1992 Volume 41 Issue 471 Pages 1729-1735
In order to attempt the nondestructive detection of creep damage by ultrasonic technique, the changing behavior of the energy attenuation coefficient of ultrasonic shear wave with creep damage was investigated by using SUS316 steel. Two kinds of energy attenuation coefficients, αst and αsL, were measured, in which the ultrasonic shear stress acted in the parallel and normal directions to the loading axis, respectively. The energy attenuation coefficients changed in a reasonable manner in which some intrinsic types of creep damages, such as the deformation of grains, the change of dislocation structure, the progress of aging, and the nucleation of microcracks, were reflected. Moreover, the relative ratio of αst/αsL monotonically increased with creep damage. From the above results, it was concluded that the absolute and relative properties of ultrasonic attenuation may be useful for the nondestructive creep damage detection of materials with high creep rupture ductility, as a potential measure.
