Phased array detection method for fillet weld of pipe base

Abstract

The invention discloses a phased array detection method for a fillet weld of a pipe base. The method comprises the following steps: drawing weld graphic expressions corresponding to different angles; connecting a probe with a phased array ultrasonic test instrument; converting an ultrasonic beam into a scanning image by the phased array ultrasonic test instrument; introducing the weld graphic expressions corresponding to different angles into the phased array ultrasonic test instrument, converting the weld graphic expressions to a corresponding angle following the probe once moving the probe for a certain angle while detecting and then correspondingly matching the introduced graph with a practical S scanned image, thereby guaranteeing one-to-one correspondence of the detected signal wave and the weld graphic expressions; if the position of a generated echo is overlapped with a workpiece loading graph, confirming the echo as the echo generated at a workpiece boundary; if not, confirming the echo as the echo generated by defect. The detection data can be acquired after the probe is adhered to the workpiece and is used for scanning from a starting point to a destination, the detection efficiency is high and the time cost is saved. The defects of the fillet weld of the pipe base can be detected and the omission ratio is lower.

Description

technical field [0001] The invention relates to the technical field of nondestructive testing, in particular to a phased array testing method for fillet welds of pipe seats. Background technique [0002] The pressure-bearing parts of boilers and steam turbines in thermal power plants have been in working condition for a long time. With the increase of working life, under the action of corrosion and long-term alternating stress, it is likely that the structural stress concentration or defect of the fillet weld of the pipe seat will Cracks gradually form and leaks occur, and more seriously, it may cause the pipe seat to break, causing damage to the unit and resulting in shutdown accidents, which seriously threaten the safe operation of the power plant. [0003] The use of conventional ultrasonic detectors requires constant movement of the probe to detect workpieces, and it is difficult to judge defects from the detected waveform images. Therefore, there is a need for an ultra...

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Problems solved by technology

[0002] The pressure-bearing parts of boilers and steam turbines in thermal power plants have been in working condition for a long time. With the increase of working life, under the action of corrosion and long-term alternating stress, it is likely that the structural stress concentration or defect of the fillet weld of the pipe seat will Gradually form cracks and leaks, and more seriously, it may cause the pipe seat to break, cause damage to the unit and cause shutdown accidents, and seriously threaten the safe operation of the power plant

[0003] The use of conventional ultrasonic detectors requires constant movement of the probe to detect workpieces, and it is difficult to judge defects from the detected waveform images

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