STEEL CORROSION MECHANISMS; THE GROWTH AND BREAKDOWN OF PROTECTIVE FILMS IN HIGHTEMPERATURE AQUEOUS SYSTEMS, STUDIES WITH 15% NAOH AT 316C.
Abstract
The report summarizes what is known regarding the reaction of steel with high-temperature water as affected by sodium hydroxide additions and also presents results of a detailed study, using the hydrogen effusion method, of the reaction of steel with 15-percent sodium hydroxide solution at 316C. The corrosion rates are correlated with a microscopic study of the growth and breakdown of the protective magnetite (Fe3O4) film. There are two different corrosion-rate-governing mechanisms involved prior to the onset of pitting: a large decrease of the initial corrosion controlled by the build up of a protective film on the metal surface, and a subsequent smaller decrease in corrosion rate possibly controlled by penetration of the magnetite film by the corrosive solution. The pitting is apparently due to the genesis of cracks in the magnetite film after it reaches a critical thickness. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Apr 17, 1964
- Accession Number
- AD0608334
Entities
People
- G. N. Newport
- M. C. Bloom
- W. A. Fraser
Organizations
- United States Naval Research Laboratory