Ultrasonic flaw detection method of surfacing steel pipe from base material side

Abstract

The invention discloses an ultrasonic flaw detection method of a surfacing steel pipe from a base material side. The method is characterized by comprising a single straight probe detection from the base material side of the pipe and a phased array detection from the base material side of the pipe, wherein the single straight probe detection comprises using a single straight probe, correcting base line by using a flat-bottomed hole and a bottom echo, correcting and detecting sensitivity by using the flat-bottomed hole, so that echo of artificial flat-bottomed hole can reach 80 %; confirming scanning sensitivity of workpieces; and scanning the workpieces by using the single straight probe; and the phased array detection comprises selecting a phased array flaw detector and selecting probe and curvature wedge; correcting the phased array flaw detector and the probe and selecting a sector scanning and calibrating block; and scanning the workpieces by using the phased array detection. The method has characteristics of high flaw detection efficiency, accurate positioning, convenient repair, etc.

Description

technical field [0001] The invention relates to an ultrasonic flaw detection method for the parent metal side of a surfacing welded steel pipe, belonging to the technical field of nondestructive testing. Background technique [0002] In order to enhance the corrosion resistance of pipelines and prevent hydrogen corrosion and corrosion under the premise of cost control, it is required to surfacing a layer of material different from the parent material on the inner surface of the pipeline, that is, the surfacing layer. Surfacing materials are generally stainless steel or nickel-based alloys, etc. For quality control, the surface quality is generally checked by penetrant testing, and the internal quality is checked by ultrasonic testing. [0003] The defects of the surfacing layer can be divided into four categories according to the location of occurrence: ① Surface defects, including cracks, pores, slag inclusions, etc.; ② Defects in the surfacing layer, generally slag inclusi...

AI Technical Summary

Problems solved by technology

[0005] The purpose of the present invention is to solve the problem that the flaw detection cannot be carried out from the surfacing layer side when the pipe to be tested is very long, and to provide an ultrasonic flaw detection method on the base metal side of the surfacing welded steel pipe with high flaw detection efficiency, accurate positioning, and convenient repair