(1. 蘭州理工大學(xué) 省部共建有色金屬先進(jìn)加工與再利用國(guó)家重點(diǎn)實(shí)驗(yàn)室，蘭州 730050;
2. 西安航空職業(yè)技術(shù)學(xué)院 航空材料工程學(xué)院，西安 710089)
摘 要: 采用脈沖旁路耦合電弧MIG熔釬焊方法用4043鋁合金焊絲對(duì)1060鋁合金/鍍鋅鋼異種金屬進(jìn)行搭接焊;350 ℃下對(duì)鋁/鋼焊接接頭進(jìn)行退火處理，通過(guò)面掃描對(duì)退火前后焊接接頭焊縫中合金元素的分布進(jìn)行對(duì)比分析，用浸泡法和電化學(xué)法對(duì)退火前后焊接接頭的腐蝕行為進(jìn)行研究，分析焊接接頭不同區(qū)域的腐蝕行為及退火熱處理對(duì)焊接接頭腐蝕性能的影響。結(jié)果表明:焊接接頭退火熱處理后，其焊縫中的合金元素Si發(fā)生均勻化擴(kuò)散，同時(shí)，富鋅區(qū)界面反應(yīng)層的金屬間化合物Fe2Al5Zn0.4明顯變厚;腐蝕試驗(yàn)表明鋁/鋼熔釬焊焊接接頭發(fā)生電偶腐蝕，其鋼側(cè)被嚴(yán)重腐蝕，而焊縫側(cè)僅發(fā)生輕微的腐蝕，界面反應(yīng)層金屬間化合物的存在對(duì)接頭的腐蝕性能是不利的;除此之外還發(fā)現(xiàn)焊接接頭富鋅區(qū)的腐蝕電位較低，最易發(fā)生腐蝕;在此基礎(chǔ)上通過(guò)面掃描對(duì)富鋅區(qū)的腐蝕行為進(jìn)行進(jìn)一步的分析。
關(guān)鍵字: 鋁/鋼熔釬焊;電偶腐蝕;金屬間化合物;富鋅區(qū)
（1. State Key Laboratory of Advanced Processing and Recycling of Nonferrous Metals,
Lanzhou University of Technology, Lanzhou 730050, China;
2. School of Aeronautical Materials Engineering, Xi’an Aeronautical Polytechnic Institute, Xi’an 710089, China）
Abstract:The dissimilar metals of 1060 aluminum alloy and galvanized steel were joined with lap joint by pulsed double electrode gas metal arc welding-brazing with 4043 aluminum filler metal. The welding joints of aluminum and steel were then annealed at 350 ℃. The distribution of alloy elements in the welding joint different zones before and after annealing treatment was analyzed by map scanning, and the corrosion behavior of the welding joints was investigated by immersion corrosion tests and electrochemical corrosion tests, the corrosion behavior of the welding joints different zones and the effects of annealing treatment on corrosion property of welding joint were analyzed. The results show that the homogenization diffusion of Si elements in weld seam occurs after annealing treatment, meanwhile, the thickness of Fe2Al5Zn0.4 of zinc-rich zone increases significantly. In addition, the galvanic corrosion occurs when the samples are immersed in corrosive media, the whole steel of welding joint is corroded drastically and displays a homogeneous corrosion, however, the dissolution of weld seam is slight. The intermetallic phases at the interface reduces the corrosion property of welding joints. Further, the results indicate that zinc-rich zone of weld joints is most prone to corrosion. The corrosion behavior of zinc-rich zone was analyzed by map scanning on the basis of the test results.
Key words: aluminum-steel welding-brazing; galvanic corrosion; intermetallic compounds; zinc-rich zone
