Abstract

CALDERON-HERNANDEZ, José Wilmar; BRAGA LUZ, Iara Beatriz; HINCAPIE-LADINO, Duberney  and  ALONSO-FALLEIROS, Neusa. Study of pitting corrosion resistance of austenitic stainless steels: influence of the manganese addition in solid solution. Rev. ion [online]. 2015, vol.28, n.1, pp.63-72. ISSN 0120-100X.

In this research are shown the results about the study of the influence of manganese in solid solution on the pitting corrosión resistance of austenitic stainless steels, a steel is referred to as 17Cr6Mn5Ni and the UNS S304L steel as benchmarking material. Electrolytic solution containing 0.6M NaCl in three different oxygen concentration were used (aerated, non aerated and naturally aerated). The behavior of each condition was measured through potentiodynamic polarization tests and metallographic examinations. The values of corrosion potential (Ecorr) and pitting potential (Ep) were determined. The oxygen concentration of the electrolytic solution influenced the Ecorr but not the Ep parameter. Manganese in solid solution benefits the Cl- ions absorption in austenitic stainless steels. Therefore, causes negative effect on pitting corrosion resistance. A mechanism was proposed through the standard Gibbs free energy of formation of compounds (ΔG°) data, and through the competitive absorption theory.

Keywords : pitting corrosion; manganese; oxygen; austenitic stainless steels.

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