20th International Forgemasters Meeting - IFM 2017

Forgings, being usually one of the most critical components (like in power generation machinery), require intensive volumetric inspection to guarantee a sufficient lifetime. This is usually accomplished by manual or automated ultrasonic testing. We are reporting about a game changer in ultrasonic testing: Ultrasonic Computed Tomography uses analytics to reconstruct the volume (a linearized diffraction tomographic approach for the solution of the inverse problem). This improves the SNR allowing an increase of sensitivity by up to an order of magnitude and to displays indications spatially and visually correct in the 3D volume. The method is an imaging algorithm, based on the Synthetic Aperture Focussing Technique (SAFT). The applied software is a brand new implementation of SAFT with a strong focus for a large scale industrial application: the complete 2D as well as 3D imaging of ultrasonic inspections of heavy rotor forgings. This paper shows the working principle of the method along with the first results and computation times. Ultrasonic Computed Tomography was also awarded by the Werner von Siemens Award as one of the Top 15 ingenuity programs.