Ultrasonic and Radiographic examination of Wear resistant Castings

- Dec 01, 2018-

X-ray inspection of wear-resistant castings

The wear-resistant castings usually use X-ray or γ -ray as the ray source, so the equipment and other ancillary facilities need to produce the rays. When the workpiece is exposed to the radiation field, the radiation intensity of the castings will be affected by the internal defects of the casting. The intensity of radiation emitted through the casting varies locally with the size and properties of the defect, forming a radiographic image of the defect, which is recorded by a radiographic film, or detected in real time by a fluorescent screen. Or through radiation counter detection.


Among them, the method of recording by radiographic film imaging is the most commonly used method, that is, radiographic detection, the defect image reflected by radiography is intuitive, the shape, size and quantity of the defect. The plane position and distribution range can be presented, but the depth of defects can not be reflected generally. Special measures and calculation are needed to determine the depth of defects.


Ultrasonic testing of wear-resistant castings


The main advantages of ultrasonic detection are: high detection sensitivity, can detect small cracks, with large penetration ability, can detect thick section castings. The main limitations lie in: the difficulty in interpreting the reflective waveforms of disconnected defects with complex contour size and poor directivity; The waveform interpretation is also obstructed by undesirable internal structures, such as grain size, microstructure, porosity, inclusion content or fine dispersed precipitates. In addition, reference standard test blocks are required for detection.