Evaluation of Materials Exposed to High-Velocity, High-Salinity, Highly Mineralized Geothermal Brine

摘要

Using surface traces, scanning electron microscopy, and light microscopy, Ti-, Co-, Ni-, and Fe-base alloys were evaluated for erosion and stress corrosion cracking (SCC) after exposure at about 104 exp 0 C to the nozzle exhaust from acidified geothermal brine. Examples of erosion, SCC, and corrosion are shown. Results are evaluated in terms of synergism between erosion, corrosion, and stress. Repassivation kinetics might play a key role in the formation and growth of erosion cavities. Of the materials tested, the Ti-base alloys appear to have the best combination of resistance to SCC and erosion/corrosion in high-salinity, highly mineralized, acidified, two-phase nozzle exhaust. (ERA citation 04:018605)