CN-122007150-A - High-strength large-difference-thickness-ratio aluminum alloy thick plate and preparation method and application thereof

Abstract

The invention discloses a high-strength large-difference-thickness-ratio aluminum alloy thick plate and a preparation method and application thereof, and belongs to the technical field of rolling. The preparation method comprises the steps of carrying out first-pass variable thickness rolling on thick plates such as T6-state aluminum alloy with the thickness of 2.5mm on a cold rolling mill, dynamically adjusting roll gaps in real time to obtain aluminum alloy differential thick plates with the thicknesses of 1.1mm and 2.4mm in a thin area and a thick area respectively, carrying out solution treatment and pre-ageing treatment, carrying out second-pass variable thickness rolling on the pre-ageing treated aluminum alloy differential thick plates, dynamically adjusting the rolls in real time to obtain aluminum alloy differential thick plates with the thicknesses of 1.0mm and 2.3mm in the thin area and the thick area respectively, and sequentially carrying out re-ageing treatment, pre-stretching strain treatment and simulated paint baking hardening treatment. The tensile strength is 370-410 MPa, the elongation after break is 14-21%, the strength is high, the plasticity is excellent, the thickness difference ratio is large, and the structural dead weight of automobile parts can be obviously reduced.

Inventors

• ZHI YING
• SUN TAO
• HU XIANLEI
• LIU XIANGHUA

Assignees

• 东北大学

Dates

Publication Date

20260512

Application Date

20260226

Claims (10)

1. 1. The preparation method of the high-strength large-difference-thickness-ratio aluminum alloy thick plate is characterized by comprising the following steps of: first-pass variable thickness rolling: rolling a T6-state aluminum alloy equal-thickness plate with the thickness of 2.5mm on a cold rolling mill for the first time, dynamically adjusting the roll gap in real time, rolling the aluminum alloy equal-thickness plate into an aluminum alloy differential-thickness plate, wherein the thicknesses of a thin area and a thick area are respectively 1.1mm and 2.4mm, and the curve of a transition area is in straight line leading transition; Solution treatment: carrying out solution treatment on the aluminum alloy differential thick plate obtained by the first-time variable thickness rolling; pre-ageing: Carrying out pre-aging treatment on the aluminum alloy differential thick plate subjected to solution treatment; And (3) rolling in a second pass: Performing second-pass variable thickness rolling on the pre-ageing-treated aluminum alloy differential thick plate on a cold rolling mill, and dynamically adjusting a roll gap in real time to obtain the second-pass variable thickness-rolled aluminum alloy differential thick plate, wherein the thicknesses of a thin area and a thick area are respectively 1.0mm and 2.3mm, the differential thickness ratio is 1:2.3, and a transition area curve is a linear leading transition; And (3) re-aging: Carrying out re-aging treatment on the aluminum alloy differential thick plate after the second pass rolling; And (3) prestretching strain treatment: pre-stretching strain simulation stamping forming is carried out on the re-aged aluminum alloy differential thick plate; and (3) simulating baking varnish hardening treatment: And (3) performing simulated baking varnish hardening treatment on the prestretched and strained aluminum alloy differential thick plate to obtain the high-strength large-differential-thickness-ratio aluminum alloy differential thick plate.
2. 2. The method for producing a high-strength large-gauge-ratio aluminum alloy gauge plate according to claim 1, wherein in the first pass of variable gauge rolling, the aluminum alloy gauge plate comprises, in mass percent, ：Mg：1.12%-1.15%,Si：0.70%-0.75%,Mn：0.10%-0.12%,Cu：0.19%-0.21%,Ti：0.03%-0.04%,Zn：0.09%-0.10%,Cr：0.08%-0.09%,Fe：0.50%-0.55%, of the following components, the balance being Al.
3. 3. The method for producing a high-strength large-difference-to-thickness-ratio aluminum alloy differential thick plate according to claim 1, wherein in the solid solution treatment, the solid solution temperature is 540 ℃ to 550 ℃ and the solid solution time is 10min to 30min.
4. 4. The method for producing a high strength large difference to thickness ratio aluminum alloy differential thickness plate according to claim 1, wherein in the pre-aging treatment, the pre-aging temperature is 120 ℃ to 130 ℃ and the pre-aging time is 1h to 3h.
5. 5. The method for producing a high strength large gauge thick plate of aluminum alloy as claimed in claim 1, wherein the re-aging temperature is 120 ℃ to 130 ℃ and the re-aging time is 1h to 5h.
6. 6. The method for producing a high strength large differential thickness ratio aluminum alloy differential thickness plate according to claim 1, wherein the amount of the pre-stretching strain in the pre-stretching strain treatment is 2% -3%.
7. 7. The method for producing a high-strength large-difference-thickness-ratio aluminum alloy differential thick plate according to claim 1, wherein in the simulated paint baking hardening treatment, the paint baking hardening temperature is 170-180 ℃, and the heating and heat-preserving time is 25-35 min.
8. 8. The high-strength large-difference-thickness-ratio aluminum alloy thick plate is characterized by being prepared by adopting the preparation method of the high-strength large-difference-thickness-ratio aluminum alloy thick plate in any one of claims 1-7.
9. 9. The high strength large gauge thickness ratio aluminum alloy gauge plate of claim 8, wherein the high strength large gauge thickness ratio aluminum alloy gauge thickness zone has a thickness of 2.3mm, the thin zone has a thickness of 1.0mm, the gauge ratio is 1:2.3, and the transition zone has a transition zone with a curve of straight dominant transition, a tensile strength of 370MPa-410MPa, and an elongation after break of 14% -21%.
10. 10. Use of the high strength high gauge thick plate of aluminum alloy of claim 8 in automotive manufacturing.

