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Are you already familiar with our industrial-grade accredited inspection services?

 Accredited laboratory in line with DIN EN ISO / IEC 17025, to qualify and validate new non足
destructive testing (NDT) processes for industrial applications

 Accelerated time-to-market and opportunity for qualified, norm-compliant deployment in
industrial applications as well as for complete new in-house developments or custom adaptation
of innovative NDT technologies, even in fields where norms have not been established

 Certification of the corresponding quality management system in accordance with
DIN EN ISO 9001
Fraunhofer-Institut f端r Zerst旦rungsfreie Pr端fverfahren IZFP
Campus E3 1
66123 Saarbr端cken
+49 681 9302 0
info@izfp.fraunhofer.de
www.izfp.fraunhofer.de
MAGNETIC FLUX LEAKAGE INSPECTION
Fraunhofer and IZFP
are registered trademarks.
猷W猷廊廊廊楼婁猷婁狼猷婁婁
F R A U N H O F E R I N S T I T U T E F O R N O N D E S T R U C T I V E T E S T I N G I Z F P
BetoFlux in action
息 Uwe Bellh辰user
Sensor arrays enable the fast inspection even of complex parts or flat samples (gears etc.). The process
is fully automated and is therefore also suitable for integration into production processes. For use in
construction and component testing mobile testing systems using the flux leakage testing can be
realized.
Application
The previous use of magnetic flux leakage inspection covers a wide range of applications:

 Crack detection in the field of the industrial production of ferromagnetic components (eg. after
induction hardening or after adjustment, figure 3)

 Detection of wire breaks in prestressed concrete poles by BetoFlux system (cover)

 Check for internal and external defects on pipelines for corrosion detection (figure 4)
For fast testing of the feasibility in the case of flat samples a demonstrator (FLUXI) was set up
(figure 5).
Situation
Steel components as used in machine construction, automotive industry and plant construction or
load-bearing steel assemblies as needed in building construction are exposed to high mechanical
loads that may cause crack-like defects during operation or even earlier during production process.
Besides cracks, corrosion induced defects can cause component failure, too. Thus, a defect inspection
immediately after manufacturing is mandatory, at least once.
For this purpose, in industrial production of ferromagnetic components or semifinished products
足
magnetic particle testing is used. This inspection method, indeed, works non-destructively, but the
procedure implicates high manpower requirements. One limitation of the method relates to its auto足
mation which is impeded by geometry influences, but above all, the magnetic powder accumulates
in any existing depressions. Thus, the contrast is deteriorated and, as a result the automatic detection
of the defect indication is impeded.
Similarly, in construction regular monitoring of the structural integrity is desirable. Especially in the
field of concrete structures non-destructive testing for corrosion and breakage detection is required. If
the areas at risk are covered (eg. concrete cover in reinforced concrete poles), at present the construc足
tion has to be impaired to expose the elements to be tested.
Solution
The magnetic flux leakage inspection is designed to detect crack-like surface defects and local
cross-sectional or wall thickness reductions in ferromagnetic materials. The method is based on the
same physical effect, which is exploited in the magnetic particle inspection: At sharp disruptions of
a component surface as well as in areas of smaller cross section, additional magnetic dipoles which
produce a near-surface magnetic flux leakage are formed on application of an external magnetic field
(figure 1). Highly sensitive magnetic field sensors, generally arranged in linear arrays (figure 2), are
manually or automatically headed over the inspection surface for detecting the magnetic flux leakage
in the area of possible defects.
1: Magnetic flux leakage  principle 2: Linear array of highly sensitive
magnetic field sensors
4: Corrosion inspection
3: Crack visualization after induction hardening
5: FLUXI in use on sheet steel wih test defect

More Related Content

magnetic flux leakage inspection-en.pdf

  • 1. Are you already familiar with our industrial-grade accredited inspection services? Accredited laboratory in line with DIN EN ISO / IEC 17025, to qualify and validate new non足 destructive testing (NDT) processes for industrial applications Accelerated time-to-market and opportunity for qualified, norm-compliant deployment in industrial applications as well as for complete new in-house developments or custom adaptation of innovative NDT technologies, even in fields where norms have not been established Certification of the corresponding quality management system in accordance with DIN EN ISO 9001 Fraunhofer-Institut f端r Zerst旦rungsfreie Pr端fverfahren IZFP Campus E3 1 66123 Saarbr端cken +49 681 9302 0 info@izfp.fraunhofer.de www.izfp.fraunhofer.de MAGNETIC FLUX LEAKAGE INSPECTION Fraunhofer and IZFP are registered trademarks. 猷W猷廊廊廊楼婁猷婁狼猷婁婁 F R A U N H O F E R I N S T I T U T E F O R N O N D E S T R U C T I V E T E S T I N G I Z F P BetoFlux in action 息 Uwe Bellh辰user
  • 2. Sensor arrays enable the fast inspection even of complex parts or flat samples (gears etc.). The process is fully automated and is therefore also suitable for integration into production processes. For use in construction and component testing mobile testing systems using the flux leakage testing can be realized. Application The previous use of magnetic flux leakage inspection covers a wide range of applications: Crack detection in the field of the industrial production of ferromagnetic components (eg. after induction hardening or after adjustment, figure 3) Detection of wire breaks in prestressed concrete poles by BetoFlux system (cover) Check for internal and external defects on pipelines for corrosion detection (figure 4) For fast testing of the feasibility in the case of flat samples a demonstrator (FLUXI) was set up (figure 5). Situation Steel components as used in machine construction, automotive industry and plant construction or load-bearing steel assemblies as needed in building construction are exposed to high mechanical loads that may cause crack-like defects during operation or even earlier during production process. Besides cracks, corrosion induced defects can cause component failure, too. Thus, a defect inspection immediately after manufacturing is mandatory, at least once. For this purpose, in industrial production of ferromagnetic components or semifinished products 足 magnetic particle testing is used. This inspection method, indeed, works non-destructively, but the procedure implicates high manpower requirements. One limitation of the method relates to its auto足 mation which is impeded by geometry influences, but above all, the magnetic powder accumulates in any existing depressions. Thus, the contrast is deteriorated and, as a result the automatic detection of the defect indication is impeded. Similarly, in construction regular monitoring of the structural integrity is desirable. Especially in the field of concrete structures non-destructive testing for corrosion and breakage detection is required. If the areas at risk are covered (eg. concrete cover in reinforced concrete poles), at present the construc足 tion has to be impaired to expose the elements to be tested. Solution The magnetic flux leakage inspection is designed to detect crack-like surface defects and local cross-sectional or wall thickness reductions in ferromagnetic materials. The method is based on the same physical effect, which is exploited in the magnetic particle inspection: At sharp disruptions of a component surface as well as in areas of smaller cross section, additional magnetic dipoles which produce a near-surface magnetic flux leakage are formed on application of an external magnetic field (figure 1). Highly sensitive magnetic field sensors, generally arranged in linear arrays (figure 2), are manually or automatically headed over the inspection surface for detecting the magnetic flux leakage in the area of possible defects. 1: Magnetic flux leakage principle 2: Linear array of highly sensitive magnetic field sensors 4: Corrosion inspection 3: Crack visualization after induction hardening 5: FLUXI in use on sheet steel wih test defect