Al-Cu-Li合金电子束焊接头的耐蚀性能

Corrosion behavior of Al-Cu-Li alloy joint by electron beam welding

研究了新型Al-Cu-Li合金电子束焊接头的晶间腐蚀和剥落腐蚀行为。利用金相显微镜观察分析接头不同区域的晶间腐蚀IGC(Intergranular Corrosion)及剥蚀EXCO(Exfoliation Corrosion)形貌,并测量其最大晶间腐蚀深度。结果表明,在IGC溶液中浸泡24 h后,母材发生严重孔蚀,腐蚀深度较深;焊缝区发生局部网络状晶间腐蚀;热影响区观察到少量的晶间腐蚀现象。在EXCO溶液中浸泡96 h后,母材发生了严重剥落腐蚀,热影响区发生轻微的剥蚀,焊缝未发生剥蚀。

The intergranular corrosion（IGC）and exfoliation corrosion（EXCO）behavior of Al-Cu-Li alloy joints by electron beam welding are investigated. The morphologies of IGC and EXCO in different regions including base metal,heat-effected zone and weld metal are analyzed by using metallographic microscope respectively,and the maximum depth of intergranular corrosion is measured. Results indicate that,after joint sample is immersed in IGC solution for 24 h,great pitting corrosion occurs to base metal. The local intergranular corrosion occurs to weld metal and a little intergranular corrosion is developed within HAZ. After immersed in EXCO solution for 96 h,the base metal shows severe exfoliation corrosion,but weld metal is not susceptive to the exfoliation corrosion.