Thermographic investigation of the fatigue behavior of reactor pressure vessel steels

The fatigue behavior of reactor pressure vessel (RPV) steels during fatigue testing was monitored by an advanced, high-speed, high-sensitivity, nondes tructive evaluation (NDE) technique called infrared (IR) thermography. Five stages of temperature profiles during fatigue were recorded: an initial in crease of the mean specimen temperature followed by a temperature decrease, a constant (equilibrium) temperature region, an abrupt temperature increas e, and a temperature drop after the specimen failure. Using the state-of-th e-art IR camera, the temperature profiles were recorded cycle by cycle duri ng 20 Hz fatigue testing. A theoretical model combining the thermoelastic, inelastic, and heat-conduction effects were used to explain and predict the temperature evolution during fatigue. Specifically, the temperature evolut ion was predicted, and the results were found to be in good agreement with the experimental data. (C) 2001 Elsevier Science B.V, All rights reserved.