3003 aluminum alloy with high corrosion resistance and cast rolling production process thereof

Abstract

The invention relates to the technical field of metal material production, in particular to a high-corrosion-resistance 3003 aluminum alloy and a cast rolling production process thereof, and the high-corrosion-resistance 3003 aluminum alloy comprises the following components in percentage by mass: 0.87 to 1.96 percent of Mn, 0.11 to 0.83 percent of Fe, 0.17 to 1.13 percent of S i, 0.09 to 1.43 percent of Cu, 0.01 to 0.18 percent of Zn, 0.01 to 0.23 percent of T i and the balance of A and inevitable impurities. The total mass ratio of the added alloy element components is smaller than or equal to 6 wt.%, the content of the alloy elements is low, and the advantage of low cost is achieved; the alloy preparation process utilizes a double-roller casting and rolling technology, has the advantages of short process, high efficiency, low cost and the like, and ensures efficient preparation of the alloy; cooperative regulation and control of alloy components, process and process parameters are achieved by regulating and controlling the double-roller casting and rolling temperature, and the formability and corrosion resistance of the alloy are improved.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of metal material production, in particular to a 3003 aluminum alloy with high corrosion resistance and a cast-rolling production process thereof. BACKGROUND

[0002] The 3003 aluminum alloy is a typical Al-Mn deformed aluminum alloy, and is widely applied to humid or chlorine ion-containing environments such as heat exchange systems, ship components and chemical containers due to its excellent corrosion resistance, good formability and heat conductivity. However, in a harsh marine environment, aluminum alloy components (such as radiators) are prone to corrosion damage. The Cl-ions in the marine environment can erode the protective oxide film on the surface of the aluminum alloy, induce various local corrosion forms, and eventually lead to component failure. With the wide application of aluminum alloys in marine engineering and new energy vehicles, there is an urgent need for large-scale, low-cost and high-performance aluminum alloy components.

[0003] Double-roller continuous casting (TRC) is a near-net shape manufacturing process that directly solidifies molten metal into a shape. This process uniquely integrates the solidification process with hot rolling deformation, utilizing the high cooling rate between the roller gap to achieve rapid solidification, thereby significantly shortening the production process. Compared with the traditional multi-process process (melting, casting, heat treatment and rolling), the TRC process has significant advantages in production efficiency, manufacturing cost, energy saving and process simplification. However, the extremely high cooling rate (usually up to 10 2 -10 3 ℃ / s) in the double-roller continuous casting process causes the solidification process of the alloy to be in a non-equilibrium state, which inevitably leads to the formation of macroscopic and microscopic segregation. The existence of segregation in the aluminum alloy organization adversely affects the corrosion resistance of the alloy, and even significantly reduces the corrosion resistance of the aluminum alloy.

[0004] Currently, the conventional method to eliminate the segregation of double-roller cast aluminum alloy plates is to perform subsequent heat treatment and rolling on the aluminum alloy plates. However, the post-processing of the alloy has multiple technical limitations: on the one hand, the post-processing process increases the production cost, which goes against the original intention of the double-roller casting high efficiency, short process and low cost; on the other hand, the subsequent rolling deformation and heat treatment also cannot completely eliminate the segregation produced in the casting process. The organization of the double-roller cast aluminum alloy depends on the casting process parameters, and the organization has a direct impact on the performance, and the casting temperature has the most significant impact on the characteristics of the solidification organization. The existing method for improving the performance of double-roller cast aluminum alloy plates has a relatively complex processing flow and a cumbersome entire processing step, and therefore the application provides a 3003 aluminum alloy with high corrosion resistance and a cast-rolling production process thereof. SUMMARY

[0005] The present application aims to provide a 3003 aluminum alloy with high corrosion resistance and a cast-rolling production process thereof to solve the problems in the background art.

[0006] To solve the above technical problems, the present application provides the following technical solution: a 3003 aluminum alloy with high corrosion resistance, comprising the following components in terms of mass percentage: Mn: 0.87-1.96%, Fe: 0.11-0.83%, Si: 0.17-1.13%, Cu: 0.09-1.43%, Zn: 0.01-0.18%, Ti: 0.01-0.23%, and the balance being Al and unavoidable impurities.

