Microstructure, Chemical Composition and Local Corrosion Behavior of a Friction Stud Welding Joint

作者:Ma, Huijuan*; Gu, Yanhong; Gao, Hui; Jiao, Xiangdong; Che, Juntie; Zeng, Qunfeng
来源:Journal of Materials Engineering and Performance, 2018, 27(2): 666-676.
DOI:10.1007/s11665-018-3182-4

摘要

In this paper, friction stud welding technology was used to join a stud and base metal, which were composed of X65 steel. The scanning vibrating electrode technique (SVET) and localized electrochemical impedance spectroscopy (LEIS) were used to investigate the localized corrosion behaviors of the welded joint. Scanning electron microscopy, metallographic microscopy and a micro-hardness tester were used to observe the microstructure and measure the hardness of the welded sample. Raman spectrometry and energy-dispersive spectrometry were used to measure the composition of the weldment before and after corrosion, respectively. The results show that there are the maximum micro-hardness and the densest microstructure in the welded zone compared with the other zones. In addition, alpha-Fe2O3 and Fe3O4 are present in the welded zone. The SVET and LEIS data indicate that the welded zone has the lowest current density and the largest impedance due to the presence of iron oxides and the densest microstructure, thus showing the excellent corrosion resistance. The relationship among microstructure, micro-hardness, chemical composition and local electrochemical behavior was discussed.