CN112877624B - Corrosion-resistant Al-Zn-Mg-Cu alloy, and preparation method and application thereof - Google Patents
Corrosion-resistant Al-Zn-Mg-Cu alloy, and preparation method and application thereof Download PDFInfo
- Publication number
- CN112877624B CN112877624B CN202110044558.XA CN202110044558A CN112877624B CN 112877624 B CN112877624 B CN 112877624B CN 202110044558 A CN202110044558 A CN 202110044558A CN 112877624 B CN112877624 B CN 112877624B
- Authority
- CN
- China
- Prior art keywords
- percent
- alloy
- treatment
- corrosion
- preparation
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Images
Classifications
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22F—CHANGING THE PHYSICAL STRUCTURE OF NON-FERROUS METALS AND NON-FERROUS ALLOYS
- C22F1/00—Changing the physical structure of non-ferrous metals or alloys by heat treatment or by hot or cold working
- C22F1/04—Changing the physical structure of non-ferrous metals or alloys by heat treatment or by hot or cold working of aluminium or alloys based thereon
- C22F1/053—Changing the physical structure of non-ferrous metals or alloys by heat treatment or by hot or cold working of aluminium or alloys based thereon of alloys with zinc as the next major constituent
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C1/00—Making non-ferrous alloys
- C22C1/02—Making non-ferrous alloys by melting
- C22C1/026—Alloys based on aluminium
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C21/00—Alloys based on aluminium
- C22C21/10—Alloys based on aluminium with zinc as the next major constituent
Abstract
The invention discloses a corrosion-resistant Al-Zn-Mg-Cu alloy, a preparation method and application thereof, and relates to the technical field of aluminum alloys. The preparation method of the corrosion-resistant Al-Zn-Mg-Cu alloy comprises the steps of smelting raw materials to form an alloy ingot, and sequentially carrying out two-stage homogenization, deformation processing, intermediate annealing, solution quenching and regression re-aging treatment; by adding a proper amount of Zr, Sc and other elements into the Al-Zn-Mg-Cu alloy and matching with the processes of double-stage homogenization, deformation processing, intermediate annealing, solution quenching and regression re-aging treatment, the formation of a high-strength Brass texture is promoted, the stress corrosion resistance and the spalling corrosion resistance of the Al-Zn-Mg-Cu alloy are greatly improved, and the high tensile strength is kept. Can be used for preparing aviation components, automobiles, rail transit or marine ships and has good industrial application prospect.
Description
Technical Field
The invention relates to the technical field of aluminum alloys, in particular to a corrosion-resistant Al-Zn-Mg-Cu alloy, and a preparation method and application thereof.
Background
Al-Zn-Mg-Cu alloy is attracting attention as an important light alloy structural material due to its low density and ultra-high strength. The Al-Zn-Mg-Cu alloy has high strength after solution quenching peak aging (T6) treatment, but shows poor stress corrosion resistance and spalling corrosion resistance. At present, the main method for improving the corrosion resistance of the alloy is to adjust and control the size and distribution of second particles in an intragranular and a grain boundary by improving an aging treatment process so as to obtain a corrosion-resistant microstructure of the alloy. After the Al-Zn-Mg-Cu alloy is subjected to aging (T7), the grain boundary and the intragranular grains are coarsened, and particularly, the grain boundary precipitated phase is discontinuously distributed, so that the stress corrosion cracking resistance of the alloy is improved, but the strength of the alloy is obviously reduced.
Israel scientist Cina proposed a regression re-aging (RRA) treatment in the last 70 th century to improve the stress corrosion resistance of Al-Zn-Mg-Cu alloys without sacrificing more alloy strength. The regression and reaging comprises three stages of first-stage pre-ageing, second-stage regression and third-stage reaging treatment. Wherein, the G.P. region precipitated by pre-aging and the thinner eta' phase are dissolved back in the regression process, the alloy is softened, and the grain boundary precipitated phase is coarsened and gradually separated; during the subsequent re-ageing process, G.P. zone and fine eta' phase strengthening phase particles are separated out from the crystal interior, and the grain boundary separated phase is further grown and distributed discontinuously. The intragranular and grain boundary structural characteristics are beneficial to ensuring the strength performance of the alloy and reducing the corrosion cracking sensitivity of the alloy.
In recent years, patents and documents related to the development of corrosion resistant Al-Zn-Mg-Cu alloys in China are focused on the field of two-stage aging and regression re-aging process improvement. When the corrosion resistance of the alloy is improved by using overaging, double-stage aging and regression and reaging processes, the problems of unsatisfactory improvement of the corrosion resistance, uneven corrosion resistance, great influence on the strength of the alloy and the like still exist.
Disclosure of Invention
The invention aims to provide a corrosion-resistant Al-Zn-Mg-Cu alloy and a preparation method thereof, and aims to obtain an alloy material with good corrosion resistance and high mechanical strength.
The invention also aims to provide application of the corrosion-resistant Al-Zn-Mg-Cu alloy in preparing aviation components, automobiles, rail transit or marine ships.
The technical problem to be solved by the invention is realized by adopting the following technical scheme.
The invention provides a preparation method of a corrosion-resistant Al-Zn-Mg-Cu alloy, which comprises the steps of smelting raw materials to form an alloy ingot, and sequentially carrying out two-stage homogenization, deformation processing, intermediate annealing, solution quenching and regression reaging treatment;
the raw materials are proportioned according to the following alloy compositions in percentage by weight: 7.5 to 8.3 percent of Zn, 1.6 to 2.0 percent of Mg, 1.8 to 2.2 percent of Cu, 0.01 to 0.05 percent of Mn, 0.03 to 0.18 percent of Zr, 0.01 to 0.05 percent of Sc, less than or equal to 0.05 percent of Fe, less than or equal to 0.05 percent of Si, and the balance of Al, wherein the weight ratio of Zr to Sc is 2.0 to 3.5.
