Base Metal Resistance of Alloys to Microbiological Influenced Corrosion, 1992 Engineering Conference Proceedings

This literature survey was undertaken to summarize published information on the microbiological influenced corrosion (MIC) of alloy base metal. Base metal attack has been reported primarily on heat exchanger tubing although occasionally on pipe and plate. MIC type corrosion failures of alloy 400, nickel, nickel-moly alloy B, alloy 800, alloy 825, nickel-chromium-moly alloy 28,904L and C706OO as well as 304 and 316 have been reported. Although C70600 tubing failed in one case, it was found to be resistant and the solution to a serious MIC problem in another case. In two evaluation programs closely simulating field conditions where MIC occurred, nickel-chromium-moly alloy C, 316,625, C71500 and TiGr2 were found resistant. No MIC service failures of the 6% MO stainless steels or titanium have been reported, despite widespread use in condensers and heat exchangers and more recently in nuclear power plant service water piping. Some laboratory evaluations have reported some degree of MIC on the 6% MO alloys, but the results to date are neither consistent nor convincing. There is a pressing need for better identification of MIC type corrosion and an equally pressing need for standard evaluation methods.