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CN-122012998-A - High-strength high-ductility aluminum alloy section bar and preparation method thereof

CN122012998ACN 122012998 ACN122012998 ACN 122012998ACN-122012998-A

Abstract

The invention relates to the field of aluminum alloy, and particularly discloses a high-strength high-ductility aluminum alloy section, which comprises, by mass, 0.35-0.75% of Si, less than or equal to 0.3% of Fe, less than or equal to 0.05% of Cu, 0.10-0.30% of Mn, 0.30-0.70% of Mg, less than or equal to 0.05% of Cr, less than or equal to 0.05% of Zn, less than or equal to 0.1% of Ti, less than or equal to 0.05% of other single trace alloy elements, less than or equal to 0.15% of other trace alloy elements in total, and the balance of Al. The technical scheme adopted by the invention has stable components, high dimensional accuracy and less surface defects.

Inventors

  • HU ZHONGHONG
  • WU XIAOBING
  • ZUO ZHENG

Assignees

  • 重庆海塑南邦铝业有限公司

Dates

Publication Date
20260512
Application Date
20260226

Claims (9)

  1. 1. The high-strength high-ductility aluminum alloy section comprises, by mass, 0.35-0.75% of Si, less than or equal to 0.3% of Fe, less than or equal to 0.05% of Cu, 0.10-0.30% of Mn, 0.30-0.70% of Mg, less than or equal to 0.05% of Cr, less than or equal to 0.05% of Zn, less than or equal to 0.1% of Ti, less than or equal to 0.05% of other single trace alloy elements, less than or equal to 0.15% of other trace alloy elements in total, and the balance of Al.
  2. 2. The high-strength high-ductility aluminum alloy section according to claim 1, wherein the mechanical properties of the aluminum alloy section meet that the tensile strength Rm is not less than 265N/mm2 and the specified non-proportional elongation strength Rp0.2 is not less than 245N/mm2.
  3. 3. The high-strength high-ductility aluminum alloy section according to claim 2, wherein the mechanical properties of the aluminum alloy section meet that the elongation after break A 50 is not less than 9% and the Webster hardness HW is not less than 14.
  4. 4. The high-strength high-ductility aluminum alloy section bar according to claim 3, wherein the aluminum alloy section bar is a penetrating strip type heat insulation section bar, and the room temperature longitudinal shearing resistance characteristic value and the room temperature transverse tensile characteristic value are both more than or equal to 24N/mm.
  5. 5. The high-strength high-ductility aluminum alloy section according to claim 4, wherein the room-temperature longitudinal shear characteristic value of the aluminum alloy section is not less than 40N/mm.
  6. 6. The preparation method of the high-strength high-ductility aluminum alloy section comprises the following steps: S1, preparing and casting raw materials, namely preparing an aluminum ingot, an intermediate alloy and trace alloy elements according to the component proportion of Si 0.35-0.75%, fe less than or equal to 0.3%, cu less than or equal to 0.05%, mn 0.10-0.30%, mg 0.30-0.70%, cr less than or equal to 0.05%, zn less than or equal to 0.05%, ti less than or equal to 0.1%, other single trace alloy elements less than or equal to 0.05% and the total of other trace alloy elements less than or equal to 0.15% in percentage by mass, and the balance of Al, putting the aluminum ingot into a smelting furnace, heating to 720-760 ℃ to melt, adding the intermediate alloy and the trace alloy elements, detecting the components by a spectrometer after refining and purifying treatment, adjusting the components to reach standards, and casting to obtain a casting rod; S2, extrusion molding, namely respectively heating a casting rod, an extrusion cylinder and a die, strictly controlling a three-temperature first-speed and three-point first-line production process, extrusion molding, quenching on line after extrusion, cooling to the surface temperature of less than or equal to 150 ℃, straightening, sawing, framing, hoisting the quenched profile into a time effect furnace, heating to 190-200 ℃, preserving heat for 2-4h, and discharging and air-cooling to room temperature; S3, surface treatment, namely sequentially performing water washing, oil removal, water washing, passivation, water washing, pure water washing, drying, spraying and curing treatment on the aged profile, wherein the spraying adopts a vertical powder spraying process, and the adhesion, hardness and film thickness of the coating are detected after curing; S4, deep processing and inspection, namely sequentially carrying out the steps of tooth forming, strip penetrating and rolling on the strip penetrating type heat insulation section, then carrying out finished product inspection according to the preset performance and size deviation requirements, and packaging and warehousing after the finished product is qualified.
  7. 7. The high strength and high ductility aluminum alloy section according to claim 6, wherein the refining and purifying treatment in S1 employs nitrogen degassing.
  8. 8. The high-strength high-ductility aluminum alloy section according to claim 7, wherein the smelting process in S1 adopts ultrasonic auxiliary treatment, the ultrasonic treatment is carried out for 6-10min when an aluminum ingot is smelted, the ultrasonic frequency is 16-20kHz, the ultrasonic intensity is 1.00-1.15kW/cm <2 >, the ultrasonic treatment is carried out for 8-15min after the aluminum ingot is mixed with intermediate alloy and other elements, and the ultrasonic parameters are consistent with the smelting stage.
  9. 9. The high-strength high-ductility aluminum alloy section according to claim 8, wherein the middle-high-glossiness powder-spraying section is polished or sand-blasted before spraying in the step S3, dust blowing or wiping treatment is carried out on the surface before upper discharge, the interval between the sections in the upper discharge process is more than or equal to 5cm, the friction caused by accumulation and backlog is prevented, and the curing treatment temperature is not lower than 190 ℃ for not lower than 10min.