[0007] According to the above technical solution, the purity of the Mn, Fe, Si, Cu, Zn and Ti element particles is >99.9%;

[0008] A cast-rolling production process of a 3003 aluminum alloy with high corrosion resistance, comprising the following steps:

[0009] S1, raw material configuration: heat and melt the aluminum ingot under argon protection, and after complete melting, accurately adjust the chemical composition and mass percentage ratio of the melt composition as follows: Mn: 0.87-1.96%, Fe: 0.11-0.83%, Si: 0.17-1.13%, Cu: 0.09-1.43%, Zn: 0.01-0.18%, Ti: 0.01-0.23%, and the balance being Al and unavoidable impurities, and after sufficient stirring, carry out refining, degassing and slag removal to obtain an alloy melt;

[0010] S2, plate cast-rolling: the alloy melt obtained in S1 enters a double-roller casting equipment for continuous casting and rolling at a casting and rolling temperature of 660-730℃, thereby obtaining a 3003 aluminum alloy plate;

[0011] S3, gas mist cooling: the 3003 aluminum alloy plate obtained in S2 is cooled through a plurality of gas mist cooling nozzles, and after gas mist cooling, a slab is obtained, high-pressure gas is sprayed to the slab to blow off the cooling water and eliminate water marks on the surface of the slab;

[0012] S4, temperature-controlled coiling: the slab obtained in S3 is coiled at a controlled temperature to obtain a hot coil;

[0013] S5, offline finishing: the hot coil obtained in S4 is finished by using a stretch leveling and flattening process to obtain a finished coil;

[0014] According to the above technical solution, the process parameters of the double-roller casting equipment in S1 are as follows: casting and rolling speed: 700-900 mm / min, and roller gap distance: 4-8 mm;

[0015] According to the technical scheme, the cooling rate of the gas mist cooling in S2 is 90-150℃ / s.

[0016] Compared with the prior art, the application has the following beneficial effects: the mass percentage of the added alloy element composition is ≤6wt.%, the content of the alloy element is low, and the application has a low-cost advantage; the double-roller casting technology is used in the alloy preparation process, and the alloy is prepared efficiently with the advantages of short process, high efficiency, and low cost; the alloy component, process, and process parameter are synergistically controlled by regulating the double-roller casting temperature, and the formability and corrosion resistance of the alloy are improved. Specifically, the application has the following advantages:

[0017] 1) The prior art usually uses subsequent heat treatment and rolling methods to change the internal organizational structure, grain size, orientation, or phase distribution of the alloy to solve a certain technical problem in the alloy preparation process; the application directly regulates the double-roller casting temperature to change the internal organizational structure, grain size, orientation, or phase distribution of the alloy at multiple angles, and further realizes the control of the second phase segregation and dispersion. The method of the application can greatly save time and reduce the time cost of production.

[0018] 2) The application regulates the double-roller casting temperature to regulate the second phase morphology and distribution, thereby improving the corrosion resistance of the alloy. By regulating the second phase distribution, the application effectively reduces the potential difference between the aluminum matrix and the second phase, reduces the interface energy at the grain boundary and phase interface by regulating the element segregation, effectively hinders the continuous penetration of the corrosion channel, reduces the corrosion speed, delays and inhibits the occurrence of micro-electrode corrosion, inhibits the precipitation of corrosion products, and the alloy has excellent corrosion resistance;

[0019] 3) The double-roller casting temperature is controlled in the range of 660℃-730℃, so that the aluminum liquid has suitable fluidity, can promote the mixing of Al and Fe, Mn, Ti elements, and can avoid the phenomenon of aluminum liquid sticking to the roller caused by too low temperature and the product not forming caused by too high temperature;

[0020] 4) The 3003 aluminum alloy obtained by the method has an average grain size of ≤2μm and excellent corrosion resistance, and the preparation method meets the urgent requirements of large-scale, low-cost, and high-performance manufacturing of aluminum alloy components in the application environment. BRIEF DESCRIPTION OF DRAWINGS

