Study of Corrosion Behavior of a 2507 Super Duplex Stainless Steel: Influence of Quenched-in and Isothermal Nitrides
2014 (English)In: International Journal of Electrochemical Science, ISSN 1452-3981, Vol. 9, no 1, 61-80 p.Article in journal (Refereed) Published
Precipitation of different types of chromium nitrides may occur during processing of super duplex stainless steels, affecting the properties of the material. In this study the influence of quenched-in (size range ca. 50-100 nm) and isothermal (size range ca. 80-250 nm) types of nitrides on the corrosion behavior of a 2507 super duplex stainless steel has been investigated at room temperature and at 90 degrees C (above the critical pitting temperature) in 1 M NaCl solution. The microstructure has been characterized by scanning electron microscopy and magnetic force microscopy. The isothermal nitrides exhibit a higher Volta potential compared to the matrix, but such difference could not be observed for the quenched-in nitrides. In-situ electrochemical AFM measurements at room temperature show stable surfaces for a wide range of applied potentials despite the presence of either type of nitrides. In the transpassive region isothermal nitrides appear to be slightly more deleterious than quenched-in nitrides. At 90 degrees C isothermal nitrides largely reduce the corrosion resistance of the austenite phase, while the quenched-in nitrides reduce the corrosion resistance of the material to a much lesser extent. The size difference between isothermal and quenched-in chromium nitrides may be crucial, in particular above the critical pitting temperature.
Place, publisher, year, edition, pages
2014. Vol. 9, no 1, 61-80 p.
Duplex stainless steel, nitrides, exposure tempera ture, atomic force microscopy, corrosion
IdentifiersURN: urn:nbn:se:kth:diva-129354ISI: 000328931100006ScopusID: 2-s2.0-84891050891OAI: oai:DiVA.org:kth-129354DiVA: diva2:651801
QC 20140123. Updated from accepted to published.2013-09-272013-09-272014-01-23Bibliographically approved