The invention also provides a corrosion-resistant Al-Zn-Mg-Cu alloy which is prepared by the preparation method; preferably, the Brass texture orientation strength of the alloy matrix is more than or equal to 15, and the proportion of the fiber-shaped crystal grains is more than or equal to 70%.
The invention also provides application of the corrosion-resistant Al-Zn-Mg-Cu alloy in preparation of aviation elements, automobiles, rail transit or marine ships.
The embodiment of the invention provides a preparation method of a corrosion-resistant Al-Zn-Mg-Cu alloy, which is characterized in that a proper amount of Zr, Sc and other elements are added into the Al-Zn-Mg-Cu alloy, and the formation of a high-strength Brass texture is promoted by matching with the processes of two-stage homogenization, deformation processing, intermediate annealing, solution quenching and regression re-aging treatment, so that the stress corrosion resistance and the spalling corrosion resistance of the Al-Zn-Mg-Cu alloy are greatly improved, and high tensile strength is kept. Can be used for preparing aviation components, automobiles, rail transit or marine ships and has good industrial application prospect.
It is necessary to supplement that through the improvement of element composition and process, dispersed nanometer second phase particles with the functions of inhibiting braking and static recrystallization can be obtained, and the particles can inhibit dynamic recrystallization and promote the formation of Brass texture with higher strength when being extruded and deformed at high strain rate and large deformation amount.
Drawings
In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings needed to be used in the embodiments will be briefly described below, it should be understood that the following drawings only illustrate some embodiments of the present invention and therefore should not be considered as limiting the scope, and for those skilled in the art, other related drawings can be obtained according to the drawings without inventive efforts.
FIG. 1 is a metallographic view of a wall thickness cross section of an alloy thin-walled extruded material obtained in example 1;
FIG. 2 is a metallographic view showing a wall thickness cross section of the alloy thin-walled extruded material obtained in comparative example 1.
Detailed Description
In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. The examples, in which specific conditions are not specified, were conducted under conventional conditions or conditions recommended by the manufacturer. The reagents or instruments used are not indicated by the manufacturer, and are all conventional products available commercially.
The corrosion-resistant Al-Zn-Mg-Cu alloy provided by the embodiment of the invention, the preparation method and the application thereof are specifically explained below.
The inventor creatively changes the original mode of improving the corrosion resistance of the alloy through a single aging process, improves the orientation (texture) and grain boundary orientation property of crystal grains, improves the grain boundary second phase structure of the alloy and further influences the corrosion resistance of the alloy. The inventor creatively improves the corrosion resistance of the Al-Zn-Mg-Cu alloy by improving the Brass texture strength of the alloy.
It is necessary to supplement that the high-energy and high-angle grain boundary can improve the grain boundary nucleation rate of the aging precipitation phase, and promote the continuous precipitation and the broadening of a precipitation-free precipitation zone of the grain boundary precipitation phase, so that the stress corrosion, the exfoliation corrosion and the intergranular corrosion sensitivity of the alloy can be increased. While the low energy, low angle grain boundaries provide relatively fewer nucleation sites for the second phase, resulting in the formation of an intermittent distribution of grain boundary second phase particles upon aging, which is beneficial to the improvement of the corrosion resistance of the alloy. The Brass texture can be obtained by rolling or extruding with larger deformation amount in the aluminum alloy, and the deformed grain bands with the Brass texture orientation obtained under the deformation condition have the characteristics of high proportion of small-angle grain boundaries and slender grain fibers (large length-width ratio). The high proportion of low-angle grain boundaries is beneficial to forming a corrosion-resistant structure with coarse and intermittent grain boundary second phases in the aging process of the alloy, and the slender fibrous grains have the functions of increasing the physical stroke of crystal corrosion cracking along the grain boundary and further slowing or blocking the development of the corrosion cracking to the core of the material.
The embodiment of the invention provides a preparation method of a corrosion-resistant Al-Zn-Mg-Cu alloy, which comprises the steps of smelting raw materials to form an alloy ingot, and sequentially carrying out two-stage homogenization, deformation processing, intermediate annealing, solution quenching and regression re-aging treatment.
It should be noted that, in the embodiment of the present invention, the stress corrosion resistance and the exfoliation corrosion resistance of the Al-Zn-Mg-Cu alloy can be greatly improved by designing alloy components, homogenizing, deforming, annealing, and solution-treating to obtain a high strength Brass texture and a high proportion fiber crystal structure, and then combining with the regression re-aging treatment. In addition, the Zr and Sc elements have additional strengthening effect on the dispersed nano-phase particles formed by homogenization, so that the Al-Zn-Mg-Cu alloy has improved corrosion resistance and high tensile strength.
The specific process comprises the following steps:
s1, forming alloy ingot
The raw materials are mixed according to the following alloy compositions in percentage by weight: 7.5 to 8.3 percent of Zn, 1.6 to 2.0 percent of Mg, 1.8 to 2.2 percent of Cu, 0.01 to 0.05 percent of Mn, 0.03 to 0.18 percent of Zr, 0.01 to 0.05 percent of Sc, less than or equal to 0.05 percent of Fe, less than or equal to 0.05 percent of Si, and the balance of Al, wherein the weight ratio of Zr to Sc is 2.0 to 3.5. Then, the alloy ingot is formed by adopting the existing preparation process of the alloy ingot, the steps of smelting, refining and the like are included, and the process refers to the existing process and is not described in detail herein.
