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Inflection of backward sweep of cyclic polarization curve: Pit transition potential E ptp
Author(s) -
Sun Qingqing,
Chen Kanghua
Publication year - 2018
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.201810419
Subject(s) - inflection point , polarization (electrochemistry) , metastability , materials science , chloride , ion , chemistry , metallurgy , mathematics , geometry , organic chemistry
The influences of ex‐situ applied load, scan circle, reverse potential, chloride concentration, and temperature on inflection ( E ptp ) of backward sweep of cyclic polarization of 7150 Al alloy were investigated. The 2nd derivative of polarization curves was used to accurately determine the value of E ptp . E ptp is determined as the potential where massive metastable pits finished their repassivation process during reverse scan, providing an insight into highly constricted forms of localized corrosion repassivation. Chloride ion and diffusion condition have predominant effects on this inflection. E ptp showed non‐monotonic trend with temperature and relevant discussion was given as well.