[0021] The accompanying drawings are included to provide a further understanding of the application, and constitute a part of the specification, which together with the embodiments of the application, serve to explain the application, and do not constitute a limitation on the application. In the drawings:

[0022] Figure 1 The flowchart of the method of the application is shown in the figure;

[0023] Figure 2Microstructure and EDS element distribution of 3003 alloys along the rolling direction at different TRC temperatures;

[0024] Figure 3 The surface microstructure and elemental distribution of corrosion products of 3003 alloys immersed in 3.5 wt.% sodium chloride solution for 50 days at different TRC temperatures were investigated.

[0025] Figure 4 Microstructure and elemental distribution of corrosion products of 3003 alloys immersed in 3.5 wt.% sodium chloride solution at different TRC temperatures for 50 days;

[0026] Figure 5 Polarization curves of 3003 alloy at different TRC temperatures in 3.5 wt.% NaCl solution;

[0027] Figure 6 EIS spectra of 3003 alloy in 3.5 wt.% NaCl solution at different TRC temperatures: (a) Nyquist plot, (b) Bode plot, (c) EIS equivalent circuit. Detailed Implementation

[0028] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0029] Please see Figure 1 The present invention provides a technical solution: a 3003 aluminum alloy with high corrosion resistance, comprising the following components by mass percentage: Mn: 0.87-1.96%, Fe: 0.11-0.83%, Si: 0.17-1.13%, Cu: 0.09-1.43%, Zn: 0.01-0.18%, Ti: 0.01-0.23%, with the balance being Al and unavoidable impurities;

[0030] The purity of the Mn, Fe, Si, Cu, Zn and Ti elemental particles is >99.9%;

[0031] A casting and rolling process for high corrosion-resistant 3003 aluminum alloy, the process comprising the following steps:

[0032] S1, raw material configuration: the aluminum ingot is heated and melted under the protection of argon, and after complete melting, the melt composition is accurately adjusted according to the following chemical composition and mass percentage ratio: Mn: 0.87-1.96%, Fe: 0.11-0.83%, Si: 0.17-1.13%, Cu: 0.09-1.43%, Zn: 0.01-0.18%, Ti: 0.01-0.23%, the balance being Al and unavoidable impurities, after sufficient stirring, refining, degassing and slag removal, an alloy melt is obtained;

[0033] S2, plate casting and rolling: the alloy melt obtained in S1 is continuously cast and rolled by a casting nozzle into a double-roller casting and rolling equipment, the casting and rolling temperature is 660-730℃, the casting and rolling speed is 700-900mm / min, and the roller gap distance is 4-8mm, thereby obtaining a 3003 aluminum alloy plate;

[0034] S3, gas mist cooling: the 3003 aluminum alloy plate obtained in S2 is cooled through a plurality of gas mist cooling nozzles, the cooling rate of the gas mist cooling is 90-150℃ / s, and after the gas mist cooling, a slab is obtained, high-pressure gas is sprayed to the slab to blow off the cooling water and eliminate water marks on the surface of the slab;

[0035] S4, temperature-controlled coiling: the slab obtained in S3 is coiled at a controlled temperature to obtain a hot coil;

[0036] S5, offline finishing: the hot coil obtained in S4 is finished by using a tension leveling and flattening process to obtain a finished coil.

[0037] Comparative Example 1: aluminum alloy plate produced according to a conventional method

[0038] The alloy raw material is configured according to the following chemical composition and mass percentage ratio: Mn: 0.87-1.96wt.%; Fe: 0.11-0.83wt.%; Si: 0.17-1.13wt.%; Cu: 0.09-1.43wt.%; Zn: 0.01-0.18wt.%; Ti: 0.01-0.23wt.%; and the balance being Al and unavoidable impurities.

[0039] S1, the alloy ingot is heated to 600℃-630℃ and kept for 16h-24h for homogenization annealing treatment of the ingot;

[0040] S2, the preheated alloy ingot is hot-rolled and sawed;

[0041] S3, the hot-rolled alloy ingot is preheated, then hot-rolled, and the hot-rolled coil is rolled into a cold-rolled coil again, annealed, and a coil after annealing is obtained;

[0042] S4, the coil after annealing is straightened and shaped on a tension leveling and straightening machine, and cut to obtain an aluminum alloy plate.