The inventor finds that the addition of a proper amount of elements such as Zr and Sc to the Al-Zn-Mg-Cu alloy and the appropriate homogenization treatment can obtain dispersed nano second phase particles with braking inhibiting and static recrystallization effects, and the particles can inhibit dynamic recrystallization and promote the formation of a Brass texture with higher strength during extrusion deformation with high strain rate and large deformation amount.
The dosage of each component has great influence on the formation of the high-strength Brass texture, particularly the weight ratio Zr/Sc is more remarkable, and if the dosage exceeds the range, the high-strength alloy is not favorably obtained.
In order to further improve the corrosion resistance and the mechanical strength of the alloy, the inventor further optimizes the composition of the alloy. In a preferred embodiment, the alloy has the composition, in weight percent: 7.8 to 8.1 percent of Zn, 1.8 to 2.0 percent of Mg, 1.9 to 2.1 percent of Cu, 0.02 to 0.04 percent of Mn, 0.13 to 0.18 percent of Zr, 0.03 to 0.04 percent of Sc, less than or equal to 0.05 percent of Fe, less than or equal to 0.05 percent of Si, and the balance of Al, wherein the weight ratio of Zr to Sc is 2.6 to 3.0.
S2, deformation processing and heat treatment
The embodiment of the invention sequentially carries out two-stage homogenization, deformation processing, intermediate annealing, solution quenching and regression re-aging treatment, and can obtain the alloy with good corrosion resistance and high mechanical strength by matching with the adjustment of the components, the prepared Al-Zn-Mg-Cu alloy thin-wall section has the tensile strength of 608-663MPa, the yield strength of 557-618MPa, the elongation of 9.1-12.8 percent, the slow strain tensile corrosion fracture time of 60-85h and the exfoliation corrosion sensitivity grade of EA or P.
Further, Al having an effect of suppressing recrystallization is subjected to two-stage homogenization treatment3(Sc1-x,Zrx) The dispersed nano-phase particles are formed during the first-stage low-temperature homogenizing annealing, and the particles of the type can inhibit the dynamic recrystallization of the alloy in the alloy deformation processing process, so that a deformed grain structure with a high-proportion fiber form is obtained. The annealing treatment is beneficial to further improving the strength of the brass texture in the recovery process, simultaneously consumes the recrystallization driving force and is matched with the inhibition of the recrystallization Al3(Sc1-x,Zrx) The particles act to cause the alloy to recrystallize to a lesser extent during solution treatment, so that the alloy ultimately retains a high strength Brass texture and maintains a high proportion of the crystallite morphology. Furthermore, the Brass texture with high proportion of low-angle grain boundaries is beneficial to forming a corrosion-resistant structure with coarse and intermittent distribution of grain boundary second phases in the aging process of the alloy, and the elongated fibrous grains have the function of increasing the physical stroke of crystal corrosion cracking and further slowing or blocking the development of the corrosion cracking to the core of the material. Therefore, the regression and re-aging process is combined to obtain a uniform corrosion-resistant crystal boundary structure, the corrosion resistance of the Al-Zn-Mg-Cu alloy is greatly improved, and meanwhile, the Al3(Sc1-x,Zrx) The dispersed nanophase particles have an additional strengthening effect, thereby enabling Al-Zn-MThe g-Cu alloy has improved corrosion resistance and high room-temperature tensile mechanical strength.
Further, the two-stage homogenization comprises a first-stage homogenization treatment and a second-stage homogenization treatment, wherein the treatment temperature of the first-stage homogenization treatment is 365-390 ℃, and the treatment temperature of the second-stage homogenization treatment is 465-472 ℃; the treatment time of the first-stage homogenization treatment is 3-6h, and the treatment time of the second-stage homogenization treatment is 12-24 h. By optimizing the two-stage homogenization process, the deformed grain structure with a high proportion of fiber morphology can be obtained.
Furthermore, the deformation processing adopts an extrusion deformation method, and a thin-wall section with the thickness of 3-18mm is formed after extrusion deformation is controlled. In a preferred embodiment, the extrusion deformation is realized by adopting a rapid extrusion mode, the extrusion speed is controlled to be greater than or equal to 4.5m/min, the extrusion temperature of the blank is controlled to be 390-420 ℃ in the rapid extrusion process, and the extrusion ratio is controlled to be greater than or equal to 25. The rapid large extrusion ratio deformation process is beneficial to the primary formation of stronger Brass texture of the alloy.
Furthermore, the operation temperature of the intermediate annealing process is controlled to be 280-320 ℃, and the operation time is 1.5-4 h. The inventor finds that the strength of the Brass texture can be further improved by rotating the nearly Brass oriented crystal grains to the Brass orientation in the recovery process by adopting the low-temperature annealing process, and simultaneously, the recrystallization driving force in the solution treatment is reduced in the recovery process, so that the Brass texture and the fiber crystal texture are kept stable in the solution treatment process, and the high-strength Brass texture and the high-proportion fiber crystal texture are obtained.
Further, the solution quenching is to carry out solution treatment for 20-75min at 465-475 ℃, and then quench and cool. In some embodiments, the quench cooling is cooling in water to room temperature.
Further, the regression and reaging comprises three stages of first-stage preaging, second-stage regression and third-stage reaging, wherein the treatment temperature of the first-stage preaging is 105-120 ℃, and the treatment time is 20-30 h; the treatment temperature of the second-stage regression is 175-190 ℃, and the treatment time is 6-20 min; the treatment temperature of the third-stage re-aging is 105-120 ℃, and the treatment time is 20-30 h. The regression re-aging needs to be matched with the processes of low-temperature annealing and solution quenching to obtain a uniform corrosion-resistant crystal boundary structure, so that the corrosion resistance of the Al-Zn-Mg-Cu alloy is greatly improved, and high mechanical strength is kept.
