Magnetic particle inspection is technically used to measure cracks on the surface of the mill roll body and fatigue cracks in the mill roll neck area, excessive cycle time loading, or subsequent normal corrosion caused by all.
The principle of magnetic particle inspection: the principle of electromagnetic field theory, the amount of magnetized current generates a magnetic field according to the surface of the workpiece of ferromagnetic material products, the appearance of defects will break the magnetic field lines, generate leakage electromagnetic field and attract the magnetic powder, magnetic powder deposition produces magnetic marks, carefully observe the magnetic marks to distinguish the presence of defects (magnetic marks are essentially enlarged defects).
The technical advantages of magnetic particle inspection:
(1) Identify surface and subsurface linear discontinuities;
(2) The actual operation and expression are relatively simple.
Magnetic particle inspection technical defects:
(1) Only applied to ferromagnetic materials;
(2) Flaw detection is limited to surface defects.