High-speed heavy rails will undergo online, branch-by-branch, and full-length ultrasonic testing before leaving the factory to ensure the safety of railway transportation. Ultrasonic flaw Detectors are generally used for detection. When ultrasonic flaw Detectors are inspected, ultrasonic waves are transmitted to the inside of the heavy rail through emission and coupling, and reflected echoes are generated when encountering defect interfaces and the bottom surface of the heavy rail. The article "The Application of NDT Ultrasonic Flaw Detector in High-speed Heavy Rail Inspection" mainly introduces the application research of using UMS280 ultrasonic flaw Detector to detect heavy rail flaws. Firstly, the working principle of the ultrasonic flaw Detector is introduced; then the preparations before the on-line flaw detection are described, including the making of the sample rail, the adjustment of the flaw detection sensitivity, and the repeated calibration test of the standard sample; finally, the statistics, comparison and analysis of the on-line flaw detection of the high-speed heavy rail.
In the end, 1) NDT ultrasonic flaw Detector has a repeated accuracy rate of 99% for standard samples, and the overall performance is stable and reliable, and meets the YB/T 951-2003 flaw detection standard and the detection rail specified in the "Temporary Technical Conditions for 60kg/m Rail for Passenger Dedicated Lines" The technical requirements for the defects of head, rail waist and rail bottom can be put into use on the high-speed heavy rail flaw detection operation line.
2) The average detection rate of high-speed heavy rail flaw detection is lower than that of other heavy rails.
3) During the online detection process of the NDT ultrasonic flaw Detector, no missed detection has been found, but there are some false detections.
4) Most of the defects of high-speed heavy rails are concentrated in the rail waist area, and the main reason is related to the continuous casting and rolling process of heavy rail blanks.
5) Except for D2, F1 and F2 probes that use water-injection probes for flaw detection on high-speed heavy rails, all other probes use water-film probes with higher signal-to-noise ratio and smaller blind spots.