[0043] Performance test shows that the average grain size of the core material of the aluminum alloy plate is less than or equal to 80 microns, and the sample is immersed in a 3.5wt% NaCl solution for 50 days, and the corrosion depth of the sample immersed for 50 days is about 75 microns.

[0044] Example 1

[0045] S1, raw material configuration: the aluminum ingot is heated and melted under the protection of argon, and after complete melting, the chemical composition and mass percentage ratio of the melt composition are precisely adjusted as follows: Mn: 0.87-1.96%, Fe: 0.11-0.83%, Si: 0.17-1.13%, Cu: 0.09-1.43%, Zn: 0.01-0.18%, Ti: 0.01-0.23%, and the balance is Al and unavoidable impurities. After sufficient stirring, refining, degassing and slag removal are performed to obtain an alloy melt;

[0046] S2, plate casting and rolling: the alloy melt obtained in S1 is continuously cast and rolled by a double-roller casting and rolling device through a casting nozzle, the casting and rolling temperature is 680°C, the casting and rolling speed is 700-900 mm / min, and the roll gap distance is 4-8 mm, thereby obtaining a 3003 aluminum alloy plate;

[0047] S3, gas mist cooling: the 3003 aluminum alloy plate obtained in S2 is cooled through a plurality of gas mist cooling nozzles, the cooling rate of the gas mist cooling is 90-150°C / s, and the plate blank is obtained after the gas mist cooling. High-pressure gas is sprayed to the plate blank to blow off the cooling water and eliminate water marks on the surface of the plate blank;

[0048] S4, temperature-controlled coiling: the plate blank obtained in S3 is temperature-controlled coiled to obtain a hot coil;

[0049] S5, offline finishing: the hot coil obtained in S4 is finished by using a tension leveling and flattening process to obtain a finished coil 1.

[0050] Example 2

[0051] The casting and rolling temperature is 690°C, and the remaining process steps are the same as those of Example 1, thereby obtaining a finished coil 2.

[0052] Example 3

[0053] The casting and rolling temperature is 700°C, and the remaining process steps are the same as those of Example 1, thereby obtaining a finished coil 3.

[0054] Example 4

[0055] The casting and rolling temperature is 710°C, and the remaining process steps are the same as those of Example 1, thereby obtaining a finished coil 4.

[0056] Example 5

[0057] The cast-rolling temperature was 720°C, and the remaining process steps were the same as in Example 1 to obtain finished coil 5.

[0058] The finished coils 1-5 obtained in Examples 1-5 were cut into samples with a length of 10-11 mm, a width of 10-11 mm, and a thickness of 4-8 mm by an electric spark cutting and a diamond wire cutting machine. The cross sections of the cut samples were polished and cleaned, and then ultrasonic treated in anhydrous ethanol for 600 s. The samples were then dipped in acetone with a full-ultrafine dust cloth and wiped on the surface of the coating for 1-2 min to further remove possible organic contaminants on the surface of the coating. Subsequently, the samples were washed with deionized water and dried in an oven at 50°C for 20 min to ensure that the surface moisture was completely volatilized to obtain the example samples 1-5. The microstructure and corrosion resistance of the samples were then characterized and tested, as follows:

[0059] Test 1: The surface of the sample was polished and etched, and then the microstructure of the sample was characterized by a scanning electron microscope (Apero S) equipped with an energy dispersive spectrometer (EDS);

[0060] Test 2: The surface of the sample was polished and then immersed in a 3.5wt% NaCl solution for 50 days. The microstructure of the sample was characterized by a scanning electron microscope (Apero S) equipped with an energy dispersive spectrometer (EDS);

[0061] Test 3: Electrochemical performance test. The sample was fixed with a conductive glue and a wire, and then inlaid with an epoxy resin solution. The inlaid sample was connected to a three-electrode chemical workstation. In the experiment, a platinum plate was used as the counter electrode, and a saturated calomel electrode (SCE) was used as the reference electrode. Before the open circuit potential (OCP) measurement, the sample was immersed in a 3.5wt% NaCl aqueous solution for 90 minutes to achieve electrochemical stability. The polarization test was performed within a potential range of ±1 mV relative to the OCP, and the scanning rate was 1 mV / s. The electrochemical impedance spectroscopy (EIS) test was performed at the open circuit potential, with an amplitude of 5 mV and a frequency range of 0.1 Hz to 10 kHz.

