O2 Electroreduction on Ni-Cr-Mo Alloys

Rogers, S.P. ; Gervasio, D.F. ; Payer, J.H.

United States. Department of Energy. Yucca Mountain Project Office.

关键词: Corrosion;    Oxidation;    Oxygen;    36 Materials Science;    Potassium Nitrates;   

DOI  :  10.2172/893899
RP-ID  :  NA
RP-ID  :  NA
RP-ID  :  893899

美国|英语

来源: UNT Digital Library

【 摘 要 】

Oxygen (O{sub 2}) reduction is the most likely process for sustaining metal oxidation in air through electrochemical ''local cells'' on the metal surface. O{sub 2} reduction occurring at one surface site is the sink for electrons generated during metal oxidation at another. Metal corrosion is reduced when O{sub 2} reduction is slowed or arrested; a process that leads to ''cathodic stifling'', O{sub 2} reduction sites become alkaline through the generation of hydroxide. The O{sub 2} reduction of two Ni-Cr-Mo alloys, i.e. C22 and C276 alloys, was studied in a half-cell with aqueous KOH electrolyte to learn the behavior of the O{sub 2} reduction local cells on the passive metal surface. This is to give experimental inputs to computational methods for predicting alloy corrosion. Fresh and aged alloy metal surfaces were studied in alkaline aqueous media with and without nitrate (1M KNO{sub 3}) in the presence and absence of O{sub 2}-Alloy behavior was characterized by electrochemical impedance spectroscopy (EIS) and voltammetry with a still electrode and a rotating ring-disk electrode (RRDE). A spectroscopic graphite rod was the auxiliary electrode, and Saturated Calomel (SCE) was the reference electrode.