Small-diameter pipe phased array ultrasonic detection comparison test block and detection calibration method using same

Abstract

The invention discloses a small-diameter pipe phased array ultrasonic detection comparison test block. The small-diameter pipe phased array ultrasonic detection comparison test block comprises a middle pipe section (2) and calibration sections (1) and (3) at two ends, wherein an arc surface (4) is arranged at an end of each calibration section (1), and a through hole (5) is formed in the end of each calibration section (1); the axis of each through hole (5) is positioned on an extension surface of an inner hole of the middle pipe section (2); two long through holes (7) and (8) and a section ofarc-shaped groove (9) are formed in each calibration section (3); the axis of each long through hole (7) is positioned on an extension surface of an outer circle of the middle pipe section (2); and blind holes (10) and (11) are respectively formed in the outer circle and the inner hole of the middle pipe section (2); and the outer circle of the middle pipe section (2) is also provided with a section of arc-shaped groove (12). The invention also discloses a small-diameter pipe phased array ultrasonic detection calibration method. According to the invention, the influence of the inner wall andthe outer wall of a small-diameter pipe on reflection of an ultrasonic sound beam can be reflected, the consistency of the detection sensitivity of reflected wave at different times is ensured, the accuracy and the reliability of defect quantification are improved, and the risk of missing detection of point defects is reduced.

Description

technical field [0001] The invention relates to a comparative test block for ultrasonic detection and a detection and verification method, in particular to a comparison test block for phased array ultrasonic detection of small-diameter tubes and a detection and verification method using the test block. Background technique [0002] A large number of welded joints of small-diameter pipes (diameter <100mm) exist in boilers and pressure vessels. Phased array ultrasonic testing is an important means of quality inspection of small-diameter pipe welded joints. It has high detection efficiency, intuitive imaging, good applicability, digitalization, and Radiation and other advantages have gradually become the main method for quality inspection of small-diameter pipe welded joints under on-site conditions and complex structure welds, and has broad application prospects. In order to obtain an objective and unified evaluation of detected defects, before phased array ultrasonic testi...

AI Technical Summary

Problems solved by technology

Due to the small diameter and thin wall thickness of the small-diameter pipe, the same pipe diameter and wall thickness must be used for the test block. In order to overcome the limitations of the welding width and the size of the front of the probe and obtain better imaging resolution, in order to make the entire inspected weld area be compared The controlled-array ultrasonic sound beam covers the entire area, and the detection usually requires the use of secondary waves, tertiary waves, or quaternary waves that have undergone one or more reflections; while the inner wall of the small-diameter tube diverges the ultrasonic reflection, and the outer wall gathers the ultrasonic reflection Therefore, the weld defect signal detected by phased array ultrasound includes the comprehensive influence of inner wall scattering and outer wall aggregation, and the same defect detected by the secondary wave, third wave, and quaternary wave is affected by the comprehensive effect of inner wall scattering and outer wall aggregation. The impact is completely different, which may lead to a large error in the quantification of defects, especially for small-diameter tubes with a large wall thickness to outer diameter ratio.

The existing comparison test block for phased array ultrasonic testing of small-diameter tubes usually adopts a test block similar to GS horizontal through hole, such as figure 1 , figure 2 As shown, the end is provided with an arc surface 21, and a stepped hole 22 and two rows of transverse through holes 23, 24 are arranged inside. When testing, the probe is placed on the arc surface of the upper and lower ends of the test block and moved, and the probe is aligned with the arc. Surface 21 is used for the calibration of probe wedge delay time, leading edge size, and angle gain supplement. The probe is aligned with two rows of transverse through holes 23 and 24 for calibration and making DAC or TCG curves; this test block is convenient for calibration, but due to The overall shape is blocky, which cannot reflect the influence of the inner and outer walls of the tubular workpiece on the reflection of the ultrasonic beam, resulting in a large defect detection quantitative error, and only using the horizontal through hole to set the detection sensitivity, which cannot simulate point defects, which may easily lead to missed detection of harmful point defects

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