Ultrasonic evaluation of creep damage in steel

Abstract

Creep processes are the main processes responsible for the failure of structural materials in prolonged service at high temperatures and pressures. Failure starts with the formation of cavities in the material. This paper deals with an ultrasonic method to evaluate creep damage. Measurements of both ultrasonic attenuation and velocity, together with improved theoretical models, allow the porosity of the material and the size and concentration of cavities to be determined. Good agreement between the results and data obtained from a metallographic study indicates the usefulness of the method for in-service evaluation of creep damage.