Solid axle defect detection technique based on phased array ultrasonics

The quality of train axles is especially important for the safety of railway transportation. A technique and system based on the newest Olympus phased array ultrasonic instrument, the FOCUS PX, for the detection of defects in on-train solid axles is presented in this paper. Advanced phased array ultrasonic technology, the ultrasonic transmitting and receiving principle, and the ultrasonic testing method for solid axle defect detection are explained in detail. With this technique, transverse defects in axles can be detected by coupling from the end face of solid axles. There is no need to dismount wheel-sets from the train or remove coating for ultrasonic inspection. A real inspection system based on this technique, named the LZM In-Service Automatic Ultrasonic Inspection System for Solid Axles (hereinafter referred to as “LZM system”), which has a high level of efficiency and reliability, is described in detail. Half of the axle can be covered by ultrasonic beams from each side, and ultrasonic data can be acquired in 20 seconds. The inspection results are displayed in A-scans and B-scans for correlative data analysis, and all inspection data are recorded.