MAGNETIC FLUX LEAKAGE TECHNOLOGY IN NDT
Magnetic Flux Leakage (MFL) nondestructive test systems accurately detect defects in heavy-wall magnetic tubing, including oil country tubular goods (OCTG).
These electromagnetic test methods are also used to inspect high-permeability ferromagnetic metals such as carbon steel bar, plate, wire rope and parts. The method can also be used to detect ferritic inclusions in non-ferritic material.
- For typical OCTG and other heavy wall tube tests, Flux Leakage technology detects longitudinal and transverse defects as small as 5% on OD and ID, as well as defects within the wall, depending upon material type and condition.
- MFL inspection uses a DC magnetizing field to create enough flux density to bring the material to near-saturation. A transverse magnetizing field is used to detect longitudinally oriented defects, while a longitudinal field is used to find transverse defects.
- Surface or internal conditions such as cracks, pits, seams and other defects interrupt the flux field and “leak” beyond the product surface.
- This leakage flux is detected by flux sensor probes with MAC configured rotary inspection devices which can wirelessly transmit this data to the instrumentation for processing and analysis.