolling is preferably 250 - 300 °C, more preferably 260 - 290 °C, and most preferably 270 - 280 °C; the pass deformation rate of the hot finish rolling is preferably 10 - 25%, more preferably 15 - 20%, and most preferably 16 - 18%; the total deformation rate of the hot finish rolling is preferably > 70%.

[0035] In the present invention, the temperature of the stabilizing annealing is preferably 280 - 290 °C, more preferably 282 - 288 °C, and most preferably 284 - 286 °C; the holding time of the stabilizing annealing is preferably 1 - 3 h, more preferably 1.5 - 2.5 h, and most preferably 2 h.

[0036] In the present invention, it is preferable to perform cold rolling on the coil after stabilizing annealing. The deformation rate of the cold rolling is preferably 15 - 20%, more preferably 16 - 19%, and most preferably 17 - 18%.

[0037] The present invention optimizes the preparation process route and process of the Al-Mg-Mn-Er-Zr alloy sheet, and provides a method for producing high-strength and energy-saving Al-Mg-Mn-Zn-Er-Zr alloy thin sheets. Through the direct stabilization + cold deformation process, the present invention obtains high-strength and highly corrosion-resistant Al-Mg-Mn-Zn-Er-Zr alloy thin sheets.

[0038] Comparative Example 1

[0039] Heat the Al-5.8Mg-0.7Mn-0.6Zn-0.15Er-0.1Zr alloy ingot to 480 °C, hold for 3 h and then perform hot rough rolling. The hot rough rolling temperature is 420 °C, the pass deformation rate is 20%, and the total hot rough rolling deformation rate is 95%. The thickness of the obtained hot-rolled rough sheet is 22 mm.

[0040] Continuously perform online hot finish rolling on the obtained hot-rolled rough sheet to 8.0 mm, reserve a 50% cold rolling deformation rate for cold rolling. The hot finish rolling temperature is 250 °C, the pass deformation rate is 10%, and the total hot finish rolling deformation rate is 64% to obtain a hot-finished coil.

[0041] Anneal the obtained hot-finished coil at 320 °C for 2 h; cold roll the coil after intermediate annealing to 4.0 mm, the cold rolling deformation rate is 50%, and the cold-rolled coil is stabilized and annealed at 270 °C for 4 h to obtain the finished sheet.

[0042] Example 1

[0043] Heat the Al-5.8Mg-0.7Mn-0.6Zn-0.15Er-0.1Zr alloy ingot to 480 °C, hold for 3 h, then perform hot rough rolling. The hot rough rolling temperature is 420 °C, the pass reduction rate is 20%, and the total hot rough rolling reduction rate is 95%. The thickness of the obtained hot-rolled rough plate is 22 mm.

[0044] Continuously hot finish roll the obtained hot-rolled rough plate online to 4.7 mm, reserving 15% cold rolling reduction rate for cold rolling. The hot finish rolling temperature is 250 °C, the pass reduction rate is 10%, and the total hot finish rolling reduction rate is 79%. Obtain a hot-finished rolled coil.

[0045] Stabilize and anneal the obtained hot-finished rolled coil at 290 °C for 2 h; after the coil is stabilized, cold roll it to 4.0 mm, and the cold rolling reduction rate is 15% to obtain a finished plate.

[0046] Example 2

[0047] Heat the Al-5.8Mg-0.7Mn-0.6Zn-0.15Er-0.1Zr alloy ingot to 480 °C, hold for 3 h, then perform hot rough rolling. The hot rough rolling temperature is 420 °C, the pass reduction rate is 20%, and the total hot rough rolling reduction rate is 95%. The thickness of the obtained hot-rolled rough plate is 22 mm.

[0048] Continuously hot finish roll the obtained hot-rolled rough plate online to 4.8 mm, reserving 17% cold rolling reduction rate for cold rolling. The hot finish rolling temperature is 250 °C, the pass reduction rate is 10%, and the total hot finish rolling reduction rate is 78%. Obtain a hot-finished rolled coil.

