Materials Evaluation for Geothermal Applications: Plant Materials

Abstract

Electrochemical measurement techniques are being used in the initial phase of this investigation to screen materials for corrosion resistance in low pH brine, to establish the effect of pH on corrosion rate, to investigate the protectiveness of scale, and to aid in characterizing the brine itself. Apparatus has been developed to permit real time measurement of corrosion rates by means of the linear polarization resistance technique, corrosion potentials, and the redox potentials and pH of flowing hypersaline brine at 100°C. A number o flow cost and more expensive materials with various heat treatments have been tested, and their general corrosion rates correlate well with the amounts of alloying Cr and Mo. Preliminary data also indicate that the silica scale formed from unmodified brine affords some protection against corrosion in acidified brine.