Corrosion research is being conducted by the Bureau of Mines to determine suitable construction materials for geothermal resource recovery plants. High chromium-molybdenum iron-base alloys, nickel- and titanium-base alloys, and titanium-zirconium-molybdenum alloy exhibited good resistance to general, crevice, pitting, and weld corrosion and stress corrosion cracking in laboratory tests in deaerated brines of the Salton Sea Known Geothermal Resource Area (KGRA) type at 232 deg. C and in brine containing dissolved carbon dioxide and methane. Only titanium-base alloys were resistant to corrosion in oxygenated Salton Sea KGRA-type brine. Copper adversely affected the resistance to general corrosion of low-alloy steels in deaerated brine, whereas chromium, nickel, silicon, and titanium improved it. Carbon steel, type 4130 steel, and types 410 and 430 stainless steels exhibited poor corrosion resistance in field tests in five brine and steam process streams produced from geothermal well Magmamax 1. These alloys were highly susceptible to pitting and crevice corrosion. General corrosion rates were high for carbon and type 4130 steels.
Geothermal Scaling & Corrosion, Ed. by L. A. Casper and T. R. Pinchback, ASTM Stp 717, 1980,