Reliability research on automatic ultrasonic testing (AUT) technology of land long distance pipeline with automatic welding joint

The complete automatic ultrasonic testing (AUT) reliability theory and evaluation system were established for automatic welding joint of long distance pipeline. The reliability of AUT system was verified by several indexes, including Probability of Detection (POD), Probability of Sizing (POS), Probability of False Alarm (PFA), Probability of Rejection (POR) and Receiver Operating Characteristic (ROC). In order to evaluate AUT process and analysis reliability of AUT system, the sample size was optimized to 46 and the quantitative data of defects in AUT, RT and macroscopic metallographic section were analyzed statistically, which could directly provide reliable quantitative bases for the automatic welding quality acceptance of AUT Technology. The results show that POD and reliability of AUT are not less than RT, which can provide support for AUT application to automatic welding of the domestic long distance pipeline.