Description

High-strength large-difference-thickness-ratio aluminum alloy thick plate and preparation method and application thereof Technical Field The invention belongs to the technical field of rolling, and particularly relates to a high-strength large-difference-thickness-ratio aluminum alloy thick plate, a preparation method and application thereof. Background The cold-rolled differential thick plate has been widely applied to industries such as automobiles, shipbuilding, bridges and the like, and has the core advantages of saving materials, reducing weight, reducing the number of welding seams, controlling the production cost, improving the production efficiency and the like. The structural characteristics of the sheet material are quite definite, and the sheet material comprises a thin area, a thick area and a transition area for connecting the thin area and the thick area. Compared with a laser splice welding plate, the cold-rolled differential thick plate has the characteristics of more product quality assurance, low production cost and high production efficiency due to a weld-free structure. More importantly, the shape parameters such as the length, the slope and the like of the transition area can be customized and designed according to the stress distribution rule of the stamping part in the actual service process, so that the material thickness can be distributed according to the need, the material efficiency can be exerted to the maximum extent, the material is the preferred material in the field of automobile light weight by virtue of the more excellent material saving and weight reduction effects, and the material is gradually the focus of attention of the industry. At present, the differential thick plate technology is successfully applied to the production and manufacture of light-weight parts of domestic and foreign automobiles, and can be used for processing various key parts such as a B column, an anti-collision beam, a front longitudinal beam and the like, wherein the application scene of the low alloy steel differential thick plate and the hot forming differential thick plate is most common, but the differential thick ratio is generally less than or equal to 1:2. With the rapid development of the new energy automobile industry, the endurance mileage and the energy consumption efficiency become the core competition focus of the industry, and the weight reduction of the automobile body is one of the key paths for solving the problem. As a typical light material, the aluminum alloy has excellent characteristics of high strength, corrosion resistance, easy forming and the like, and can effectively reduce the weight of a vehicle body when being applied to a new energy automobile body and a chassis part, thereby reducing the load of a power system and realizing the dual aims of energy consumption reduction and power performance improvement. In recent years, the application ratio of aluminum alloy in automobile bodies and chassis parts is continuously increased, and compared with the traditional steel plate body, the weight reduction effect of the aluminum alloy body is more remarkable. The variable-thickness rolling technology and the aluminum alloy material are organically fused, and the research and development of the high-strength aluminum alloy differential thick plate is hopeful to further promote the iterative upgrade of the automobile light-weight technology. From application prospect analysis, compared with the traditional equal-thickness aluminum alloy parts, the aluminum alloy differential plate parts can achieve a weight reduction effect of 20% -30%, the material utilization rate can be improved to above 60%, and the aluminum alloy differential plate parts are suitable for the core fields of covering automobile chassis components, cross beams, automobile door components, seat components, automobile body structural components and the like. At present, the industrial mass production of the aluminum alloy differential thick plate is not realized yet, and particularly, the related research of the preparation process of the high-strength aluminum alloy differential thick plate with the differential thickness ratio larger than 1:2 is still in an exploration stage, and the systematic and deep technical accumulation is lacked. Under the background, development and application of the high-strength large-difference-thickness-ratio aluminum alloy thick plate for the automobile are developed, and the method is a new energy-saving and material-saving technical direction with technical characteristics and application value. The breakthrough of the technology not only can provide a better and light-weight solution for the new energy automobile industry, but also has extremely high practical application value and wide market popularization prospect. Disclosure of Invention Aiming at the problems existing in the prior art, the invention aims to provide the high-strength large-difference-thickness-ratio alumi