Magnetic suspension concentration refers to the amount of magnetic powder in grams contained within the carrier liquid. When the inspection device magnetizes the workpiece, if there are defects on the surface, a leakage flux occurs due to the increased magnetic resistance at the defect location, creating a local magnetic field. The magnetic powder then reveals the shape and position of the defect here, enabling the determination of its presence. Magnetic particle inspection devices can be classified based on the type of magnetization current used: direct current magnetization, half-wave direct current magnetization, and alternating current magnetization. The inspection machine displays the surface and internal defects of the parts and welds processed from the material to evaluate the quality of the product. It shows the location, shape, and size of discontinuities, capable of detecting extremely fine cracks, hairline cracks, white spots, folds, inclusions, and other defects on the material surface. It boasts a high detection sensitivity and can visually display the location, shape, size, and severity of the defects, with good repeatability in defect inspection.
If the application of the continuous magnetization wet method is approved, it should have well-controlled magnetization time. If there is a significant time difference in the terms, it will also affect it. Typically, it needs to stay for 2-3 seconds, as too short a time will reduce sensitivity overall and affect the required applications. When using the magnetization magnetic suspension spraying method, it can effectively improve detection.
Many inspection methods for flaw detectors will utilize the MPI ultraviolet lamp heat source. The following issues should be noted when using the light: it can communicate with the power source in simultaneous operational states, but it cannot guarantee its own time stability within a short period. Generally, the power will reach a stable state after 5 minutes, in other words, they can only work after the power has been on for over five minutes before testing.
Non-magnetic powders in various colors and types, such as black, red, and silver, are used in flaw detectors to reveal surface and internal defects in parts and welds made from the material, assessing the quality of the product. The magnetic particle flaw detector identifies the location, shape, and size of discontinuities, capable of detecting extremely fine cracks, hairlines, white spots, folds, inclusions, and other defects on the material surface with high sensitivity. It can visually display the location, shape, size, and severity of defects, ensuring good repeatability in defect inspection. Widely applied in tube, bar, profile, welded, machined, and forged material inspection, the flaw detector plays a unique role, especially in the regular inspections of pressure vessels and bearings. When the workpiece is magnetized, if there are defects on the surface, the increased magnetic resistance at the defect location causes leakage flux, creating a local magnetic field. The magnetic particles in the flaw detector then reveal the shape and position of the defects, thereby determining their presence.
Magnetic particle inspection devices can be categorized based on the type of magnetizing current used: direct current magnetization, half-wave direct current magnetization, and alternating current magnetization. Therefore, when purchasing magnetic iron powders for direct application, such as black magnetic, red, or white magnetic powders, or magnetic powders for enhancing the color contrast and visible clarity of images in magnetic marking applications, as well as for coloring the workpiece surface with white light, the selective magnetic powders are chosen. Additionally, the color of the workpiece surface can be selected, including whitening the workpiece surface with magnetic black, red magnetic powders, and black or white magnetic powders, as options.