The Inhibition of Vapor-Phase Corrosion. A Review
Abstract
This report documents a limited literature review on vapor phase corrosion and its inhibition. The direct cost of atmospheric corrosion of metals and alloys in the United States alone has been estimated to be between $5 billion to over $20 billion annually. This atmospheric corrosion, known by some researchers as vapor phase corrosion (VPC), is due to the individual and combined action of oxygen, moisture, and atmospheric pollutants. Additional contributors to VPC are rain, snow, dust, soot, ash, wind, and radiation (light, heat, etc.). The rate of VPC may be accelerated by both acids and bases, depending upon the metal. Rosenfeld showed that the mechanism of this attack is electrochemical, in which the electrolyte is composed of a thin film of humidity on the surface of the metal. Detrimental effects caused by photochemical reactions of sulfur dioxide and nitrogen oxides have been demonstrated. Classical methods of protecting equipment from atmospheric attack include (a) using coating materials or paints and (b) alloying the metal to increase its resistance to corrosion. An effective and relatively inexpensive method of controlling VPC in closed environments is through the use of vapor phase corrosion inhibitors (VCI). These materials, while having an appropriate vapor pressure, possess high passivating properties, strong tendencies toward surface adorption, and the ability to form a comparatively strong and stable bond with the metal surface.
Document Details
- Document Type
- Technical Report
- Publication Date
- Oct 01, 1985
- Accession Number
- ADA163430
Entities
People
- George E. Fodor
Organizations
- Southwest Research Institute