Effect of hydrogen on pitting corrosion of 2205 duplex stainless steel under alternating dry/wet marine environment

• Published in: International journal of hydrogen energy Vol. 48; no. 47; pp. 17983 - 17994
• Main Authors: Li, Gengxin, Du, Min, Wang, Jing, Huang, Guosheng, Ma, Li
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.06.2023
• Subjects: 2205 duplex stainless steel; Alternating dry/wet; Hydrogen; Pitting corrosion; Alternating dry/wet; Pitting corrosion; 2205 duplex stainless steel; Hydrogen
• ISSN: 0360-3199; 1879-3487
• DOI: 10.1016/j.ijhydene.2023.01.210

Stainless steels play an extremely vital role in the field of marine engineering equipment. However, stainless steel products in service are still subject to corrosion from severe environments such as alternating dry/wet condition and damage caused by hydrogen introduced during heat treatment or cathodic protection. Under alternating dry/wet marine environment, the synergistic effect of hydrogen and corrosion can influence the corrosion resistance of stainless steels dramatically. In this work, the corrosion behavior and mechanism of 2205 duplex stainless steel under alternating dry/wet marine environment are investigated before and after hydrogen charging using electrochemical testing, component characterization and morphological observation. The results show that the open circuit potential, film resistance and breakdown potential all reduce and the passive current density increases after 12 h hydrogen charging. The ratio of Fe3+ and O2−/OH− decreases. The components of the hydrogen charged passive film alter and the performance deteriorates. The number of surface pits increases after 12 h hydrogen charging and additional 10 d alternating dry/wet corrosion. The pitting potential drops much lower. Consequently, The synergistic effect of high concentrations of Cl− in the thin liquid film and hydrogen accelerates the destruction of the passive film, further reducing the corrosion resistance of stainless steels. •The corrosion behavior of hydrogen-charged duplex stainless steel under alternating dry/wet environment was investigated.•Alternating dry/wet environment and hydrogen have a synergistic effect on the breakdown of passive films.•Hydrogen-charged stainless steel accelerates pitting growth after alternating dry/wet corrosion.•3D model is adopted to analyze the mechanism of corrosion stages of duplex stainless steel.