Intermediate and large diameter thin-wall pipe nondestructive detection method based on phased array ultrasonic flaw detector

Abstract

The invention discloses an intermediate and large diameter thin-wall pipe nondestructive detection method based on a phased array ultrasonic flaw detector. The method comprises the following steps: selecting a corresponding wedge and a corresponding probe according to a specification and thickness of a to-be-detected workpiece, fixing the wedge at a front end of the probe, and enabling the probe to connect with an encoder; determining a focusing rule according to an adopted scanning type, and clearing the revolved probe parameter and focusing rule parameter; demonstrating by using simulation software in the detection equipment, adjusting the distance between the front end of the probe and a welding seam edge; enabling the selected detection acoustic beam to cover all detection regions, anddetermining a location of a reference line; measuring by using a ruler according to a set distance between the probe and the welding seam in the focusing rule, and fixing a magnetic stripe at a measurement location to connect with the encoder probe which moves along the magnetic strip edge so as to perform welding seal detection; saving detection data, analyzing and processing the detection datato obtain a detection result, and labeling a defect location and defect type of an unqualified welding seam.

Description

technical field [0001] The invention relates to the technical field of thin-walled pipe detection, in particular to a non-destructive detection method for medium and large diameter thin-walled pipes based on a phased array ultrasonic flaw detector. Background technique [0002] At present, the detection of welded joints of pressure pipelines in power stations is mainly based on two detection methods: ray and conventional A-type ultrasonic detection methods. According to the requirements of the standard, the method of segmented transillumination is required for the pipe with an outer diameter greater than 89mm. Multiple transillumination takes a long time and is inefficient; in the DL / T820-2002 ultrasonic testing procedure, the medium and thick wall can be detected according to the standard Pipe (outer diameter ≥ 108mm, 14mm ≤ wall thickness ≤ 160mm or less), medium and small diameter thin-walled pipe (32mm ≤ outer diameter ≤ 159mm, 4mm ≤ wall thickness ≤ 14mm), for pipe diam...

AI Technical Summary

Problems solved by technology

[0004] There is ionizing radiation in conventional ray detection, which has certain harm to the human body and cannot be synchronized with construction

The procurement and filing procedures of radioactive sources are complicated, and there are high safety risks in storage and use management

In addition, the ray focal length has certain requirements. If the focal length is too short, the clarity of the film will be poor. On-site inspection of some welding joints is limited by conditions and cannot meet the requirements, resulting in the failure of ray inspection, and ray inspection cannot perform deep positioning of defects.

[0005] The results of conventional ultrasonic testing are not intuitive, and traceability records cannot be formed

The test results are affected by the technical operation level of the test personnel and the on-site working conditions

Some specifications of large and medium-diameter thin-walled pipes do not meet the requirements of electric power standards

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