J. Mater. Sci. Technol. ›› 2026, Vol. 260: 113-123.DOI: 10.1016/j.jmst.2025.09.056

• Research Article • Previous Articles     Next Articles

Passive film response of Ti-6Al-4V alloy welded joints to hydrostatic pressure in simulated deep-sea environments

Cui Yua,b,*, Jin Guoa, Du Shuangyub,c, Liu Junb,c, Liu Ruic, Wang Fuhuic, Liu Lic,*   

  1. aInstitute of Surface/Interface Science and Technology, Key Laboratory of Superlight Material and Surface Technology of Ministry of Education, College of Material Science and Chemical Engineering, Harbin Engineering University, Harbin 150001, China;
    bShenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, China;
    cState Key Laboratory of Digital Steel, Northeastern University, Shenyang 110819, China
  • Received:2025-07-24 Revised:2025-09-19 Accepted:2025-09-22 Published:2026-07-20 Online:2026-10-13
  • Contact: *E-mail addresses: ycui@imr.ac.cn (Y. Cui), Liuli@mail.neu.edu.cn (L. Liu)

Abstract: The passive films formed on distinct regions (heat-affected zone (HAZ), base metal (BM), and weld metal (WM)) of Ti-6Al-4V alloy welded joints were comparatively investigated under hydrostatic pressures of 0.1 and 15 MPa in a simulated deep-sea environment. Results demonstrate that elevated hydrostatic pressure significantly degrades the corrosion resistance of passive films, with region-dependent susceptibility following the order: HAZ > BM > WM. This phenomenon is attributed to the synergistic interaction between hydrostatic pressure and residual stress. Among them, the residual tensile stress in HAZ enhances the effect of hydrostatic pressure, which greatly increases the density of defects in the passive film. Conversely, the compressive residual stress in WM exerts a protective effect, mitigating the detrimental influence of hydrostatic pressure on passive film integrity. The reduction of V content in β phase in the WM region improves the stability of the passive film.

Key words: Hydrostatic pressure, Titanium alloy, Welded joint, Passive film