| 摘要 |
PURPOSE:To measure the wall thickness of a steel pipe along the entire surface in the circumferential direction on line and to omit cutting and inspection off line by setting short and small inspection blocks in the longitudinal direction of the steel pipe, collecting the data of the wall-thickness values for every inspection block with a rotary electromagnetic ultrasonic-wave wall-thickness gage, and judging pass or fail. CONSTITUTION:At first, the data of the tips and crop parts 101 and 102 of a steel pipe are not obtained. At the intermediate part of the pipe, short, small inspection blocks 103 which are divided into small sections at a specified interval are set. A rotary head 1 of a wall thickness gage 10 is rotated at a high speed during the measurement of the wall thickness. First and second measuring heads 5 and 6 which are provided in the head 1 each have four probes 11 which are arranged in the longitudinal direction of a pipe to be inspected 100 at a specified interval. Each probe picks up the wall thickness data of about 96 points per rotation. The measured data are collected at the length of every inspection block. Thus, the wall-thickness value data are collected for every inspection block 103 by the spiral scanning of each probe 11. The pass or fail of the inspection block is judged for the group of the collected measured data. |