The embodiment of the invention also provides a corrosion-resistant Al-Zn-Mg-Cu alloy which is prepared by the preparation method and has the characteristics of high orientation strength of the Brass texture and high proportion of fiber form crystal grains, wherein the orientation strength of the Brass texture of an alloy matrix is more than or equal to 15, and the proportion of the fiber form crystal grains is more than or equal to 70%.
The alloy material has excellent corrosion resistance and very good mechanical strength, can be applied to the preparation of aviation elements, automobiles, rail transit or marine ships, and particularly has wide application prospect in the field of marine ship manufacturing with extremely high requirement on the corrosion resistance of the alloy.
The features and properties of the present invention are described in further detail below with reference to examples.
Example 1
The embodiment provides a preparation method of a corrosion-resistant Al-Zn-Mg-Cu alloy, which comprises the following steps:
(1) the alloy ingot is formed by proportioning the following components in percentage by weight: 8.1% of Zn, 1.8% of Mg, 2.0% of Cu, 0.02% of Mn, 0.12% of Zr, 0.04% of Sc (Zr/Sc is 3.0), less than or equal to 0.05% of Fe, less than or equal to 0.05% of Si and the balance of Al.
(2) The alloy cast ingot is subjected to two-stage homogenization treatment at 380 ℃/4h +468 ℃/20h, then the cast ingot blank is preheated to 405 ℃, and the thin-wall section with the wall thickness of 6mm is obtained by rapid extrusion molding under the conditions that the extrusion ratio is 35 and the section extrusion speed is 5 m/min. Then the thin-wall section is subjected to intermediate annealing treatment at the temperature of 305 ℃/3h, then solid solution treatment at the temperature of 470 ℃/50min is carried out, the thin-wall section is quenched in water to room temperature, then regression re-aging treatment at the temperature of 108 ℃/24h +185 ℃/10min +108 ℃/24h is carried out, and then air cooling is carried out.
Example 2
The embodiment provides a preparation method of a corrosion-resistant Al-Zn-Mg-Cu alloy, which comprises the following steps:
(1) the alloy ingot is formed by proportioning the following components in percentage by weight: 8.1 percent of Zn, 1.8 percent of Mg, 2.0 percent of Cu, 0.02 percent of Mn, 0.10 percent of Zr, 0.03 percent of Sc (Zr/Sc is 3.3 percent), less than or equal to 0.05 percent of Fe, less than or equal to 0.05 percent of Si, and the balance of Al.
(2) The alloy cast ingot is subjected to two-stage homogenization treatment at 380 ℃/5h +468 ℃/20h, then the cast ingot blank is preheated to 415 ℃, and the thin-wall section with the wall thickness of 6mm is obtained by rapid extrusion molding under the conditions that the extrusion ratio is 35 and the section extrusion speed is 5 m/min. Then the thin-wall section is subjected to intermediate annealing treatment at the temperature of 310 ℃/2.5h, then solid solution treatment at the temperature of 470 ℃/50min is carried out, the thin-wall section is quenched in water to room temperature, then regression re-aging treatment is carried out at the temperature of 110 ℃/24h +185 ℃/10min +110 ℃/24h (namely the treatment temperature of the first-stage pre-aging treatment is 110 ℃, the treatment time is 24h, the treatment temperature of the second-stage regression treatment is 185 ℃, the treatment time is 10min, the treatment temperature of the third-stage re-aging treatment is 110 ℃, and the treatment time is 24h), and then air cooling is carried out.
Example 3
The embodiment provides a preparation method of a corrosion-resistant Al-Zn-Mg-Cu alloy, which comprises the following steps:
(1) the alloy ingot is formed by proportioning the following components in percentage by weight: 8.1% of Zn, 1.8% of Mg, 2.0% of Cu, 0.02% of Mn, 0.13% of Zr, 0.05% of Sc (Zr/Sc is 2.6), less than or equal to 0.05% of Fe, less than or equal to 0.05% of Si and the balance of Al.
(2) Carrying out two-stage homogenization treatment on an alloy cast ingot at 365 ℃/4h +468 ℃/20h, then preheating an ingot blank to 405 ℃, and carrying out rapid extrusion molding under the conditions that the extrusion ratio is 35 and the profile extrusion speed is 5m/min to obtain a thin-wall profile with the wall thickness of 6 mm. Then the thin-wall section is subjected to intermediate annealing treatment at a speed of 310 ℃/2.5h, then solid solution treatment at a speed of 470 ℃/75min is carried out, the thin-wall section is quenched in water to room temperature, then regression re-aging treatment at a speed of 110 ℃/24h +185 ℃/15min +110 ℃/24h is carried out, and then air cooling is carried out.
Example 4
The embodiment provides a preparation method of a corrosion-resistant Al-Zn-Mg-Cu alloy, which comprises the following steps:
(1) the alloy ingot is formed by proportioning the following components in percentage by weight: 7.5 percent of Zn, 1.8 percent of Mg, 2.0 percent of Cu, 0.02 percent of Mn, 0.13 percent of Zr, 0.05 percent of Sc (Zr/Sc is 2.6), less than or equal to 0.05 percent of Fe, less than or equal to 0.05 percent of Si, and the balance of Al.
(2) Carrying out two-stage homogenization treatment on an alloy cast ingot at 365 ℃/4h +468 ℃/20h, then preheating an ingot blank to 405 ℃, and carrying out rapid extrusion molding under the conditions that the extrusion ratio is 38 and the profile extrusion speed is 5m/min to obtain a thin-wall profile with the wall thickness of 6 mm. Then the thin-wall section is subjected to intermediate annealing treatment at a speed of 310 ℃/2.5h, then solid solution treatment at a speed of 470 ℃/75min is carried out, the thin-wall section is quenched in water to room temperature, then regression re-aging treatment at a speed of 110 ℃/24h +185 ℃/15min +110 ℃/24h is carried out, and then air cooling is carried out.
