Pitting corrosion of martensitic stainless steel in halide bearing solutions

• Published in: Corrosion science Vol. 112; pp. 233 - 240
• Main Authors: Pahlavan, S., Moazen, S., Taji, I., Saffar, K., Hamrah, M., Moayed, M.H., Mollazadeh Beidokhti, S.
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.11.2016
• Subjects: A. Stainless steel; B. Polarisation; B. Potentiostatic; C. Pitting corrosion; B. Potentiostatic; B. Polarisation; C. Pitting corrosion; A. Stainless steel
• ISSN: 0010-938X; 1879-0496
• DOI: 10.1016/j.corsci.2016.07.008

•Effect of halide anions on the pitting of stainless steel was investigated.•The smaller the ionic radius, the more activity in the pitting initiation.•F− alongside with the Cl− has a two-sided effect on the pitting corrosion.•F− alongside with the Cl− raises the occurrence frequency of metastable pits.•F− alongside with the Cl− raises the pitting potential. In this research, pitting corrosion of martensitic stainless steel in presence of halide anions was investigated by using polarization techniques. Results confirm that the aggressivity of halides increases in the following order: I−<Br−<Cl−. Although fluoride does not offer any pitting by itself, its presence together with chloride increases the occurrence frequency of metastable pits and pitting potential, simultaneously. While the pitting was more probable in NaCl solution, its metastable stability product was observed equal or even less than other solutions.