MAGNETIC
PARTICLE INSPECTION
The
most common NDT is Magnetic Particle Inspection, which uses a magnet (110v.
or 12 v.) on magnetic materials. The subject area is magnetized and then either
sprayed with a florescent liquid material and viewed under a black light,
or dusted with a colored dry powder.
This NDT method is accomplished by inducing a magnetic field in a ferromagnetic material and then dusting the surface with iron particles (either dry or suspended in liquid). Surface and near-surface flaws produce magnetic poles or distort the magnetic field in such a way that the iron particles are attracted and concentrated. This produces a visible indication of defect upon the surface of the material.
The first step in a magnetic particle inspection is to magnetize the component that is to be inspected. If any defects on or near the surface are present, the defects will create a leakage field. After the component has been magnetized, iron particles, either in a dry or wet suspended form, are applied to the surface of the magnetized part. The particles will be attracted and cluster at the flux leakage fields (increased magnetic flux above the surface of a part due to a crack near the surface), thus forming a visible indication of the presence of a crack or some other imperfection in the part being inspected.
The
most common NDT is Magnetic Particle Inspection, which uses a magnet (110v.
or 12 v.) on magnetic materials. The subject area is magnetized and then either
sprayed with a florescent liquid material and viewed under a black light,
or dusted with a colored dry powder.This NDT method is accomplished by inducing a magnetic field in a ferromagnetic material and then dusting the surface with iron particles (either dry or suspended in liquid). Surface and near-surface flaws produce magnetic poles or distort the magnetic field in such a way that the iron particles are attracted and concentrated. This produces a visible indication of defect upon the surface of the material.
The first step in a magnetic particle inspection is to magnetize the component that is to be inspected. If any defects on or near the surface are present, the defects will create a leakage field. After the component has been magnetized, iron particles, either in a dry or wet suspended form, are applied to the surface of the magnetized part. The particles will be attracted and cluster at the flux leakage fields (increased magnetic flux above the surface of a part due to a crack near the surface), thus forming a visible indication of the presence of a crack or some other imperfection in the part being inspected.
