Ultrasonic TOFD (Time of Flight Diffraction) detection method for T-shaped welding joint

Abstract

The invention discloses an ultrasonic TOFD (Time of Flight Diffraction) detection method for a T-shaped welding joint and relates to the field of ultrasonic waves. The ultrasonic TOFD detection method comprises the following steps of: determining the distance between every two sound incident points according to the right-angled side size of a welding angle of the detected T-shaped welding joint, the thickness of a wing plate, the thickness of a web slab and a diffuse angle of a TOFD probe; before scanning, making two scanning path lines on the wing plate symmetrical to a central line of the weld joint, wherein the spacing is the difference of the distance between every two sound incident points and the summation of front edges of two ultrasonic probes; during detection, scanning along the scanning path lines on the wing plate of the T-shaped welding joint by a probe wedged block to generate a scanning image D; and analyzing the image to obtain the internal defect characteristics of the T-shaped welding joint. According to the ultrasonic TOFD detection method disclosed by the invention, the problems that the detection efficiency and the defect detection rate are low because the detection of the T-shaped welding joint specified in the traditional detection standard is only carried out through scanning by ultrasonic wave A are solved.

Description

Technical field: [0001] The invention belongs to the field of ultrasonic detection and relates to an ultrasonic TOFD detection method for T-shaped welded joints. Background technique: [0002] Ultrasonic Time of Flight Diffraction (Time of Flight Diffraction) method, referred to as TOFD, mainly locates and quantifies defects based on the time difference between the diffraction signals generated at the end of the defect, and is currently mainly used in the inspection of butt welds, NB / T4730.10- 2010 "Non-destructive Testing of Pressure Equipment Part Ten: Ultrasonic Testing by Diffraction Time Difference Method" stipulates that the TOFD method is suitable for butt joints with a wall thickness of 12mm ~ 400mm, a material of carbon steel or low alloy steel, and a full penetration structure. The TOFD test of T-shaped welded joints has not been stipulated. The European standard ENV583-6 and ASME standard of TOFD test method does not stipulate the TOFD of T-shaped welded joints. At pre...

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Problems solved by technology

[0003] In order to overcome the inability of the existing TOFD detection technology to detect T-shaped welded joints, the present invention proposes a TOFD detection method for T-shaped welded joints. By this method, the distance between the probes is determined, and by analyzing the reflected wave near the T-shaped joint welding toe and its The following signal characteristics can quickly and effectively find defects in T-shaped welded joints

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