Download or read book Localized Corrosion in Materials for Geothermal Power. Final Report written by and published by . This book was released on 1982 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The influence of 16 different geothermally related environments on a number of potentially useful steels was examined for both general and localized corrosion and at ambient and 150°C. Variation in chloride concentration of 1 to 20% generally demonstrated only minor aggressiveness in acidified solutions. In general, the presence of H2S raised the corrosion rate. However, very low concentrations (10 ppM) indicated higher rates than in saturated brines. This is rationalized on the basis of the inability to develop a semi-protective film at the low H2S concentration. The corrosion rate for the Cr-Mo steel was unexpectedly high at ambient, but improved substantially at 150°C. The Ni-Cu-Nb steel consistently demonstrated excellent resistance in all environments, except the 10 ppM H2S at ambient. At 150°C there were no exceptions to its superior performance. Maximum pit depth studies, analyzed statistically, indicated that the Ni-Cu-Nb alloy was the most resistant to localized attack. A clean (low inclusions) Mn-C and a clean vacuum melted steel ranked well. A comparison of two almost identical Mn-C steels one clean and one dirty clearly indicated the deleterious influence of inclusions on the tendency for localized corrosion. The profiling of a protected section of a creviced or pitted sample helped to delineate the nebulous line of demarcation between general and localized corrosion in these low alloy steels.