摘要
采用显微硬度及电导率测试,剥落腐蚀及电化学腐蚀试验,光学显微镜(OM)及透射电镜(TEM),研究经ER5356焊丝钨极氩弧焊(TIG)的7003铝合金型材焊接接头各部分的微观组织与性能。结果表明:在离焊缝中心30 mm左右的热影响区位置形成硬度较低的软化区,这是由于η′(Mg Zn2)相的长大粗化;焊接接头的耐蚀性依次为焊缝区>过时效区>母材区>淬火区,其原因是淬火区的晶界析出相连续分布,形成连续阳极腐蚀通道,增大了应力腐蚀及剥落腐蚀倾向,使得腐蚀性能很差;而过时效区和母材区的晶界析出相不连续,耐蚀性较好。
The properties and microstructure of the different welded Joint zone of 7003 aluminum ahoy welded using 5356 welding wire by the method of TIG welding were researched by OM, TEM, vikers hardness and conduction test, exfloliation and electrochemical corrosion experiment. The results show that the heat affected zone, approximately 30 mm away from the centre of welding seam, is the soften zone as a result of η＇（MgZn2） coarsening. The corrosion resistance of TIG welded joint are ,in order, Welded zone 〉 Overaging zone 〉 Base metal〉 Quenching zone. Because the precipitates from grain are continuous in quenching zone, which forms the continuous anode corrosion channel that increases the tendency of stress corrosion cracking and exfloliation corrosion, quenching zone has poor corrosion resistance. However,the precipitates from grain are discontinuous in overaging zone and base metal, which makes the overaging zone and base metal have a higher corrosion resistance.
出处
《粉末冶金材料科学与工程》
EI
北大核心
2016年第6期832-839,共8页
Materials Science and Engineering of Powder Metallurgy
基金
国家重点基础研究计划资助项目(2012CB619502
2010CB731701)
湖南省自然科学基金(12JJ6040)
国家自然科学基金(51201186)
国家重大科研仪器设备研制专项(51327902)
关键词
7003铝合金
TIG焊
剥落腐蚀
电化学腐蚀
显微组织
7003 alloy
tungsten inert gas arc welding
exfloliation corrosion
electrochemical corrosion
microstructure
