Three-dimensional positioning method for ultrasonic detection of internal defects of thick-walled pipes

Abstract

The invention belongs to the technical field of detection of thick-walled pipes, in particular to a three-dimensional positioning method for ultrasonic detection of internal defects of thick-walled pipes, including step S1, using an ultrasonic flaw detector to perform ultrasonic detection of internal defects by using a pulse reflection method; S2, placing the probe in the The circumferential surface of the thick-walled pipe is scanned clockwise and counterclockwise. The three-dimensional positioning method for ultrasonic detection of internal defects of thick-walled pipes, by setting S1, using an ultrasonic flaw detector, and adopting the pulse reflection method to conduct ultrasonic detection of internal defects; S3. At this time, the position of the probe in the longitudinal direction of the thick-walled pipe is the length of the defect. The length of the defect can be measured by using the 6dB method, which can detect the inside of the ultra-thick-walled pipe with the thickness-to-diameter ratio t between 0.20 and 0.40. The depth of the defect is accurately detected. It solves the technical problem of ultrasonic detection of the depth of internal defects of ultra-thick-walled pipes, and has high economic and social benefits.

Description

technical field [0001] The invention relates to the technical field of detection of thick-walled pipes, in particular to a three-dimensional positioning method for ultrasonic detection of internal defects of thick-walled pipes. Background technique [0002] Thick-walled pipes are widely used in electric power and petrochemical industries, and the use environment is harsh. During the manufacturing process of thick-walled pipes, they generally go through processes such as smelting, forging, heat treatment, and mechanical processing. During the manufacturing process, thick-walled pipes often have internal defects mainly distributed in radial and longitudinal directions. 100% ultrasonically tested. However, during the detection process of ultra-thick-walled pipes with a thickness-to-diameter ratio t between 0.20 and 0.40, because the incident angle to be adopted is too small, there will be refracted transverse waves and refracted longitudinal waves inside at the same time. It ...

AI Technical Summary

Problems solved by technology

However, during the detection process of ultra-thick-walled pipes with a thickness-to-diameter ratio t between 0.20 and 0.40, because the incident angle to be adopted is too small, there will be refracted transverse waves and refracted longitudinal waves inside at the same time. It is difficult to judge the wave type of the detected defect when the reflected wave of the defect is found, so it is difficult to accurately locate the depth of the defect, making it difficult to evaluate and dispose of thick-walled pipes, increasing the quality cost, and burying hidden dangers for subsequent use