【Summary】For the internal defects in iron castings, there will be non-destructive testing methods, including the radiographic inspection and ultrasonic inspection and measurement. Among them, the effect of the radiographic inspection is best. It can reflect the type and shape of internal defects, and can also reflect the visual images of the size and distribution.
However, for large castings of large thickness, the ultrasonic inspection and measurement will be very effective. Because of this, it can measure the position of the internal defect more accurately to a great extent and can its own equivalent size and distribution.
On the other hand, the inspection of internal defects in iron castings can also be carried out by radiographic means. In general, an x - ray or a γ- ray can be directly used as a radiographic source. Because of this, for equipment and other ancillary facilities that need to produce the ray, when the workpiece is exposed to the radiation field, the radiation intensity will be directly affected by the internal defects of the casting.
Accompanied by the difference of the size and property of the defects, the radiation intensity radiated through the iron castings, to a great extent, will have local change. in this way, it will directly form the defect ray image.
In this way, the defects in iron castings, to a large extent, will be directly recorded through the radiographic film. Then, to a great extent, the real-time detection will be carried out through the fluorescent screen. Furthermore, the internal defects in the iron castings can be directly detected by the radiation counter. The more accurate the detection is, and the better the quality will be.