Ultrasonic flaw detection is an advanced method of inspecting parts for defects. It mainly uses the characteristics of ultrasonic energy penetrating into the depths of metal materials, and judges whether there is a defect through the reflection that occurs at the edge of the interface when the section enters another section. This flaw detection method can effectively judge the defect location and size through the pulse waveform.
The sound source generates ultrasonic waves, and the ultrasonic waves enter the specimen in a certain way. Ultrasonic waves propagate in the test piece and interact with the material of the test piece and the defects in it, changing its propagation direction or characteristics. The altered ultrasound is received by the detection device and can be processed and analyzed. Based on the characteristics of the received ultrasonic waves, the test piece itself and its internal defects are evaluated for the presence and characteristics of defects.
It is suitable for non-destructive testing of various parts such as metal, non-metal and composite materials. It has strong penetrating ability and can detect the internal defects of the test piece in a large thickness range. For metal materials, it can detect thin-walled pipes and plates with a thickness of 1-2mm, and can also detect steel forgings with a length of several meters. The defect location is more accurate, the regional defect detection rate is high, and the sensitivity is high. It can detect defects with small internal dimensions of the test piece. , The detection cost is low, the speed is fast, the equipment is light, harmless to the human body and the environment, and the on-site use is more convenient.
The limitations of ultrasonic testing for the precise determination and quantitative defects of the test pieces still need to be further studied. It is difficult to perform ultrasonic testing on samples with complex or irregular shapes. The defect position, orientation and shape have a certain influence on the detection results. Material and grain size have a great influence on the detection. The commonly used manual A-type pulse reflection method shows The results are not intuitive, and the test results cannot directly witness the record.