Example 5
The embodiment provides a preparation method of a corrosion-resistant Al-Zn-Mg-Cu alloy, which comprises the following steps:
(1) the alloy ingot is formed by proportioning the following components in percentage by weight: 7.5 percent of Zn, 1.6 percent of Mg, 1.8 percent of Cu, 0.01 percent of Mn, 0.03 percent of Zr, 0.01 percent of Sc (Zr/Sc is 3.0), less than or equal to 0.05 percent of Fe, less than or equal to 0.05 percent of Si, and the balance of Al.
(2) The alloy ingot is subjected to two-stage homogenization treatment at 370 ℃/6h +465 ℃/24h, then ingot blank is preheated to 390 ℃, and the thin-wall section with the wall thickness of 6mm is obtained by rapid extrusion molding under the conditions that the extrusion ratio is 25 and the section extrusion speed is 4.5 m/min. Then the thin-wall section is subjected to intermediate annealing treatment of 280 ℃/4h, then solid solution treatment of 465 ℃/75min is carried out, the thin-wall section is quenched in water to room temperature, then regression re-aging treatment of 105 ℃/30h +175 ℃/20min +105 ℃/30h is carried out, and then air cooling is carried out.
Example 6
The embodiment provides a preparation method of a corrosion-resistant Al-Zn-Mg-Cu alloy, which comprises the following steps:
(1) the alloy ingot is formed by proportioning the following components in percentage by weight: 8.3 percent of Zn, 2.0 percent of Mg, 2.2 percent of Cu, 0.05 percent of Mn, 0.175 percent of Zr, 0.05 percent of Sc (Zr/Sc is 3.5), less than or equal to 0.05 percent of Fe, less than or equal to 0.05 percent of Si, and the balance of Al.
(2) Carrying out two-stage homogenization treatment on the alloy ingot casting at 390 ℃/3h +472 ℃/12h, then preheating the ingot casting blank to 420 ℃, and carrying out rapid extrusion molding under the conditions that the extrusion ratio is 35 and the profile extrusion speed is 5m/min to obtain the thin-wall profile with the wall thickness of 6 mm. Then the thin-wall section is subjected to intermediate annealing treatment at 320 ℃/1.5h, then solid solution treatment at 475 ℃/20min is carried out, the thin-wall section is quenched in water to room temperature, then regression re-aging treatment at 120 ℃/20h +190 ℃/6min +120 ℃/20h is carried out, and then air cooling is carried out.
Comparative example 1
The comparative example provides a method of making an Al-Zn-Mg-Cu alloy, comprising:
(1) the alloy ingot is formed by batching according to the alloy components, and the alloy components are as follows: 6.5 percent of Zn, 1.8 percent of Mg, 2.0 percent of Cu, 0.02 percent of Mn, 0.13 percent of Zr, less than or equal to 0.05 percent of Fe, less than or equal to 0.05 percent of Si, and the balance of Al.
(2) Homogenizing the alloy ingot at 468 ℃/26h, preheating the ingot blank to 405 ℃, and rapidly extruding and forming under the conditions that the extrusion ratio is 38 and the profile extrusion speed is 5m/min to obtain the thin-wall profile with the wall thickness of 6 mm. Then the thin-wall section is subjected to solution treatment at 470 ℃/75min, quenched in water to room temperature, subjected to regression re-aging treatment at 110 ℃/24h +185 ℃/15min +110 ℃/24h, and then air-cooled.
Comparative example 2
The comparative example provides a method of making an Al-Zn-Mg-Cu alloy, comprising:
(1) the alloy ingot is formed by batching according to the alloy components, and the alloy components are as follows: 8.1 percent of Zn, 1.8 percent of Mg, 2.0 percent of Cu, 0.02 percent of Mn, 0.18 percent of Zr, 0.06 percent of Sc (Zr/Sc is 3.0), less than or equal to 0.05 percent of Fe, less than or equal to 0.05 percent of Si, and the balance of Al.
(2) Homogenizing the alloy ingot at 468 deg.C/26 h, preheating the ingot blank to 405 deg.C, and extruding at extrusion ratio of 18 and profile extrusion speed of 2m/min to obtain thin-wall profile with wall thickness of 6 mm. Then the thin-wall section is subjected to solution treatment at 470 ℃/75min, quenched in water to room temperature, subjected to peak aging treatment at 110 ℃/24h and then air-cooled.
Comparative example 3
This comparative example provides a method for producing an Al-Zn-Mg-Cu alloy, which is different from example 1 only in that: the alloy comprises the following components: 8.1% of Zn, 1.8% of Mg, 2.0% of Cu, 0.02% of Mn, 0.16% of Zr, 0.04% of Sc (Zr/Sc is 4.0), less than or equal to 0.05% of Fe, less than or equal to 0.05% of Si and the balance of Al.
Comparative example 4
This comparative example provides a method for producing an Al-Zn-Mg-Cu alloy, which is different from example 1 only in that: the alloy comprises the following components: 8.1% of Zn, 1.8% of Mg, 2.0% of Cu, 0.02% of Mn, 0.06% of Zr, 0.04% of Sc (Zr/Sc is 1.5), less than or equal to 0.05% of Fe, less than or equal to 0.05% of Si and the balance of Al.
