Premium
Studies on waterline corrosion processes and corrosion product characteristics of carbon steel in 3.5 wt% NaCl solution
Author(s) -
Li Chuanpeng,
Zhang Lunwu,
Lu Zhonghai,
Ding Rui,
Zhao Xiaodong,
Wang Bin,
Cui Hongtao,
Liu Jie
Publication year - 2021
Publication title -
materials and corrosion
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.487
H-Index - 55
eISSN - 1521-4176
pISSN - 0947-5117
DOI - 10.1002/maco.202012064
Subject(s) - waterline , corrosion , cathodic protection , diffusion , carbon steel , oxygen , metallurgy , materials science , anaerobic corrosion , electrode , chemistry , electrochemistry , composite material , physics , organic chemistry , hull , thermodynamics
The waterline corrosion behaviors of carbon steel partially immersed in a 3.5 wt% NaCl solution were investigated using the wire beam electrode technique, and the effects of corrosion products on the processes of waterline corrosion were analyzed. The results demonstrated that the initial stage and development stage of waterline corrosion were mainly controlled by the concentration and diffusion of dissolved oxygen, respectively, and the deceleration stage of waterline corrosion was mainly affected by corrosion products. The main component of the yellow corrosion products was γ‐FeOOH, and γ‐FeOOH that exhibited a high reduction reactivity could be involved in the cathodic reaction. The black corrosion products were mainly composed of Fe 3 O 4 with strong thermodynamic stability and the processes of dissolved oxygen diffusion and ion transports were obviously affected due to the continuous accumulation of Fe 3 O 4 on the surface of the electrodes. Polarity reversals were observed on the single electrodes below the waterline, but the reasons for the phenomena were different from each other.