Nondestructive Evaluation of the Creep Damaged Ni-Based Superalloy Using Ultrasonic Wave Method
نویسندگان
چکیده
The effects of microstructures during creep on the ultrasonic attenuation have been investigated for Ni based superalloy (IN738LC). The cuboidal γ′ precipitates in the virgin material became coarsened preferentially in the direction perpendicular to the applied stress axis as creep time increased. The length of γ′ precipitates increased with creep time, while the width increased slightly. The increase in the ultrasonic attenuation with increasing creep time was discussed with the increase in the equivalent size of γ′ precipitates, which was related to the scattering of ultrasonic. Ultrasonic attenuation was found to have a linear correlation with the equivalent size of γ′ precipitates. It is suggested that the ultrasonic attenuation can be used as a potential nondestructive parameter for assessing the degree of creep damage of IN738LC superalloy.
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