Comparative example 5
This comparative example provides a method for producing an Al-Zn-Mg-Cu alloy, which is different from example 1 only in that: the process of low-temperature annealing is not adopted, and the annealing temperature is 380 ℃/3 h.
Comparative example 6
This comparative example provides a method for producing an Al-Zn-Mg-Cu alloy, which is different from example 1 only in that: the rapid extrusion process is not adopted, and the extrusion rate is 2 m/min.
Comparative example 7
This comparative example provides a method for producing an Al-Zn-Mg-Cu alloy, which is different from example 1 only in that: abandon two-stage homogenization and only adopt single-stage homogenization, wherein the homogenization process is 468 ℃/24 h.
The results show that the alloy of comparative example 7, after spalling corrosion, showed severe delamination and significantly poorer corrosion resistance than example 1.
Comparative example 8
This comparative example provides a method for producing an Al-Zn-Mg-Cu alloy, which is different from example 1 only in that: abandoning RRA treatment, adopting single-stage overaging treatment: 120 ℃/48 h.
The results show that the tensile strength of the comparative example 8 is 586MPa, the yield strength is 528MPa, and the room-temperature tensile property of the alloy is obviously reduced by adopting the overaging treatment compared with the example 1.
Test example 1
The alloy materials prepared in examples 1 to 6 and comparative examples 1 to 6 were tested for tensile strength, yield strength, elongation, Brass texture strength, ratio of fibrous crystals, stress corrosion cracking time, and exfoliation corrosion rating, and the results are shown in table 1. The test of tensile strength, yield strength and elongation rate refers to GB 228-87, the Brass texture strength is obtained by XRD test, the fiber crystal proportion is determined by metallographic test statistics, the test of stress corrosion fracture time refers to GB/T15970, and the test of spalling corrosion grade refers to GB/T22639-2008.
TABLE 1 Performance test results of the alloys
From the structure and performance results in Table 1, it can be seen that the alloys of examples 1-4 have a higher Brass texture orientation strength after final treatment, while the grains are dominated by a high proportion of fibrous grains and exhibit lower stress corrosion and exfoliation corrosion susceptibility (stress corrosion cracking time >60h, exfoliation corrosion susceptibility: EA or P).
The comparative example 1 does not contain Sc, adopts the traditional single RRA treatment, does not adopt the early stage two-stage homogenization, rapid extrusion and intermediate annealing process for improving the strength of the Brass texture and controlling the form of crystal grains, and finally has obviously faster alloy stress corrosion fracture time (43h) and general anti-spalling corrosion performance (EB).
The alloy of comparative example 2, although added with Sc and Zr elements, does not adopt two-stage homogenization, rapid extrusion forming and intermediate annealing process, only contains low strength Brass texture in the final alloy, and adopts single-stage peak aging treatment, and finally shows the worst corrosion resistance (stress corrosion cracking time: 23h, spalling corrosion sensitivity: EC).
Comparative example 3 the same deformation and heat treatment as in example 1, but with a higher Zr/SC weight ratio of the alloying element, Al is formed after homogenization of the alloy3(Sc1-x,Zrx) The particles have weak recrystallization inhibition capability, so that the final recrystallization degree of the alloy is higher, the Brass texture strength is lower, the fiber crystal proportion is smaller, and the corrosion resistance performance is poorer (stress corrosion fracture time: 45h, exfoliation corrosion susceptibility: EB).
Comparative example 4 the same deformation and heat treatment process as in example 1 was followed, but the weight comparison of the alloying elements Zr/SCSmall amount of Zr and Sc, and under the condition, Al formed by homogenizing the alloy3(Sc1-x,Zrx) Fewer particles have a weaker recrystallization inhibiting effect, thus resulting in a higher final recrystallization degree of the alloy, lower Brass texture strength, a smaller fiber-to-crystal ratio, and a poorer corrosion resistance (stress corrosion cracking time: 36h, exfoliation corrosion susceptibility: EB).
Comparative example 5 employs a higher temperature annealing process than example 1, which induces partial recrystallization, is disadvantageous to stabilization and improvement of Brass texture, and finally exhibits poor corrosion resistance (stress corrosion cracking time: 32h, exfoliation corrosion sensitivity: EC).
Comparative example 6 uses a lower extrusion rate deformation process than example 1, the low rate extrusion deformation process favours the occurrence of dynamic recrystallization, reduces the Brass texture strength and results in a smaller crystal fraction of the final alloy fibre, the alloy exhibiting poorer corrosion resistance (stress corrosion cracking time: 30h, exfoliation corrosion susceptibility: EC).
The test results in table 1 show that the preparation method provided by the embodiment of the present invention achieves the purpose of improving the mechanical strength of the alloy on the premise of ensuring the corrosion performance through the improvement of the composition and the matching process.
Test example 2
The metallographic structure of the wall thickness section of the alloy thin-walled extrusion obtained in example 1 was measured, and the results are shown in fig. 1; the gold phase diagram of the wall thickness section of the alloy thin-walled extrusion obtained in comparative example 1 was tested, and the result is shown in fig. 2.
As can be seen from a comparison of fig. 1 and 2, the crystal grain morphology of example 1 is mainly the elongated fiber morphology, and the crystal grain morphology of comparative example 2 is mainly the equiaxed or nearly equiaxed morphology.
In conclusion, according to the preparation method of the corrosion-resistant Al-Zn-Mg-Cu alloy, a proper amount of Zr, Sc and other elements are added into the Al-Zn-Mg-Cu alloy, and the processes of two-stage homogenization, deformation processing, intermediate annealing, solution quenching and regression re-aging treatment are matched, so that the formation of a high-strength Brass texture is promoted, the stress corrosion resistance and the spalling corrosion resistance of the Al-Zn-Mg-Cu alloy are greatly improved, and the high tensile strength is kept. Can be used for preparing aviation components, automobiles, rail transit or marine ships and has good industrial application prospect.
