Industrial Applications: Ultrasonic Inspection of Large Forgings

The quality control through ultrasonic inspection of forgings of large dimensions for energy industry still presents major limitations due to power losses occurring during the penetration of ultrasounds in the sample under examination. Here is reviewed the application of the pulse-compression (PuC) technique to this problem as a strategy to achieve significant increase in the signal-to-noise ratio (SNR) and therefore a corresponding improvement of the inspection capability. The performance of this technique, which exploits the linear chirp as excitation signal, and custom AVG curves for defect sizing, is analyzed both theoretically and experimentally and also the results of a thorough comparison between pulse-echo (PuE) and PuC are reported.