Sensitivity Research of Ultrasonic Testing of Wheel Pair Axles of Railway Rolling Stock

Ultrasound control testing of railway rolling stock wheel axles is to detect fatigue and manufacturing defects taking into account part dimensions and distances sound waves pass in steel, and requires appropriate sensitivity assessment so as the applied testing method to be valid. That is why sensitivity to reflectors of specified sizes is useful to define reliability improvement methods of axle ultrasound testing. Such studies remain quite relevant. The article studies the effect of acoustic characteristics of an object and a reflector on pulses reflected from them during ultrasound testing of railway wagon wheel axles. Wheel axles of railway wagons of РУ-1Ш and РВ2Ш type and notches representing segments in the specifies section as reflectors were applied for the study. The study results show that at long distance from source converter and pulse receiver changes in reflector sizes slightly contributes to the reflected pulse generation. This is characteristic both for distances from 160 to 1,900 mm and for the cases when both direct and angle converters are applied for the testing. Taking into account considerable sensitivity variations, it is expected the sensitivity testing level to be adjusted in accordance with noise level to increase the reliability of ultrasound testing of railway rolling stock wheel axles. The application of the discussed method allows for appropriate assessment of sensitivity testing for each axle at different portions and fix it for further comparative testing of every part to be used.