[0062] See Table Figures 2-6 , and the test results are as follows:

[0063] Example sample 1

[0064] Test 1: The sample was characterized to consist of an aluminum matrix and a second phase rich in iron and manganese, and the silicon element was uniformly distributed in the matrix. The second phase showed a continuous growth morphology along the rolling direction.

[0065] Test 2: The sample surface showed a layered corrosion product with cracking and peeling. EDS analysis showed that the layered corrosion product was significantly enriched with Cl and O elements. The corrosion depth after 50 days of immersion was about 55.10 μm.

[0066] Test 3: The test obtained the self-corrosion potential of the sample as -1.08 V, the self-corrosion current density as 8.03 x 10-6 A / cm2, the corrosion product resistance Rf as 21110 Ω·cm2, and the charge transfer resistance Rct as 107.1 Ω·cm2.

[0067] Example Sample 2

[0068] Test 1: Characterization obtained that the sample was composed of an aluminum matrix and a second phase rich in iron and manganese, and the silicon element was uniformly distributed in the matrix, and the second phase began to decompose into discrete particles;

[0069] Test 2: The sample surface appeared granular corrosion products, EDS analysis showed that the granular corrosion products appeared Cl and O element enrichment; the corrosion depth of 50 days of immersion was about 37.80 μm;

[0070] Test 3: The test obtained the self-corrosion potential of the sample as -1.01 V, the self-corrosion current density as 8.36 x 10-6 A / cm2, the corrosion product resistance Rf as 29610 Ω·cm2, and the charge transfer resistance Rct as 230.5 Ω·cm2.

[0071] Example Sample 3

[0072] Test 1: Characterization obtained that the sample was composed of an aluminum matrix and a second phase rich in iron and manganese, and the silicon element was uniformly distributed in the matrix, and the second phase was a dispersed particle;

[0073] Test 2: The sample surface appeared granular corrosion products, EDS analysis showed that the granular corrosion products appeared Cl and O element enrichment; the corrosion depth of 50 days of immersion was about 1.47 μm;

[0074] Test 3: The test obtained the self-corrosion potential of the sample as -0.92 V, the self-corrosion current density as 9.39 x 10-7 A / cm2, the corrosion product resistance Rf as 93089 Ω·cm2, and the charge transfer resistance Rct as 318.0 Ω·cm2.

[0075] Example Sample 4

[0076] Test 1: Characterization obtained that the sample was composed of an aluminum matrix and a second phase rich in iron and manganese, and the silicon element was uniformly distributed in the matrix, and the second phase particles re-aggregated and preferentially grew along the rolling direction;

[0077] Test 2: The sample surface appeared granular corrosion products gradually forming clusters, EDS analysis showed that the granular corrosion products appeared Cl and O element enrichment; the corrosion depth of 50 days of immersion was about 35.67 μm;

[0078] Test 3: The test results of the sample are as follows: the self-corrosion potential is-0.92V, the self-corrosion current density is 8.18*10-6A / cm2, the corrosion product resistance Rf is 71502Ω·cm2, and the charge transfer resistance Rct is 261.8Ω·cm2.

[0079] Example sample 5

[0080] Test 1: The sample is characterized to consist of an aluminum matrix and a second phase rich in iron and manganese, and the silicon element is uniformly distributed in the matrix, and the second phase particles are re-aggregated.

[0081] Test 2: Corrosion particle aggregation and layered product peeling occur on the surface of the sample, and EDS analysis shows that the layered corrosion product is rich in Cl and O elements; the corrosion depth of the sample immersed for 50 days is about 51.11μm.

