Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
860473 | Procedia Engineering | 2013 | 6 Pages |
Austenitic 316L(N) stainless steel specimens subjected to total strain controlled fatigue and creep-fatigue cycling at 923 K have been investigated to correlate the observed microstructural features with ultrasonic measurements. Samples were subjected to ultrasonic velocity and attenuation measurements at room temperature and at elevated temperatures (300 K to 623K). Both longitudinal and shear wave transducers were employed for the ultrasonic measurements at the optimum frequency of 5 MHz. The large reduction in the magnitude of the velocity in 10 min hold creep-fatigue sample is attributed to the combined or individual effect of increased amount of inelastic deformation, creep damage and oxidation. Observed higher magnitude of decrease in velocity and increase in attenuation beyond the measurement temperature of 450 K reveals the potential of ultrasonic measurements for on-line monitoring of fatigue and creep-fatigue damage that occur during service. The study is also useful in estimating the elastic properties of the creep-fatigue damaged materials at elevated temperatures through ultrasonic measurements.