Application of Ultrasound in Practical Work of Weld Flaw Detector

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Application of Ultrasound in Practical Work of Weld Flaw Detector
After receiving the task of flaw detection, the first thing is to understand the technical requirements of the drawings for welding quality. Ultrasound is used in full penetration weld flaw detector. Its flaw detection ratio is calculated by the percentage of each weld length, and it is not less than 200 mm. For locally inspected welds, if there is an impermissible defect, the inspection length should be increased at the extension of both ends of the defect. The increase length should not be less than 10% of the length of the weld, and it should not be less than 200 mm. When there are still impermissible defects, 100% flaw detection should be carried out for the weld. Secondly, when using the weld flaw detector, the timing of flaw detection should be clear. Carbon structural steel should be tested after the weld cooling to the ambient temperature and low alloy structural steel can be tested 24 hours after the completion of welding. In addition, the thickness of base metal, joint type and groove type of the workpiece to be measured should be known in use. Generally, the base metal thickness of weld flaw detector is between 8 and 16 mm. The groove type includes I type, single V type and X type. The preparatory work before flaw detection can be carried out only after making clear the above.