A calibration method based on the reconstruction for automatic ultrasonic flaw detection of the upset region of the drill pipe

Abstract

The problem of inability to calibrate due to uneven thickness in automatic ultrasonic testing used for the upset region of the drill pipe was studied. A water-immersion ultrasonic testing system was established to accomplish the inspection for this area and provide the defects information for post process. A real-time tracking method based on surface reconstruction was present to ensure all of the artificial defects to be accurately detected. An adjusting algorithm for the data was performed to update the detecting results, so that the fitted curve was favorable for calibration. A sample pipe with through-holes was test with the system. The experimental results showed that all of the artificial defects could be detected after surface reconstruction and the adjusted data could provide the basis for the quantification of flaw, all of which had proved the data adjusting algorithm to be effective.