Accelerated estimation of corrosion rate in supercritical and ultra-supercritical water

Abstract

Corrosion rate: Fast measurement for metals in supercritical water Measurement of corrosion rates in ‘difficult’ environments is an ever-present challenge to corrosion engineers. An accelerated methodology to enable the corrosion rate of steel and nickel alloys in supercritical water under realistic conditions is presented. Supercritical water—a dense gaseous state at high temperature and pressure—is an attractive heat transfer medium for nuclear and coal-fired power stations, as it enables high heat transfer efficiency. Measuring corrosion rates for metals exposed to supercritical water is tricky to perform in situ however, necessitating long-term exposure tests. While accelerated tests have been reported, these did not use environments equivalent to those experienced in-service. However, David Rodriguez and Dev Chidambaram from the University of Nevada Reno in the USA now demonstrate the use of electrochemical analyses for assessing corrosion rate under realistic conditions, achieving results comparable to those from long-term gravimetric testing. This allows experiment times to be reduced from weeks or months, to less than a day.