Robinson, M. J.Maitland, Julia R.2023-04-132023-04-131990-04https://dspace.lib.cranfield.ac.uk/handle/1826/19477An investigation was made into the corrosion of steel immersed in seawater by electrochemical (LPR scans) and weight loss techniques. Steel samples in the form of studs or a specially designed corrosion probe were immersed in a re-circulating laboratory based flow loop inoculated with marine microorganisms. A paralled biological study into biofilm development on corroding steel was made using viable counts, scanning electron microscopy and radio-respirometric assays. The development of a biofilm on steel studs cathodically protected at -850 mV S.C.E. and -950 mV S.C.E. was studied using these three indices of biological activity. The corrosion of steel in the real marine environment and in a bacteria-free system were monitored. Results indicate that steel corrosion followed similar trends in all these investigations. Corrosion rates were initially very high, decreased, stabilised and rose slightly. Attempts to correlate results from weight losses and LPR scans were made. Biofilms on the steel surface were very similar, and not influenced by the use or level of cathodic protection nor period of exposure. Viable counts indicate higher levels of Sulphate Reducing Bacteria were present on corroding than on cathodically protected steel. The development of a biofilm could not be correlated with trends in corrosion rates.enThesis