Naslov
Passivity of Nitrogen-Bearing Stainless Steel in Acidic Solution

Autori
Martinez, Sanja ; Metikoš-Huković, Mirjana ; Lajci, Nushe

Vrsta, podvrsta i kategorija rada
Poglavlja u knjigama, ostalo

Knjiga
Passivation of Metals and Semiconductors, and Properties of Thin Oxide Layers : A Selection of Papers from the 9th International Symposium

Urednik/ci
Marcus, Phillipe ; Maurice, Vincent

Izdavač
Elsevier

Grad
Pariz

Godina
2006

Raspon stranica
35-40

ISBN
978-0-444-52224-5

Ključne riječi
stainless steel ; nitrogen bearing ; point defect model

Sažetak
The mechanism and kinetics of the passivation process, the mechanisms of charge transfer and potential distribution in the system NTR50 steel/passive film/0.5 M H2SO4, were studied using transient electrochemical techniques in combination with cyclic voltammetry and the earlier results of XPS analysis. It has been established that the point defect model that takes into account the interfacial kinetic effects presents the best fit to the experimental data yielding physically reasonable parameters. It has been applied to quasi-stationary experimental data to determine: (i) the transfer coefficient for the metal dissolution reaction through the barrier film, alpha 11 = 0.017 (ii) the coefficient of proportionality between the barrier film/solution potential and the applied potential, alpha = 0.446 and (iii) the electric field, epsilon = 4.4 x 106 V cm-1. Cation vacancies, V represents the main charge carriers under quasi – stationary conditions of formation and growth of the barrier Cr2O3 film. The barrier layer on NTR50 stainless steel is essentially a cation conductor. The outward migrating species are presumed to be the Fe3+ ions and the molybdenum ions, Mo4+ and Mo6+, which is consistent with film composition comprised of an inner Cr2O3 barrier layer and a Fe-rich outer hydrated layer.

Izvorni jezik
Engleski

Znanstvena područja
Kemija, Kemijsko inženjerstvo

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