[0082] Test 3: The test results of the sample are as follows: the self-corrosion potential is-0.94V, the self-corrosion current density is 8.07*10-6A / cm2, the corrosion product resistance Rf is 57653Ω·cm2, and the charge transfer resistance Rct is 182.1Ω·cm2.

[0083] From the test results, it can be seen that:

[0084] The present application directly regulates the temperature of double-roller casting, changes the internal structure, grain size, orientation or phase distribution of the alloy at multiple angles, and further realizes the control of the second phase segregation and dispersion. The method of the present application can greatly save time and reduce the time cost of production.

[0085] The present application regulates the temperature of double-roller casting to regulate the morphology and distribution of the second phase, thereby improving the corrosion resistance of the alloy. By regulating the distribution of the second phase, the present application effectively reduces the potential difference between the aluminum matrix and the second phase, reduces the interface energy by regulating the element segregation at the grain boundary and phase interface, effectively hinders the continuous connection of the corrosion channel, reduces the corrosion speed, delays and inhibits the occurrence of micro-electrode corrosion, and inhibits the precipitation of corrosion products. The alloy has excellent corrosion resistance.

[0086] The temperature of double-roller casting is controlled at 660℃-730℃, which makes the aluminum liquid have suitable fluidity, promotes the mixing of Al with Fe, Mn and Ti elements, and avoids the phenomenon of product not forming caused by too low temperature or too high temperature.

[0087] The 3003 aluminum alloy obtained by the method of the present application has an average grain size of ≤2μm and excellent corrosion resistance, and the preparation method meets the urgent requirements of large-scale, low-cost and high-performance for the manufacture of aluminum alloy components in application environment.

[0088] Finally, it should be noted that the above only describes the preferred embodiments of the present application and is not intended to limit the present application. Although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art will appreciate that the technical solutions described in the foregoing embodiments can be modified or some technical features thereof can be replaced by equivalent ones. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A 3003 aluminum alloy having high corrosion resistance, characterized by, By mass percentage, the alloy comprises the following components: Mn: 0.87-1.96%, Fe: 0.11-0.83%, Si: 0.17-1.13%, Cu: 0.09-1.43%, Zn: 0.01-0.18%, Ti: 0.01-0.23%, and the balance of Al and inevitable impurities.

2. The 3003 aluminum alloy with high corrosion resistance according to claim 1, characterized in that: The purity of the Mn, Fe, Si, Cu, Zn and Ti element particles is greater than 99.9%.

3. A cast-rolling production process of 3003 aluminum alloy with high corrosion resistance, characterized in that, The production process comprises the following steps: S1, raw material configuration: an aluminum ingot is heated and melted under argon protection, the composition of the melt is accurately adjusted according to the requirements of claim 1 after complete melting, and the melt is refined, degassed and cleaned after sufficient stirring, thereby obtaining an alloy melt; S2, plate casting and rolling: the alloy melt obtained in S1 is continuously cast and rolled by a double-roller casting and rolling device through a casting nozzle, the casting and rolling temperature is 660-730°C, and a 3003 aluminum alloy plate is obtained; S3, gas mist cooling: the 3003 aluminum alloy plate obtained in S2 is cooled through a plurality of gas mist cooling nozzles, the plate blank is obtained after gas mist cooling, high-pressure gas is sprayed to the plate blank to blow off the cooling water and eliminate water marks on the surface of the plate blank; S4, temperature-controlled coiling: the plate blank obtained in S3 is temperature-controlled coiled to obtain a hot coil; S5, offline finishing: the hot coil obtained in S4 is finished by using a stretch-straightening and flattening process to obtain a finished coil.

4. The cast-rolling production process of 3003 aluminum alloy with high corrosion resistance according to claim 3, characterized in that: The process parameters of the double-roller casting and rolling device in S2 are as follows: casting and rolling speed: 700-900 mm / min, and roller gap: 4-8 mm.

5. The cast-rolling production process of 3003 aluminum alloy with high corrosion resistance according to claim 3, characterized in that: The cooling rate of the gas mist cooling in S3 is 90-150°C / s.

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