An Evaluation of Titanium Exposed to Thermophilic and Marine Biofilms
Abstract
Flat coupons of Grade 2 titanium were immune to microbiologically influenced corrosion in high temperature environments (5570 deg C) containing sulfur-oxidizing (SOB and sulfate-reducing bacteria (SRB). SM0254 was heavily pitted after similar exposure to thermophilic SRB. Hydrides did not form in titanium weld regions exposed to thermophilic hydrogen-producing bacteria. After a one year exposure to Pacific Ocean seawater, grade 2 titanium and SMO 254 were colonized by diatoms and other algal species. E corr increased continuously for the stainless steel, but not for titanium. The latter result can be explained by the poor catalytic activity of the oxide layer on titanium for oxygen reduction. The capacitance obtained with electrochemical impedance spectroscopy (EIS) remained constant for both metals with titanium showing values close to the theoretical value normally observed only for inert materials. The high values of the polarization resistance (R sub p) and the capacitive nature of the impedance demonstrate that the materials remained in the passive state throughout the entire period. Titanium, Microbiologically influenced corrosion, Extreme environment.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 01, 1993
- Accession Number
- ADA269620
Entities
People
- Brenda J. Little
- Patricia A. Wagner
- Richard I. Ray
Organizations
- United States Naval Research Laboratory