Nondestructive Characterization of Pitting Corrosion Damage and Fatigue Life 983127

Microradiographical and ultrasonic methods for the determination of pitting corrosion depth is discussed. Fatigue crack initiation and growth from artificial pits of different depths is studied experimentally. The experime-ntal results were analyzed using fracture mechanics models including those for small cracks. The model shows very good agreement with experiment in describ-ing the initiation and growth of a crack emanating from a pit and in predicting the dependence of the reduction of fatigue life on pit size. Using this analysis, a relation between the depth of the corrosion pit and the fatigue life is established, and thus the prediction of fatigue life of the sample with corrosion pit is related to the radio-graphic and ultrasonic measurements.