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CN-121992229-A - Preparation method of 6110A aluminum alloy bar for automobile forging

CN121992229ACN 121992229 ACN121992229 ACN 121992229ACN-121992229-A

Abstract

The invention discloses a preparation method of a 6110A aluminum alloy bar for automobile forging, and belongs to the field of aluminum alloy bar processing. The method comprises the steps of heating a pure aluminum ingot to 720-740 ℃ for melting, then uniformly dispersing and putting an intermediate alloy into a smelting furnace at a nine-grid position, stirring, refining, degassing, filtering and casting to obtain an aluminum alloy ingot, performing three-stage homogenization treatment on the ingot, performing low-temperature extrusion on the homogenized ingot, performing online solution treatment on the extruded bar, performing spray quenching, and performing aging treatment after quenching. According to the invention, the grain size grade of the prepared aluminum alloy bar can reach more than 7 grades by adopting nine-palace-shaped input intermediate alloy and combining a three-section homogenization process, and the low-temperature extrusion is adopted, and the temperature rising solution treatment is carried out after the extrusion, so that the thickness of a coarse crystal layer on the surface of the bar is less than 0.2mm, the heat energy consumption is reduced by about 30%, the tensile strength is more than or equal to 410 MPa, the yield strength is more than or equal to 385 MPa, and the elongation after fracture is more than or equal to 10%.

Inventors

  • Li Zhilue
  • PAN BAOWEN
  • XUE JIANXIN
  • WANG HAIDONG
  • HU ZHIJIAN

Assignees

  • 广西金铝金属制品有限公司

Dates

Publication Date
20260508
Application Date
20260224

Claims (7)

  1. 1. The preparation method of the 6110A aluminum alloy bar for the automobile forging is characterized by comprising the following components in percentage by weight: Si content is 0.75% -1.05%; the Mg content is 0.85% -1.15%; cu content is 0.25% -0.45%; mn content is 0.15% -0.35%; Zr content is 0.08% -0.18%; the Ti content is 0.04% -0.08%; fe content is less than or equal to 0.08%; cr content is less than or equal to 0.08%; the total content of other single impurity elements is less than or equal to 0.03 percent, and the balance is Al; the preparation method of the 6110A aluminum alloy bar for automobile forging comprises the following steps: ‌ S1, casting and online processing ‌, namely putting a pure aluminum ingot into a smelting furnace, heating to 720-740 ℃ to melt, putting alloy raw materials into the smelting furnace, and stirring, refining, degassing, filtering and casting to obtain an aluminum alloy ingot; ‌ S2, carrying out three-stage heating and three-stage room-temperature standing homogenization treatment on the cast ingot ‌; ‌ S3, extrusion forming and on-line solid solution aging ‌, namely heating the homogenized cast ingot to 390-410 ℃ for extrusion, carrying out on-line solid solution treatment on the extruded bar, quenching, and aging after quenching.
  2. 2. The method for preparing the 6110A aluminum alloy bar for automobile forging according to claim 1, wherein in the step S1, the charging port of the smelting furnace is divided into 9 parts according to the weight of the components, and each alloy raw material is evenly divided into 9 parts according to the weight of the components and mixed, and is put into the smelting furnace corresponding to the 9 parts.
  3. 3. The method for preparing the 6110A aluminum alloy bar for automobile forging according to claim 1, wherein in the step S2, the three-stage ingot homogenization treatment ‌ is specifically that the three-stage ingot is firstly heated to 300-320 ℃ at 100-120 ℃ per hour, then is parked at a furnace outlet room temperature for 8-10 hours after being kept at the temperature of 4-6 hours, then is parked at the furnace outlet room temperature for 8-10 hours after being heated to 420-440 ℃ at 130-150 ℃ per hour, finally is heated to 520-540 ℃ at the temperature of 6-8 hours at the temperature of 150-170 ℃ per hour, and then is slowly cooled to 200-220 ℃ at the speed of 80-100 ℃ per hour and then is cooled to the room temperature in an air.
  4. 4. The method for preparing the 6110A aluminum alloy bar for automobile forging according to claim 1, wherein in the step S3, the extruded bar is fed into an online solution furnace for solution treatment, the temperature of the bar at an inlet of the solution furnace is controlled to be 350-370 ℃, the temperature at an outlet of the solution furnace is controlled to be 540-560 ℃, and the time of the solution furnace is 8-10min.
  5. 5. The method for producing 6110A aluminum alloy bar for automobile forging according to claim 4, wherein the bar is subjected to spray quenching after solution treatment, and is subjected to aging treatment at 175 ℃ x 8h after spray quenching.
  6. 6. The method for producing 6110A aluminum alloy rod for automobile forging according to claim 1, wherein in step S3, the extrusion speed is 0.8 to 1m/min.
  7. 7. The method for producing 6110A aluminum alloy rod for automobile forging according to claim 1, wherein in step S3, the diameter of the rod is 80 to 100mm.

