Ultrasonic flaw detector how to detect internal defects in metal materials - Database & Sql Blog Articles

Ultrasonic flaw detector

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The injury is a way to reflect the defects of the part when the ultrasonic energy penetrates into the depth of the metal data and enters the other section from one section to the other. When the ultrasonic beam passes from the probe to the metal from the external part of the part Internally, when the defect and the bottom surface of the part are touched, the attack wave is discriminated, and a pulse waveform is formed on the screen, and the defect position and the size are determined based on the pulse waveform. The non-destructive inspection method for the internal defects of the data is checked by the influence of the acoustic function difference of the applied data and its defects on the ultrasonic transmission. At present, the ultrasonic pulse reflection method for observing the reflection state of the acoustic pulse in the data is commonly used, and there is also a penetration method for observing the amplitude transition of the incident acoustic wave after passing through the data. Commonly used frequencies are between 0.5 and 5 MHz. The commonly used inspection instrument is a type A display pulse reflection type ultrasonic flaw detector. According to the presence or absence of the reflected signal on the instrument oscilloscope, the distance between the reflected signal and the incident signal, and the height of the reflected signal, the presence or absence of the reflective surface, its location and relative size can be determined. Ultrasonic waves are transmitted in a variety of modes, and the most commonly used ones are longitudinal waves, transverse waves, surface waves, and plate waves. Longitudinal waves can be used to detect defects such as inclusions, cracks, shrinkage, white spots, delamination, etc. in metal ingots, billets, plate, large forgings and simple-shaped parts; Circumferential and axial cracks, scratches, pores in the weld, slag inclusions, cracks, incomplete penetration, etc.; external waves can be used to detect external defects on the shape of the part; defect.