Evaluation of Polarization Curves for Copper Alloys Exposed to Natural and Artificial Seawater
Abstract
Polarization curves have been recorded in the vicinity of the corrosion potential Ecorr as a function of rotation rate for rotating cylinder electrodes of 99Cu, 90CU:10Ni, 70CU:30Ni, admiralty brass and aluminum bronze which had been exposed to natural and artificial seawater for time periods up to 1 0 weeks. The polarization curves were analyzed with the POLFIT software to determine the Tafel slopes b a and b c and the corrosion current density E corr. While E corr showed a linear dependence on r0.7 in most cases, Ecorr was independent of mass transport. This result was explained by mass transport control of both the anodic and the cathodic reaction determining the corrosion rate. Corrosion rates have also been obtained for a 30 day period using a commercial corrosion rate monitor and by weight loss for periods up to three months. While corrosion rates obtained with these two methods agreed for exposure in artificial seawater, corrosion rates determined with the linear polarization technique underestimated corrosion rates based on weight loss data in natural seawater by a factor of two or more. Biofouling, Corrosion, Biodeterioration, Electrochemistry.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 01, 1992
- Accession Number
- ADA252835
Entities
People
- Bryan Little
- Cheng-Ying Tsai
- F. Mansfeld
- G. Liu
- H. Shih
Organizations
- United States Naval Research Laboratory