Title :
Life assessment of creep degraded super alloy materials using ultrasound
Author :
Saniie, J. ; Panda, B. ; Wang, T. ; Nagle, D.T.
Author_Institution :
Illinois Inst. of Technol., Chicago, IL, USA
Abstract :
The potential of ultrasound for characterizing creep damage in superalloy materials was evaluated. Several samples of IN-738, a superalloy used in many gas turbines, were heat treated at a temperature of 1520°F under 40-kpsi stress for times ranging from 500 to 900 h. Both ultrasonic attenuation and velocity measurements using a 20-MHz transducer were employed for characterizing the samples. It is shown that velocity measurements lack quantitative value since significant variability exists in the samples prior to creep damage. However, attenuation measurements clearly distinguish between fresh specimens and samples with creep damage
Keywords :
chromium alloys; cobalt alloys; creep fracture; nickel alloys; superalloys; ultrasonic materials testing; 1520 degF; Ni-Cr-Co; creep damage; creep degraded super alloy materials; fresh specimens; gas turbines; life assessment; transducer; ultrasonic attenuation; ultrasonic velocity measurements; Aging; Attenuation; Blades; Creep; Degradation; Mechanical factors; Microstructure; Turbines; Ultrasonic imaging; Velocity measurement;
Conference_Titel :
Ultrasonics Symposium, 1990. Proceedings., IEEE 1990
Conference_Location :
Honolulu, HI
DOI :
10.1109/ULTSYM.1990.171510
