Ultrasonic detection method for defects of welding position of through-wall pipe of peak shaving unit

Abstract

The invention relates to an ultrasonic detection method for defects of a welding position of through-wall pipe of a peak shaving unit, and belongs to the field of nondestructive detection. The methodcomprises the steps: manufacturing a test block by utilizing the same batch of original pipes of a to-be-detected through-wall pipe; designing a detection probe with radian, adjusting the sensitivityby using the test block, and determining an AVG curve and a DAC curve; selecting a K1 probe and detecting the K1 probe by using a secondary wave; selecting a K2 probe and detecting by using a primarywave; selecting a creeping wave probe to detect the butt weld of the through-wall pipe, and detecting the weld at the joint of the defective through-wall pipe and the sleeve to judge whether the defect is expanded to the wall of the through-wall pipe or not; and performing analysis to obtain a detection result. The method has the advantages of being capable of effectively detecting the defects ofthe welding positions of the through-wall pipes such as the peak shaving unit heating surface pipe, accurate in detection result, not prone to missing detection, capable of solving the problem of defect detection of the welding seams of the through-wall pipes of a peak shaving unit reheater and capable of guaranteeing safe operation of a power generation boiler of a thermal power plant.

Description

technical field [0001] The invention belongs to the field of non-destructive testing, and in particular relates to an ultrasonic detection method for the installation and operation defects of the wall-pipe sealing weld seam of a reheater of a peak-shaving unit, which is used for detecting the defects of the welding part of the wall-pipe such as the heating surface pipe of the peak-shaving unit. Background technique [0002] Thermal power plant boilers are designed with wall-piercing pipes, which usually have an operating temperature above 550°C. In order to avoid damage to the pipes caused by the vibration of these pipes during operation, the wall-piercing pipes are usually welded and fixed with sleeves. Due to the limited welding position, original defects such as lack of fusion, incomplete penetration, and cracks may occur during welding; Defects occur at the seam position and extend downward along the weld. If the defect cannot be found and dealt with in time, leakage wi...

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Problems solved by technology

[0003] The present invention provides an ultrasonic detection method for defects in the welded part of the wall-piercing pipe of the peak-shaving unit to solve the problem of defect detection at the weld of the wall-piercing pipe of the reheater of the peak-shaving unit

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