Improving the efficiency of immersion ultrasonic testing of the rims of solid-rolled wheels during scheduled wheel set repairs of rolling stock

Abstract

The article is devoted to the improvement of the technology of ultrasonic immersion testing of solid-rolled wheels during scheduled repairs of wheel sets of freight and passenger wagons. The article presents a comparative analysis of immersion piezoelectric transducers from various manufacturers for their ability to detect internal defects in the area of the rim of a solid-rolled wheel adjacent to the surface of the ultrasound input. The sensitivity of immersion transducers was evaluated using alternative reference reflectors in a tuning sample in the form of cylindrical reflectors with a diameter of 5 mm in cross section B–B, G–G, D–D. The paper presents flaw detection diagrams of reference reflectors in a tuning sample using P211-2.5-20 and P211-5,0-0-16. An approach is proposed to divide the wheel rim into several zones during ultrasonic testing according to the variant of the DR2.1 and DR2.2 methods and the transition of converters from a frequency of 2.5 to 5.0 MHz in order to reduce the «dead zone», in which hidden defects may potentially lie. The experiment showed that the use of converters with a frequency of 5 MHz according to the variant of the DR2.1 and DR2.2 methods when detecting a reflector in the B–B section is preferable. Therefore, the use of P211-5,0-0-16 in general will improve the quality of immersion ultrasonic inspection during the repair of wheelsets of freight and passenger wagons. However, it should be noted that poor quality of materials used in the production of piezoelectric transducers, shortcomings in their manufacture as well as the appearance of false signals in the wheel rim control area, when using a 5,0 MHz piezoelectric converters makes it advisable to switch to a lower frequency of 2,5 MHz.