Predicting Galvanic Corrosion of Structural, Passive, Metal Alloys in Evolving Atmospheric Environments
Abstract
This work summarizes the results of a 5-year project to investigate and develop an improved theoretical understanding of the physical, chemical, and electrochemical processes and reactions occurring in atmospheric corrosion. A numerical model of a galvanic couple between an aircraft structural aluminum alloy and a precipitation-hardened stainless steel was developed and the outcomes compared to an experimental system to determine how changes in solution resistivity, dissolved oxygen concentration, and chemical reactions in the electrolyte change the corrosion current in the galvanic couple within a thin film electrolyte. Discrepancies between the model and experiments are analyzed and a mechanism that relies on chemical reactions in the electrolyte to form corrosion products that block ion transport and suppress further oxidation is proposed. Through the cumulative work presented here, an improved understanding of the effect of electrolyte and corrosion products on the ability to sustain galvanic current is obtained. These results will be incorporated into future atmospheric galvanic prediction models used by the Navy.
Document Details
- Document Type
- Technical Report
- Publication Date
- Sep 25, 2023
- Accession Number
- AD1211601
Entities
People
- Carlos M Hangarter
- Rachel M. Anderson
- Steven A. Policastro
Organizations
- United States Naval Research Laboratory