Possibility of detection of crack initiation in high temperature water

摘要

The initiation of stress corrosion cracks in sensitised austenitic stainless steel under high temperaturewater conditions (simulated boiling water reactor environment) was detected, applyingelectrochemical noise measurement technique. The stress corrosion cracks were generated on pre-oxidised, unnotched standard tensile round bar specimens under constant load conditions. Theelementary transients associated with stress corrosion crack initiation were found to be embedded inthe basic noise pattern coming from the oxide growth reaction on the tensile specimen. Thus a simplecalculation of standard deviations to identify localised corrosion phenomena under high temperaturewater conditions cannot be used. The changes in the track of power density spectra proved to bemuch more suitable to indicate stress corrosion crack initiation under high temperature waterconditions.