Basic knowledge of magnetic particle flaw detector
1. According to the magnetization direction of the workpiece, it can be divided into circumferential magnetization method, longitudinal magnetization method, composite magnetization method and rotating magnetization method.
2. according to the different magnetizing current can be divided into: DC magnetization method, half-wave DC magnetization method, and AC magnetization method.
3. According to the preparation of magnetic powder used in the flaw detection, it can be divided into dry powder method and wet powder method.
Principle of magnetic particle inspection
Its basic principle is: when the workpiece is magnetized, if there is a defect on the surface of the workpiece, magnetic leakage occurs due to the increase of the magnetic resistance at the defect, and a local magnetic field is formed, and the magnetic powder shows the shape and position of the defect here, thereby judging the defect. The presence.