摘要
采用金相、硬度、电导率、剥落腐蚀、电化学腐蚀以及透射电镜(TEM)观察等分析测试方法研究焊后热处理对Al-Zn-Mg合金组织与性能的影响。结果表明:Al-Zn-Mg合金焊接接头固溶区的硬度和耐腐蚀性能随焊后热处理时效时间的延长和温度的提高而提升。自然时效4 d+(130℃,24 h)和自然时效150 d+(150℃,2 h)两种焊后热处理工艺较佳:经自然时效4 d+(130℃,24 h)处理后,合金固溶区最大硬度由82.5HV提高至123HV,最大电导率由34%IACS提高至35.8%IACS,剥蚀等级提升至EA;经自然时效150 d+(150℃,2 h)处理后,合金固溶区最大硬度提高至110HV,最大电导率至34.7%IACS,剥蚀等级提升至N。合金焊接接头固溶区硬度与耐腐蚀性能提升的主要原因是焊后时效热处理促进焊接固溶区晶内析出相粗化,弥散分布,且晶界析出相呈不连续分布状。
The effects of post-welding heat treatment on microstructure and properties of Al-Zn-Mg alloy welded joint were studied by optical microstructure, hardness, conductivity, exfoliation corrosion testing, electrochemical corrosion testing and transmission electron microscopy（TEM） testing. The results show that the hardness and corrosion resistance of welded joint at solid solution zone of Al-Zn-Mg alloy increase with post-welding aging time and temperature increasing. Two kinds of optimum post-welding heat treatment to Al-Zn-Mg alloy are natural aging for 4 d＋artificial aging at（130 ℃, 24 h） and natural aging for 150 d＋artificial aging at（150 ℃, 2 h）. The maximum hardness of welded joint at solid solution zone of Al-Zn-Mg alloy increases from 82.5 HV to 123 HV, the maximum conductivity increases from 34%IACS to 35.8%IACS and the denudation level reaches to EA after natural aging 4 d＋artificial aging at（130 ℃, 24 h） treatment. The maximum hardness of welded joint at solid solution zone of Al-Zn-Mg alloy increases from 82.5 HV to 110 HV, the maximum conductivity increase from 34%IACS to 34.7%IACS and the denudation level reaches up to N after natural aging for 150 d＋artificial aging at（150 ℃, 2 h） treatment. The reason why aging treatment can improve the hardness and corrosion resistance of welded joint at solid solution zone of Al-Zn-Mg alloy is that the intragranular precipitate phase are coarsening and dispersion distribution, also the grain boundary precipitate phase distribution are discontinuous.
作者
杜春平
王培吉
DU Chun-pingl, WANG Pei-ji2＇ 3(1. Practical Teaching Department, Guilin University of Aerospace Technology, Guilin 541004, China; 2. Institute of Powder Metallurgy, Central South University, Changsha 410083, China; 3. Chengdu Beijing Oriental Electronics Optoelectronics Technology Co., Ltd., Chengdu 611731, Chin)
出处
《中国有色金属学报》
EI
CAS
CSCD
北大核心
2017年第12期2483-2492,共10页
The Chinese Journal of Nonferrous Metals
基金
广西教育厅科研项目(KY2015ZD141)~~
