7N01 铝合金焊接接头腐蚀行为研究进展

Research Progress on Corrosion of 7N01 Aluminum AlloyWelded Joint

7N01铝合金在焊接时经历非均匀加热和冷却的过程,焊接接头的局部微观组织发生复杂变化,析出相产生不平衡的溶解及析出行为,并重新分配于界内及晶界,导致焊接接头各区域成分、组织相差较大,从而表现出不同的腐蚀敏感性。时效工艺、焊后处理、焊接工艺参数等一系列因素都会影响7N01铝合金焊接接头的耐蚀性能,同时,服役环境的复杂性也给7N01铝合金腐蚀行为的研究带来极大的挑战。综述7N01铝合金焊接接头的腐蚀类型、腐蚀研究方法、腐蚀发生区域,分析腐蚀机理及腐蚀影响因素,并探讨提升焊接接头耐腐蚀性能的主要途径。

7N01 aluminum alloy is a high-strength Al-Zn-Mg alloy with the advantages of heat-treatable strengthening,strong weldability,good processability and light weight.It has been widely used in high-speed trains,marine ships,aerospace and other fields.Since the 7N01 aluminum alloy welded joint has experienced the process of non-uniform heating and cooling,and the local microstructure of the welded joint has undergone complex changes.The precipitated phase has unbalanced dissolution and precipitation behavior,and is redistributed to the boundary and grain boundary,resulting in different components and structures in different regions of the welded joint,thus showing different corrosion sensitivity.A series of factors,such as aging process,post weld treatment and welding process parameters,will affect the corrosion resistance of 7N01 aluminum alloy welded joints.The complexity of service environment also brings great challenges to the research on corrosion behavior of 7N01 aluminum alloy.The corrosion types,research methods and occurrence areas of 7N01 aluminum alloy welded joints are reviewed.Meanwhile,the mechanism and influencing factors of corrosion resistance are analyzed,and the main ways to improve the corrosion resistance of the joints are proposed.