[0049] Stabilize and anneal the obtained hot-finished rolled coil at 290 °C for 2 h; after the coil is stabilized, cold roll it to 4.0 mm, and the cold rolling reduction rate is 17% to obtain a finished plate.

[0050] Example 3

[0051] Heat the Al-5.8Mg-0.7Mn-0.6Zn-0.15Er-0.1Zr alloy ingot to 480 °C, hold for 3 h, then perform hot rough rolling. The hot rough rolling temperature is 420 °C, the pass reduction rate is 20%, and the total hot rough rolling reduction rate is 95%. The thickness of the obtained hot-rolled rough plate is 22 mm.

[0052] Continuously hot finish roll the obtained hot-rolled rough plate online to 5.0 mm, reserving 20% cold rolling reduction rate for cold rolling. The hot finish rolling temperature is 250 °C, the pass reduction rate is 10%, and the total hot finish rolling reduction rate is 77%. Obtain a hot-finished rolled coil.

[0053] The obtained hot-rolled coil is stabilized and annealed at 290°C for 2 hours; after stabilization of the coil, it is cold-rolled to 4.0 mm, and the cold-rolling deformation rate is 20% to obtain the finished sheet.

[0054] Performance testing

[0055] The finished sheets prepared in the comparative examples and the examples are subjected to performance testing. Tensile property indexes such as yield strength, tensile strength, and elongation are tested according to GB / T 228.1, intergranular corrosion is tested according to ASTM G66, and exfoliation corrosion is tested according to ASTM G67.

[0056] The test results are as follows and Figures 1 to 4 are shown as:

[0057]

[0058] The present invention optimizes the preparation process route and process of Al-Mg-Mn-Er-Zr alloy sheets, and provides a method for producing high-strength and energy-saving Al-Mg-Mn-Zn-Er-Zr alloy thin sheets. Through the direct stabilization + cold deformation process, the present invention obtains high-strength and highly corrosion-resistant Al-Mg-Mn-Zn-Er-Zr alloy thin sheets.

[0059] Although the present invention has been described and illustrated with reference to specific embodiments of the present invention, such description and illustration do not limit the present invention. Those skilled in the art can clearly understand that various changes can be made without departing from the true spirit and scope of the present invention as defined by the appended claims, so as to adapt a specific situation, material, composition of matter, substance, method, or process to the object, spirit, and scope of the present application. All such modifications are intended to be within the scope of the appended claims. Although the methods disclosed herein have been described with reference to specific operations performed in a specific order, it should be understood that these operations can be combined, subdivided, or reordered without departing from the teachings of the present invention to form equivalent methods. Therefore, unless specifically indicated herein, the order and grouping of operations are not limitations of the present application.

Claims

1. A method for preparing a high-strength and highly corrosion-resistant Al-Mg-Mn-Zn-Er-Zr alloy thin plate, comprising: Heat the ingot to 450~520°C, hold for 2~4 h, and then perform hot rough rolling to obtain hot-rolled rough plates. The temperature of the hot rough rolling is 400~450°C, the pass reduction rate of the hot rough rolling is 5~30%, and the total reduction rate of the hot rough rolling > 90%. The composition of the ingot is Al-5.8Mg-0.7Mn-0.6Zn-0.15Er-0.1Zr; Perform hot finish rolling on the hot-rolled rough plates to obtain hot-rolled finished coils. The pass reduction rate of the hot finish rolling is 10~25%, and the total reduction rate of the hot finish rolling > 70%. Leave a cold rolling reduction rate during the hot finish rolling. The reserved cold rolling reduction rate is 15~20%; Perform stress-relief annealing on the hot-rolled finished coils, and then perform cold rolling to obtain high-strength and highly corrosion-resistant Al-Mg-Mn-Zn-Er-Zr alloy sheets. The temperature of the stress-relief annealing is 280~290°C, the holding time is 1~3 h, and the reduction rate of the cold rolling is 15~20%.

2. The method according to claim 1, characterized in that The thickness of the hot-rolled rough plates is 20~25 mm.

3. The method according to claim 1, characterized in that The temperature of the hot finish rolling is 250~300°C.

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