The embodiments described above are some, but not all embodiments of the invention. The detailed description of the embodiments of the present invention is not intended to limit the scope of the invention as claimed, but is merely representative of selected embodiments of the invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
Claims (12)
1. A preparation method of corrosion-resistant Al-Zn-Mg-Cu alloy is characterized by comprising the steps of smelting raw materials to form an alloy ingot, and sequentially carrying out two-stage homogenization, deformation processing, intermediate annealing, solution quenching and regression re-aging treatment;
the raw materials are proportioned according to the following alloy compositions in percentage by weight: 7.5 to 8.3 percent of Zn, 1.6 to 2.0 percent of Mg, 1.8 to 2.2 percent of Cu, 0.01 to 0.05 percent of Mn, 0.03 to 0.18 percent of Zr, 0.01 to 0.05 percent of Sc, less than or equal to 0.05 percent of Fe, less than or equal to 0.05 percent of Si, and the balance of Al, wherein the weight ratio of Zr to Sc is 2.0 to 3.5;
the operation temperature of the intermediate annealing process is controlled to be 280-320 ℃, and the operation time is 1.5-4 h;
the orientation strength of the Brass texture of the alloy matrix is not less than 15, and the proportion of the fiber form crystal grains is not less than 70%.
2. The method of claim 1, wherein the alloy comprises, in weight percent: 7.8 to 8.1 percent of Zn, 1.8 to 2.0 percent of Mg, 1.9 to 2.1 percent of Cu, 0.02 to 0.04 percent of Mn, 0.13 to 0.18 percent of Zr, 0.03 to 0.04 percent of Sc, less than or equal to 0.05 percent of Fe, less than or equal to 0.05 percent of Si, and the balance of Al, wherein the weight ratio of Zr to Sc is 2.6 to 3.0.
3. The method as claimed in claim 1, wherein the two-stage homogenization comprises a first-stage homogenization treatment and a second-stage homogenization treatment, the treatment temperature of the first-stage homogenization treatment is 365-390 ℃, and the treatment temperature of the second-stage homogenization treatment is 465-472 ℃.
4. The preparation method according to claim 3, wherein the treatment time of the first-stage homogenization treatment is 3-6h, and the treatment time of the second-stage homogenization treatment is 12-24 h.
5. The preparation method according to claim 1, wherein the deformation processing adopts an extrusion deformation method, and a thin-wall section with the thickness of 3-18mm is formed after the extrusion deformation is controlled.
6. The preparation method according to claim 5, wherein the extrusion deformation is performed by means of rapid extrusion, and the extrusion speed is controlled to be greater than or equal to 4.5 m/min.
7. The method as claimed in claim 6, wherein the extrusion temperature of the billet is controlled to 390-420 ℃ and the extrusion ratio is greater than or equal to 25 during the rapid extrusion process.
8. The preparation method as claimed in claim 1, wherein the solution quenching is solution treatment at 465-475 ℃ for 20-75min, and then quenching cooling.
9. The production method according to claim 8, wherein the quenching cooling is cooling to room temperature in water.
10. The preparation method according to claim 1, wherein the regression and reaging comprises three stages of primary reaging, secondary regression and tertiary reaging, the treatment temperature of the primary reaging is 105-120 ℃, and the treatment time is 20-30 h; the treatment temperature of the second-stage regression is 175-190 ℃, and the treatment time is 6-20 min; the treatment temperature of the third-stage re-aging is 105-120 ℃, and the treatment time is 20-30 h.
11. A corrosion-resistant Al-Zn-Mg-Cu alloy, characterized by being produced by the production method of any one of claims 1 to 10.
12. Use of the corrosion resistant Al-Zn-Mg-Cu alloy according to claim 11 for the manufacture of aeronautical components, automobiles, rail transit or marine vessels.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110044558.XA CN112877624B (en) | 2021-01-13 | 2021-01-13 | Corrosion-resistant Al-Zn-Mg-Cu alloy, and preparation method and application thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110044558.XA CN112877624B (en) | 2021-01-13 | 2021-01-13 | Corrosion-resistant Al-Zn-Mg-Cu alloy, and preparation method and application thereof |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN112877624A CN112877624A (en) | 2021-06-01 |
| CN112877624B true CN112877624B (en) | 2022-01-18 |
Family
ID=76045714
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202110044558.XA Active CN112877624B (en) | 2021-01-13 | 2021-01-13 | Corrosion-resistant Al-Zn-Mg-Cu alloy, and preparation method and application thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN112877624B (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114855013B (en) * | 2022-05-30 | 2023-02-28 | 栋梁铝业有限公司 | Method for quickly extruding and forming aluminum alloy at low temperature and application thereof |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5226983A (en) * | 1985-07-08 | 1993-07-13 | Allied-Signal Inc. | High strength, ductile, low density aluminum alloys and process for making same |
| CN105506521A (en) * | 2015-12-14 | 2016-04-20 | 湖南科技大学 | Treatment method for brass texture antifatigue aluminum alloy panel |
| CN107190186A (en) * | 2017-05-31 | 2017-09-22 | 佛山科学技术学院 | A kind of novel ultra-high-strength/tenacity aluminum alloy and preparation method thereof |
