回归冷却速率对Al-Zn-Mg-Cu合金型材组织与性能的影响  

Effect of Retrogression with Different Cooling Rates on Microstructure and Properties of Al⁃Zn⁃Mg⁃Cu Alloy Profiles

作　　者：关悦 高靖靖 胡庆宽 郑鹏辉 柯书忠 贺春花 叶凌英[2] GUAN Yue;GAO Jingjing;HU Qingkuan;ZHENG Penghui;KE Shuzhong;HE Chunhua;YE Lingying(Henan Key Laboratory of Fastening Connection Technology,Xinyang 464000,Henan,China;School of Material Science and Engineering,Central South University,Changsha 410083,Hunan,China)

机构地区：[1]河南省紧固连接技术重点实验室,河南信阳464000 [2]中南大学材料科学与工程学院,湖南长沙410083

出　　处：《矿冶工程》2023年第3期140-144,共5页Mining and Metallurgical Engineering

基　　金：国家重点研发计划(2022YFB3403700)。

摘　　要：通过硬度、电导率、室温拉伸、局部腐蚀和应力腐蚀等性能测试,结合金相显微镜和透射电镜等微观组织表征方法,研究了回归再时效工艺中不同回归冷却速率对Al-Zn-Mg-Cu合金型材组织与性能的影响。结果表明,回归冷却速率分别为660.0、12.7和0.5℃/min时,合金的抗拉强度分别为663.1、653.4和636.9 MPa,电导率分别为35.1%IACS、35.2%IACS和36.8%IACS,剥落腐蚀等级分别为EC、EB-和EB,应力腐蚀敏感性指数值分别为4.7%、4.0%和3.2%,晶界析出相沿长度方向的平均尺寸分别为48.7、54.7和68.7 nm,晶界析出相分布间距分别为28.9、33.6和40.3 nm。析出相尺寸与分布的变化是引起合金性能变化的主要原因;综合考虑合金力学性能与抗腐蚀性能,适宜的回归冷却速率范围为0.5~12.7℃/min。The effects of different cooling rates in retrogression and re⁃aging on the microstructure and properties of Al⁃Zn⁃Mg⁃Cu alloy profiles were investigated by performing tests on hardness,electrical conductivity,room temperature tensile,local corrosion and stress corrosion,combined with microstructure characterization by using metallographic microscopy and transmission electron microscopy.The results show that retrogression with cooling rates of 660.0,12.7 and 0.5℃/min,the alloy has a tensile strength of 663.1,653.4 and 636.9 MPa,an electrical conductivity of 35.1%IACS、35.2%IACS and 36.8%IACS,an exfoliation corrosion in the form of EC,EB-and EB,and a stress corrosion sensitivity of 4.7%,4.0%and 3.2%,respectively.The precipitates at grain boundaries along the direction of length,with an average size of 48.7,54.7 and 68.7 nm,are distributed with a spacing of 28.9,33.6 and 40.3 nm,respectively.The variation in size and distribution is the main reason for variation of the above⁃mentioned properties.With both mechanical properties and corrosion resistance taken into consideration,it is appropriate to select cooling rates ranging from 0.5℃/min to 12.7℃/min for retrogression.

关 键 词：Al-Zn-Mg-Cu合金 回归冷却速率 力学性能 抗腐蚀性能 应力腐蚀 剥落腐蚀 晶界析出相 微观组织 回归再时效 

分 类 号：TG139[一般工业技术—材料科学与工程]