Magnetic Particle Testing

There are several methods of magnetic particle testing to detect welding, casting and forging defects in iron and steel parts. The part to be tested is magnetised by external magnetic yoke coil or passing an electrical current and the inspection medium is applied on it.

In dry method of inspection, a special fine ferromagnetic powder is applied on the surface by means of hand shaker or vibrating screen so that the powder is uniformly distributed on the surface. In wet method, a liquid like kerosene containing suspended fine ferromagnetic particles is sprayed or brushed. Due to the formation of magnetic poles at the crack or flaw, the magnetic powder concentrates in that area.