Investigations of magnetic flux leakage and magnetic Barkhausen noise signals from pipeline steel
- 21 March 1997
- journal article
- Published by IOP Publishing in Journal of Physics D: Applied Physics
- Vol. 30 (6), 962-973
- https://doi.org/10.1088/0022-3727/30/6/009
Abstract
Magnetic flux leakage (MFL) is used for in-line inspection of underground oil and gas pipelines. MFL signals are sensitive to the line pressure which should be taken into account when estimating the sizes of defects. MFL signals have been studied from electrochemically milled pits with 50% penetration in pipeline steel under the influence of different axial or circumferential stresses and a range of magnetic flux densities. Magnetic Barkhausen noise (MBN) measurements have been used to study the changes in the direction of the magnetic easy axis of the pipe wall. These help one to understand the stress-dependent MFL results. MBN measurements have also been used to estimate the directional magnetic anisotropies of the steels.Keywords
This publication has 6 references indexed in Scilit:
- Calculations of the effects of anisotropy on magnetic flux leakage detector signalsIEEE Transactions on Magnetics, 1996
- Variation of the stress dependent magnetic flux leakage signal with defect depth and flux densityNDT & E International, 1996
- Investigation of the stress-dependent magnetic easy axis in steel using magnetic Barkhausen noiseJournal of Applied Physics, 1996
- Characterization of the magnetic easy axis in pipeline steel using magnetic Barkhausen noiseJournal of Applied Physics, 1994
- Magnetic properties of decarburized steels: An investigation of the effects of grain size and carbon contentIEEE Transactions on Magnetics, 1987
- The magnetic leakage field of surface-breaking cracksJournal of Physics D: Applied Physics, 1986