LONG-TERM MEASUREMENTS OF THE CORROSION OF MILD STEEL IN 580F NaOH SOLUTIONS
Abstract
Extended measurements have been made, using the hydrogen effusion technique, of the corrosion of low-carbon steel in static waters containing up to 40% NaOH at 580F. Minimum corrosion was found at 1 to 2% NaOH, the corrosion mode being distinctly different on either side of the minimum. The low- concentration corrosion rates fell smoothly and rapidly from 1000 to 10,000 mg Fe/sq dm mo to less than 100 mg Fe/sq dm mo, whereas, with 10 to 40% NaOH, the rate curves followed a 'peak/plateau/sudden-drop' course wherein the rates ranged from 300,000 mg Fe/sq dm mo at the highest peak to about 100 mg Fe/sq dm mo after the final drop. These behaviors were explained as resulting from a passive to active corrosion state transition which occurs at the corrosion minimum, i.e., at 1 to 2% NaOH, with the high-concentration active-state specimens subsequently passivating spontaneously after some certain degree of corrosion has transpired. It was shown that there is some reason to believe that these two mechanisms may be involved in the pitting and stress corrosion cracking of mild steel exposed to high-temperature, high-alkalinity environments.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jul 13, 1970
- Accession Number
- AD0710370
Entities
People
- Robert L. Jones
Organizations
- United States Naval Research Laboratory