Transverse wave detection method for defects of spiral weld steel pipe body and flaw detection apparatus used in same

Abstract

The invention discloses a transverse wave detection method for defects of a spiral weld steel pipe body and a flaw detection apparatus used in the same, belonging to the field of ultrasonic nondestructive flaw detection. According to the detection method, defects on the surface of a steel pipe and defects of welds are detected through transverse wave probes which are arranged between two spiral welds and perpendicular to the welds, and it is guaranteed that a detection area reaches 100%. The flaw detection apparatus comprises a freely elevating probe rack and basic detection units; a cross bar is fixedly arranged in the probe rack, a pair of the basic detection units are sleeved on and connected with the cross bar; the basic detection unit comprises a transverse adjusting means, a probe elevating means, a fixed base and a probe, wherein one end of the transverse adjusting means is sleeved on and connected with the cross bar, the other end of the transverse adjusting means is connected with the probe elevating means, telescoping connecting rods are arranged in the probe elevating means, and the end of the connecting rods is connected with the fixed base used for fixing the probe. According to the invention, distances among and elevating height of the probes can be flexibly adjusted, complete overlapping of the probes and the welds is guaranteed, flaw detection errors are reduced, and a detection level is improved.

Description

technical field [0001] The invention relates to a shear wave detection method for defects of a spiral welded steel pipe body and a flaw detection device thereof, which belong to the field of ultrasonic nondestructive flaw detection and are used in the ultrasonic detection process of a base material of a spiral seam submerged arc welded pipe. Background technique [0002] In order to ensure the quality of submerged arc welded steel pipes, the use of ultrasonic automatic flaw detection is a very economical and effective means to inspect and control the weld quality of spiral submerged arc welded pipes, and it is also a necessary detection method for the production of important pipelines in recent years. [0003] The principle of automatic flaw detection for spiral pipes is that two rows of weld probes are arranged symmetrically on both sides of the space helical curve weld. After the control system analysis, the defect shape is delineated. [0004] In general production pract...

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Problems solved by technology

[0005] In the process of automatic flaw detection, in order to ensure that all the weld probes fall on the steel pipe and accurately bridge the outer wall of the steel pipe, the weld probe holder is mostly designed as a space plate shape or a connecting rod structure. When the diameter and wall thickness of the spiral pipe change, the probe should be adjusted The distance between the probe and the lifting angle, the current structure of the weld probe frame can only be adjusted for a simple distance, so the probe and the outer wall of the steel pipe cannot be guaranteed to be completely bridged, thereby increasing the flaw detection error, and it is difficult to eliminate

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