Ultrasonic Testing of Railway Transport Units with Phased Array Flaw Detectors

Abstract

The article describes possibilities of phased array flaw detectors application for testing of railway transport units, such as wheel set axles, all-rolled wheels, solebars of freight cars. The task was to reproduce the standard testing procedures using phased array flaw detectors and demonstrate their advantages in visibility, efficiency, repeatability, results validity. Unfortunately, one of the main advantages of phased array flaw detectors, namely – a possibility to control the focusing depth – are lost while testing of large scale objects.
 Sector scanning technique with the phased array flaw detectors OmniScan and Isonic 2010 in the minimum configuration was used for the research. In the all cases acoustical images of the following reflectors were obtained within the range of selected angles: saw-cuts in axles, spot-drillings and saw-cuts in wheels, side drilled holes and natural defects in solebars.
 The Multi Group software (Isonic 2000) at testing of wheel set axles has enabled the testing schemes to be realized with one prism and one phased array instead of several classical piezoelectric transducers.
 Circumferential testing of all-rolled wheels from internal lateral surface under the roll surface level has allowed transverse cracks and flange embedded defects to be detected.
 Solebar testing has been more complicated because of a form and irregularity of scanning surface, necessity of its cleaning and a complex profile of back surface. Nevertheless the usage of phased array flaw detectors has made it possible to identify the back surface profile.
 Application of phased arrays substantially increases testing efficiency and improves visibility of obtained results.