金属热处理 ›› 2023, Vol. 48 ›› Issue (8): 161-165.DOI: 10.13251/j.issn.0254-6051.2023.08.026

• 工艺研究 • 上一篇    下一篇

退火工艺对7X50铝合金丝材组织与自然时效性能的影响

周泽宇1,3, 韩明明2, 肖翔1, 付金来2   

  1. 1.中铝材料应用研究院有限公司, 北京 102209;
    2.东北轻合金有限责任公司, 黑龙江 哈尔滨 150060;
    3.天津大学 材料科学与工程学院, 天津 300350
  • 收稿日期:2023-03-06 修回日期:2023-06-07 出版日期:2023-08-25 发布日期:2023-10-10
  • 通讯作者: 肖 翔,高级工程师,E-mail: xiang_xiao@chalco.com.cn
  • 作者简介:周泽宇(1991—),男,工程师,硕士,主要研究方向为先进铝合金材料制备及热处理工艺,E-mail: zeyuhello@foxmail.com。
  • 基金资助:
    XXX-2(TDGC-CL-20-020)

Effect of annealing process on microstructure and natural aged properties of 7X50 aluminum alloy wire

Zhou Zeyu1,3, Han Mingming2, Xiao Xiang1, Fu Jinlai2   

  1. 1. Chinalco Materials Application Research Institute Co., Ltd., Beijing 102209, China;
    2. Northeast Light Alloy Co., Ltd., Harbin Heilongjiang 150060, China;
    3. School of Materials Science and Engineering, Tianjin University, Tianjin 300350, China
  • Received:2023-03-06 Revised:2023-06-07 Online:2023-08-25 Published:2023-10-10

摘要: 7X50铝合金丝材在制备过程中通常经历中间退火-冷拉拔-冷镦等中间工艺过程,经单级退火后的丝材经常发生自然时效,强度上升,严重影响再次拉拔成型。采用光学显微镜、透射电镜、电子拉力试验机等手段对单级、双级中间退火后7X50铝合金丝材组织和性能进行分析。结果表明,丝材经404 ℃×2 h单级退火后组织发生部分再结晶,强度由退火前的235 MPa下降至188 MPa,并且在270 d停放后强度增加至244 MPa,发生明显自然时效硬化效应;丝材经404 ℃×2 h+233 ℃×4 h双级退火后,组织发生部分再结晶,强度下降至173 MPa,在270 d停放过程中不发生明显自然时效硬化效应。第二级233 ℃×4 h退火保温过程中促进了AlZnMgCu相和含Mg、Zn相析出和长大,消耗了大量Zn、Mg元素,有效消除了停放过程中的自然时效硬化效应。

关键词: 7X50铝合金丝材, 退火, 再结晶, 自然时效

Abstract: In the preparation process of 7X50 aluminum alloy wire, intermediate annealing-cold drawing-cold heading and other intermediate processes are required. After single-stage annealing, the wire often occurs natural aging and strength increases, which seriously affects the re-drawing forming. The microstructure and properties of the single-stage and double-stage intermediate annealed 7X50 aluminum alloy wires were analyzed by means of optical microscope, transmission electron microscope and electronic tensile testing machine. The results show that partial recrystallization occurs after single-stage annealing at 404 ℃ for 2 h, and the strength decreases from 235 MPa(before annealing) to 188 MPa, and increases to 244 MPa after placing for 270 d because of obvious natural aging effect. After double-stage annealing at 404 ℃ for 2 h and 233 ℃ for 4 h, partial recrystallization occurs and the strength decreases to 173 MPa, and no obvious natural aging hardening effect occurs during the 270 d placing. The second stage 233 ℃×4 h annealing holding process promotes the precipitation and growth of AlZnMgCu phases and Mg, Zn phases, which consumes a large amount of Zn, Mg elements, effectively eliminates the natural aging hardening effect during the process of placing.

Key words: 7X50 aluminum alloy wire, annealing, recrystallization, natural aging

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