Ultrasonic NDT of the Material of Working Blades of High Pressure Turbo Compressor

摘要

Shear waves possess large information in the study of the technical condition of engineering materials. In the case of occurrence of stress or plastic deformation along a certain direction, the velocity of shear waves polarized along and across of this direction will vary in different ways. A value characterizing this difference is parameter of acoustic anisotropy - the relative difference of velocities of mutually perpendicularly polarized shear waves. The report shows the results of measurement of that parameter in the basic metal of blades made of heat resistant stainless steel, in the post-exploitation condition and after subsequent heat treatment. Thermal processing has been done to normalize the structure of the material before applying the strengthening coating. Observed data were confirmed by the results of metallographic analysis using raster optical microscope.