MFL flaw detection, magnetic flux leakage flaw detection, residual magnetic flaw detection
When the ferromagnetic steel pipe is fully magnetized, the magnetic lines of force in the pipe wall are blocked by defects on or near the surface, and the magnetic lines of force at the defects are distorted. Part of the magnetic lines of force leak out of the inner and outer surfaces of the steel pipe, forming a leakage magnetic field. The electromagnetic detection method that uses detection elements to detect leakage magnetic fields to find defects is called leakage magnetic flaw detection. When the detection element located on the surface of the steel pipe and moving relative to the steel pipe picks up the leakage magnetic field and converts it into a defect electrical signal, the signal reflecting the defect can be obtained through the probe, so as to determine and process the defect.
Advantages: high degree of detection automation, fast detection speed, low cost, and easy operation. Disadvantages: The detection sensitivity is the highest on the outer surface, and decreases from the outside to the inside as the wall thickness increases; there is a blind area at the end of the pipe.
Commonly used for the production and manufacturing process of medium and large diameter steel pipes or to replace water pressure items.
