The potential for discontinuities in turbine and generator rotors must be dealt with in the manufacture of these components. In recent years it has become practical to acquire and analyze large quantities of ultrasonic data obtained from testing solid rotor forgings.
This paper describes an ultrasonic system for testing solid rotors, and discusses the detection, characterization, and imaging capability developed for evaluating rotor indications.
For detection of rotor indications, the ultrasonic signal path is divided into range windows. The signals within each window are compressed and stored for detection and characterization algorithms. Detection is performed by associating echoes from one ultrasonic path with the data from neighboring paths. These associations are constructed with respect to the cylindrical coordinate system used during the process.
Characterization is performed using the indication data sets constructed during the detection process. The final results determined by these automatic data processing algorithms are presented to the user as potential indication lists which can be correlated to images constructed from the original data.