6061/AZ31B异质板材搅拌摩擦焊缝的腐蚀特征  

Corrosion Characteristics of Friction Stir Welding Seams of 6061/AZ31B Heterogeneous Plates

作　　者：陈成 袁鸽成[1] 杨濂 林凌峰 CHEN Cheng;YUAN Gecheng;YANG Lian;LIN Lingfeng(School of Materials and Energy,Guangdong University of Technology,Guangzhou 510006,China)

机构地区：[1]广东工业大学材料与能源学院,广东广州510006

出　　处：《热加工工艺》2022年第11期32-36,42,共6页Hot Working Technology

基　　金：广东省自然科学基金项目(2014A030313518);广东省科技计划项目(2017A010103018)。

摘　　要：采用搅拌摩擦焊接法制备了6061/AZ31B异质合金板材的焊接样品。借助光学显微镜(OM)、扫描电子显微镜(SEM)、能谱仪(EDS)及X射线衍射仪(XRD)研究了接头焊缝至母材的组织特征,通过NaCl溶液浸泡腐蚀法和电化学腐蚀试验研究了焊缝与母材的腐蚀特征。结果表明,该焊缝铝侧组织较均匀,而焊缝镁侧形成富镁条带和富铝条带相间的不均匀带状组织。在腐蚀试验中,焊缝铝侧发生钝化,其耐蚀性优于铝母材,仅显现轻微的点蚀与晶间腐蚀行为;相对于镁母材,焊缝镁侧晶粒细化,提高了其耐蚀性,焊缝镁侧富镁带状区的腐蚀形貌与镁母材的相似,在合金表面形成了较明显的腐蚀产物及腐蚀裂纹,而富铝带状区仅产生了轻微的点蚀。The welded samples of 6061/AZ31B heterogeneous alloy plates were prepared by friction stir welding. With the help of OM, SEM, EDS and XRD, the microstructure of the welded joint from the weld to the base metal were studied.The corrosion characteristics of the weld and base metals were studied by the NaCl solution immersion corrosion method and electrochemical corrosion tests. The results show that the structure of the weld at aluminum side is relatively uniform, while non-uniform band-like structure composed of magnesium-rich and aluminum-rich bands is formed in the weld at the magnesium side. In the corrosion test, the weld at the aluminum side is passivated, and its corrosion resistance is better than that of the aluminum base material, and only slight pitting and intergranular corrosion behaviors are shown. Compared with the magnesium base metal, the grain refinement of the weld at the magnesium side improves its corrosion resistance. The corrosion morphology of the magnesium-rich zone of the weld at the magnesium side is similar to that of the magnesium base material, obvious corrosion products and corrosion cracks are formed on the surface of the alloy. However, only slight pitting corrosion occurs in the aluminum-rich zone.

关 键 词：Al/Mg异质合金 搅拌摩擦焊 浸泡腐蚀 电化学腐蚀 

分 类 号：TG453.9[金属学及工艺—焊接] TG172