Description

Preparation method of 6110A aluminum alloy bar for automobile forging Technical Field The invention belongs to the field of aluminum alloy bar processing, and particularly relates to a preparation method of a 6110A aluminum alloy bar for automobile forging. Background With the deep trend of automobile light weight, aluminum alloy is increasingly widely applied to high-strength structural members such as automobile chassis, suspension systems and the like, such as control arms, steering knuckles and the like. The 6110A alloy is an ideal candidate material for the forging part of the automobile because of good strength, toughness and formability. However, in the existing production process of the 6110A aluminum alloy bar for automobile forging, grains are difficult to refine in the ‌ casting process, and in the casting process, as the aluminum intermediate alloy adopts centralized feeding, alloy elements are easily unevenly distributed in a melt to generate segregation, so that the grains are coarse and uneven, and the subsequent processing performance and the mechanical performance of a final product are affected. Therefore, there is a need to develop a production method capable of stabilizing fine grains, suppressing generation of coarse crystal layers, and achieving energy saving. Disclosure of Invention The invention aims to overcome the defects of the prior art and provides a preparation method of a 6110A aluminum alloy bar for automobile forging. The method realizes grain refinement, coarse grain layer control and energy saving and consumption reduction in the production process by optimizing the casting, homogenizing, extruding and heat treatment processes. In order to achieve the above purpose, the invention adopts the following technical scheme: The invention provides a preparation method of 6110A aluminum alloy bar for automobile forging, which comprises the following components in percentage by weight: Si content is 0.75% -1.05%; the Mg content is 0.85% -1.15%; cu content is 0.25% -0.45%; mn content is 0.15% -0.35%; Zr content is 0.08% -0.18%; the Ti content is 0.04% -0.08%; fe content is less than or equal to 0.08%; cr content is less than or equal to 0.08%; the total content of other single impurity elements is less than or equal to 0.03 percent, and the balance is Al; The preparation method of the 6110A aluminum alloy bar for automobile forging comprises the following steps: ‌ S1, casting and online processing ‌, namely putting a pure aluminum ingot into a smelting furnace, heating to 720-740 ℃ to melt, putting alloy raw materials into the smelting furnace, and stirring, refining, degassing, filtering and casting to obtain an aluminum alloy ingot; ‌ S2, carrying out three-stage heating and three-stage room-temperature standing homogenization treatment on the cast ingot ‌; ‌ S3, extrusion forming and on-line solid solution aging ‌, namely heating the homogenized cast ingot to 390-410 ℃ for extrusion, carrying out on-line solid solution treatment on the extruded bar, quenching, and aging after quenching. The addition of Cu can obviously reduce the quenching sensitivity of the alloy, so that the core part of the extrusion bar can form supersaturated solid solution during quenching, and the mechanical property of the extrusion bar is improved. Zr element is the core of the design, zr can form extremely fine nano particles with extremely high thermal stability in the casting and homogenizing process of extruded bars, and grain boundaries and subgrain boundaries can be strongly pinned in the heating process before extrusion and forging of the subsequent bars. Mn inhibits recrystallization and grain growth by forming a dispersed phase in cooperation with Zr. The Ti refines grains in the casting stage to obtain uniform and fine cast structure, and the macrosegregation is reduced. Fe is the most common detrimental impurity in aluminum alloys. The Fe content is strictly limited to be less than or equal to 0.08 percent and is far lower than the general standard. The aim is to minimize the formation of coarse needle-like phases and reduce the formation of microcrack sources. The deformation resistance of the metal can be reduced by adopting 390-410 ℃ low-temperature extrusion, the growth tendency of crystal grains is reduced, and the formation of a coarse crystal layer is effectively controlled. Meanwhile, the lower temperature can also improve the surface quality and the dimensional accuracy of the bar. As a further supplement of the scheme of the invention, the charging port of the smelting furnace is divided into 9 grids, each alloy raw material is evenly divided into 9 parts according to the weight of the components, and is mixed, and the alloy raw materials are charged into the smelting furnace at the position corresponding to the 9 grids, so that the phenomenon that the intermediate alloy is concentrated in a certain area to cause the overhigh or overlow local alloy components is avoided. As a further