In a rotating-magnetic-field-type magnetizer using a three-pole (three-phase) coil, omnidirectional cracks can be detected via a single test. However, the rotating magnetic field ultimately experiences non-homogeneous distribution in an area far from the centre of the magnetizer. In this study, a multi-coil-type magnetizer that widely obtains uniform rotating magnetic fields was hence developed. Distributions of rotating magnetic flux densities in test object were evaluated using finite-element analysis, and the utility of the multi-coil was confirmed. In addition, the technique for omnidirectional magnetization on whole surfaces of 3D-shaped test object was considered via implementation of the subject multi-coil magnetizer.
International standard ISO9934-1 Non-destructive testing - Magnetic particle testing- part1 General principles (2001).
2.
RagusaC. and FiorilloF., A three-phase single sheet tester with digital control of flux loci based on the contraction mapping principle, Journal of Magnetism and Magnetic Materials304(2) (2006), e568-e570.
3.
AnganiC.S., KimJ., LeM. and LeeJ., Magnetic leakage testing using linearly integrated hall and GMR sensor arrays to inspect inclusions in cold-rolled strips, IEEE Trans. Magn.50(11) (2014), art. no. 6971599.
4.
BartoloJ.B., KlimczykP., TiwisinaK., DenkeP., SiebertS. and GeradaC., An investigation into the geometric parameters affecting field uniformity in four pole magnetisers, Int. J. of Appl. Electromagn. Mech.48(2-3) (2015), 225-232.
5.
FukuokaK., HashimotoM., AkamatsuS. and OikawaY., Evaluation of magnetic flux density distribution in rotating field type magnetic-particle testing using three-phase AC, Journal of JSNDI 58(3) (2009), 102-107. (in Japanese)
6.
FukuokaK., KawagoeI., OzakiT., IwataM., KumetaM. and OikawaY., Development of magnetic-particle testing magnetizer for generation of uniform rotating magnetic field in wide area, Journal of JSAEM 23(1) (2015), 118-124. (in Japanese)