| CN108103373A (en) * | 2017-12-28 | 2018-06-01 | 中南大学 | A kind of argentiferous Al-Cu-Mg alloy and the heat treatment method for obtaining high intensity P texture |
| CN108385003A (en) * | 2018-05-23 | 2018-08-10 | 东北轻合金有限责任公司 | A kind of aerospace high-ductility corrosion aluminium alloy extrusions and preparation method thereof |
| CN110184513A (en) * | 2019-07-03 | 2019-08-30 | 广西南南铝加工有限公司 | High anti-stress-corrosion Al-Zn-Mg-Cu aluminium alloy extrusions and preparation method thereof |
Family Cites Families (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US7182823B2 (en) * | 2002-07-05 | 2007-02-27 | Olin Corporation | Copper alloy containing cobalt, nickel and silicon |
| US20190169727A1 (en) * | 2017-12-04 | 2019-06-06 | Kaiser Aluminum Fabricated Products, Llc | Low Cost, Substantially Zr-Free Aluminum-Lithium Alloy for Thin Sheet Product with High Formability |
| CN111549264B (en) * | 2020-06-17 | 2021-11-02 | 中铝萨帕特种铝材（重庆）有限公司 | Preparation process of high-strength corrosion-resistant 5383 aluminum alloy and marine section |
| CN112195424A (en) * | 2020-10-29 | 2021-01-08 | 天津忠旺铝业有限公司 | Preparation process for improving r value and uniformity of 6016 aluminum alloy plate |
-
2021
- 2021-01-13 CN CN202110044558.XA patent/CN112877624B/en active Active
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5226983A (en) * | 1985-07-08 | 1993-07-13 | Allied-Signal Inc. | High strength, ductile, low density aluminum alloys and process for making same |
| CN105506521A (en) * | 2015-12-14 | 2016-04-20 | 湖南科技大学 | Treatment method for brass texture antifatigue aluminum alloy panel |
| CN107190186A (en) * | 2017-05-31 | 2017-09-22 | 佛山科学技术学院 | A kind of novel ultra-high-strength/tenacity aluminum alloy and preparation method thereof |
| CN108103373A (en) * | 2017-12-28 | 2018-06-01 | 中南大学 | A kind of argentiferous Al-Cu-Mg alloy and the heat treatment method for obtaining high intensity P texture |
| CN108385003A (en) * | 2018-05-23 | 2018-08-10 | 东北轻合金有限责任公司 | A kind of aerospace high-ductility corrosion aluminium alloy extrusions and preparation method thereof |
| CN110184513A (en) * | 2019-07-03 | 2019-08-30 | 广西南南铝加工有限公司 | High anti-stress-corrosion Al-Zn-Mg-Cu aluminium alloy extrusions and preparation method thereof |
Non-Patent Citations (1)
| Title |
|---|
| "新型高强铝合金高温平面压缩与退火";路瑞龙，等;《稀有金属材料与工程》;20151231;第44卷(第12期);第3094-3098页 * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN112877624A (en) | 2021-06-01 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US11851739B2 (en) | High-strength magnesium alloy profile, preparation process therefor and use thereof | |
| EP0157600A2 (en) | Aluminum lithium alloys | |
| CN109182857B (en) | High-strength and high-toughness deformed magnesium alloy and preparation method thereof | |
| CN109182809B (en) | Low-cost high-toughness wrought magnesium alloy and preparation method thereof | |
| CN111270115A (en) | Method for manufacturing high-strength 7000 series aluminum alloy section for automobile body | |
| CN110983125A (en) | 6-series aluminum alloy template and production process thereof | |
| EP0325937B1 (en) | Aluminum-lithium alloys | |
| CN112877624B (en) | Corrosion-resistant Al-Zn-Mg-Cu alloy, and preparation method and application thereof | |
| CN108118206A (en) | Aluminum alloy plate materials and its manufacturing method with high natrual ageing stability and high baking hardenability | |
| CN111304502A (en) | High-strength 7000 series aluminum alloy section for automobile body and manufacturing method | |
| CN109234592B (en) | Low-temperature rolled high-strength-toughness wrought magnesium alloy and preparation method thereof | |
| CN112322949B (en) | Magnesium alloy material, and part and device comprising same | |
| CN112481536B (en) | Magnesium alloy thick plate and preparation method thereof | |
| CN115786788B (en) | Heat-resistant corrosion-resistant Al-Cu-Mg alloy and preparation method and application thereof | |
| WO2019163161A1 (en) | Magnesium alloy and method for producing magnesium alloy | |
| CN105525176A (en) | Preparation and treatment process of Mg-Gd-Y-Zr alloy | |
| JP3834076B2 (en) | Extruded material manufacturing method | |
| CN110408868B (en) | Preparation method of aging-free high-strength and high-toughness aluminum alloy based on large deformation homogenization | |
| CN112442618B (en) | Novel Al-Mg-Si aluminum alloy energy-absorbing material for collision and preparation method thereof | |
| CN115261649A (en) | High-performance low-carbon secondary aluminum extruded section and preparation method thereof | |
| CN108559898B (en) | Low-cost high-toughness wrought magnesium alloy and preparation method thereof | |
| WO2021003528A1 (en) | Aluminium alloys | |
| JP2019183264A (en) | High strength aluminum alloy, aluminum alloy sheet and aluminum alloy member using the aluminum alloy | |
| CN115821136B (en) | Low-alloy-content high-strength plastic magnesium alloy and preparation method thereof | |
| CN113667870B (en) | High-stress corrosion resistant aluminum-copper-lithium alloy material |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant | ||
| TR01 | Transfer of patent right |
Effective date of registration: 20221117 Address after: 510000 363 Changxin Road, Tianhe District, Guangzhou, Guangdong. Patentee after: Institute of new materials, Guangdong Academy of Sciences Address before: 510000 363 Changxin Road, Tianhe District, Guangzhou, Guangdong. Patentee before: Institute of materials and processing, Guangdong Academy of Sciences |
|
| TR01 | Transfer of patent right |