Description

High-strength high-ductility aluminum alloy section bar and preparation method thereof Technical Field The invention relates to the field of aluminum alloy, in particular to a high-strength high-ductility aluminum alloy section bar and a preparation method thereof. Background The 6× aluminum alloy is widely used in the fields of automobiles, rail transit, engineering construction, and the like by virtue of its moderate strength, good workability and weldability. However, the prior art still has obvious defects in the aspects of considering the strength, the ductility, the dimensional accuracy and the production energy consumption of the aluminum alloy section. The existing aluminum alloy section is lack of accurate regulation and control in component design, the content of impurity elements is high, key links such as extrusion, heat treatment and surface treatment are not synergistically optimized, so that the product has insufficient dimensional accuracy and more surface defects, the requirements of severe dimensional tolerance and surface quality existing in automobile-level application cannot be met, and in addition, the indexes such as the strength and the ductility of the existing section are difficult to meet the requirement of high-accuracy assembly. Therefore, there is an urgent need for a high-strength high-ductility aluminum alloy profile excellent in strength and ductility and a method for manufacturing the same. Disclosure of Invention The invention provides a high-strength high-ductility aluminum alloy section bar with stable components, high dimensional accuracy and few surface defects and a preparation method thereof. In order to solve the technical problems, the application provides the following technical scheme: The high-strength high-ductility aluminum alloy section comprises, by mass, 0.35-0.75% of Si, less than or equal to 0.3% of Fe, less than or equal to 0.05% of Cu, 0.10-0.30% of Mn, 0.30-0.70% of Mg, less than or equal to 0.05% of Cr, less than or equal to 0.05% of Zn, less than or equal to 0.1% of Ti, less than or equal to 0.05% of other single trace alloy elements, less than or equal to 0.15% of other trace alloy elements in total, and the balance of Al. Furthermore, the mechanical property of the aluminum alloy profile meets the requirements that the tensile strength Rm is more than or equal to 265N/mm < 2 >, the regulated non-proportional extension strength Rp0.2 is more than or equal to 245N/mm < 2 >, the elongation after break A50 is more than or equal to 9%, and the Webster hardness HW is more than or equal to 14. Further, the tensile strength Rm is more than or equal to 265N/mm2, and the non-proportional extension strength Rp0.2 is more than or equal to 245N/mm2. Furthermore, the aluminum alloy section is a penetrating strip type heat insulation section, and the room temperature longitudinal shearing resistance characteristic value and the room temperature transverse tensile characteristic value are both more than or equal to 24N/mm. Further, the room-temperature longitudinal shearing characteristic value of the aluminum alloy section is more than or equal to 40N/mm. The preparation method of the high-strength high-ductility aluminum alloy section comprises the following steps: S1, preparing and casting raw materials, namely preparing an aluminum ingot, an intermediate alloy and trace alloy elements according to the component proportion of Si 0.35-0.75%, fe less than or equal to 0.3%, cu less than or equal to 0.05%, mn 0.10-0.30%, mg 0.30-0.70%, cr less than or equal to 0.05%, zn less than or equal to 0.05%, ti less than or equal to 0.1%, other single trace alloy elements less than or equal to 0.05% and the total of other trace alloy elements less than or equal to 0.15% in percentage by mass, and the balance of Al, putting the aluminum ingot into a smelting furnace, heating to 720-760 ℃ to melt, adding the intermediate alloy and the trace alloy elements, detecting the components by a spectrometer after refining and purifying treatment, adjusting the components to reach standards, and casting to obtain a casting rod; S2, extrusion molding, namely respectively heating a casting rod, an extrusion cylinder and a die, strictly controlling a three-temperature first-speed and three-point first-line production process, extrusion molding, quenching on line after extrusion, cooling to the surface temperature of less than or equal to 150 ℃, straightening, sawing, framing, hoisting the quenched profile into a time effect furnace, heating to 190-200 ℃, preserving heat for 2-4 hours, discharging and cooling to room temperature; S3, surface treatment, namely sequentially performing water washing, oil removal, water washing, passivation, water washing, pure water washing, drying, spraying and curing treatment on the aged profile, wherein the spraying adopts a vertical powder spraying process, and the adhesion, hardness and film thickness of the coating are detected after curing; S4, deep pr