Ultrasonic crack detection (defect size evaluation)

Abstract

The necessity of analysing and assessing the quality and strength of components without incurring damage on the specimen under test has given rise to a variety of 'Non-Destructive Tests'. Non-destructive testing embraces mainly such techniques as: Radiographic inspection (using either Gamma or X-Rays), magnetic particle inspection, electrical inspection (using a.c. eddy current methods or d.c. search coil), dye penetrant inspection and last but not least Ultrasonic Flaw Detection. The use of ultrasonic beams as a non-destructive method of testing for flaws in engineering components is being applied to the examination of welds, plates, tube and even railway lines. Besides this ultrasonics are being used also for the inspection of forged parts and to a lesser extent on non-metallic components. The main problem of using ultrasonics lies in the right interpretation of results obtained when flaws are detected. The object of this work is thus to forward a study of the mode of application of ultrasonics (using the Krautkramer Flaw Detector) presenting the limitations and difficulties involved and submitting results with the ultimate aim of aiding the operator to give a more accurate and correct interpretation of results obtained by the use of the above equipment.