Since geothermal wells are a feasible energy source to replace fossil fuel supply, many technologies have been developed to take advantage of geothermal energy. Nevertheless, service conditions in geothermal facilities are due to the chemical composition of hydrothermal fluids and temperatures, in many cases, extreme in terms of corrosion. Therefore, materials selection based on preliminary material qualification is essential to guarantee a secure and reliable operation of the facilities.
This contribution deals with the evaluation of the corrosion behavior of duplex steel S31803 (318LN, X2CrNiMoN22-5-3, 1.4462) conducted by electrochemical measurements and exposure tests in artificial geothermal waters simulating the conditions in different locations with geothermal potential in Germany.
The duplex steel S31803 shows limited suitability for applications in artificial geothermal waters due to its susceptibility to pitting and crevice corrosion.
For low saline geothermal waters it can be considered suitable at moderate temperatures. Slight crevice corrosion susceptibility needs to be considered.
Results are being incorporated into a materials catalogue for geothermal applications which shall provide basic information for designers and users of geothermal facilities.
Keywords: downloadable, S31803, crevice corrosion, duplex steel, geothermal energy