Magnetic particle testingNon destructive metal testing Magnetic particle testing involves a non destructive method of testing to detect imperfections on top of the metal or below its surface. This is usually an easy and very reliable means of detecting and locating of faults such as cracks on metal’s surface.The procedure; a flux is ran through the material being tested; the location at which the imperfection is, a leakage field is formed, which attracts metal iron dust, which gets sprayed at the surface.
Sometimes there is a residual field left on the surface testing on welding materials which may interfere with welding. The residue fields can be removed by wiping the surface with an energized AC yoke; this has to be done softly not to scratch.Although the described method may not easily determine the depth of the imperfections of cracks, it is a very reliable way of determining the length of the same.The application of the magnet particle testing may be used on all ferrous metals including carbon steel, cast iron etc.It is mainly used in welds and zones affected by heat it may also be applied for low relatively dirty surfaces, rough surfaces although the sensitivity of flaw is usually decreased in the particular kind of surface.It is important to note that the use of fluorescent particles is encouraged when highest sensitivity is required.
