where expertise comes together - since 1996 -

The Largest Open Access Portal of Nondestructive Testing (NDT)

Conference Proceedings, Articles, News, Exhibition, Forum, Network and more

where expertise comes together
- since 1996 -

TWI
TWI is a global leader in technology engineering providing research and consultancy to its members in the field of materials and selection, joining, inspection, NDT and structural integrity management.

418 views
Technical Discussions
M.Kovacik
M.Kovacik
00:14 Oct-03-2004
UT and magnetic field

Dear colleagues

Recently,I have been confronted by a problem of UT testning steel material under strong magnetic fields. My question is : may magnetic fields produced by strong DC current (100kA) have any effect on the propagation and attenuation of 2MHz - 10 MHz ultrasonic waves?

Thanks for any answer.





    
 
 
Pim van Andel
Pim van Andel
02:32 Oct-06-2004
Re: UT and magnetic field
There could be some influence:
A DC field of this strength may magnetise a substantial volume of steel. Ultrasound passing through this volume generates eddy currents (compare the EMAT transducer principle)Energy loss by the eddy currents may attenuate the ultrasound.


----------- Start Original Message -----------
: Dear colleagues
: Recently,I have been confronted by a problem of UT testning steel material under strong magnetic fields. My question is : may magnetic fields produced by strong DC current (100kA) have any effect on the propagation and attenuation of 2MHz - 10 MHz ultrasonic waves?
: Thanks for any answer.
:
:
------------ End Original Message ------------




    
 
 
Chris Coughlin
Chris Coughlin
05:08 Oct-07-2004
Re: UT and magnetic field
If the field's strong enough, it can change the acoustic velocity of the steel, because of the stresses (e.g. magnetostriction) a magnetic field can induce in a ferromagnetic material. This "magnetoelastic effect" is sometimes used to measure stresses in ferromagnetic steels.

Hope this helps,
Chris

----------- Start Original Message -----------
: Dear colleagues
: Recently,I have been confronted by a problem of UT testning steel material under strong magnetic fields. My question is : may magnetic fields produced by strong DC current (100kA) have any effect on the propagation and attenuation of 2MHz - 10 MHz ultrasonic waves?
: Thanks for any answer.
:
:
------------ End Original Message ------------




    
 
 
Pim van Andel
Pim van Andel
02:11 Oct-08-2004
Re: UT and magnetic field
And the change in velocity is (much?) less then 1% ?

----------- Start Original Message -----------
: If the field's strong enough, it can change the acoustic velocity of the steel, because of the stresses (e.g. magnetostriction) a magnetic field can induce in a ferromagnetic material. This "magnetoelastic effect" is sometimes used to measure stresses in ferromagnetic steels.
: Hope this helps,
: Chris
: : Dear colleagues
: : Recently,I have been confronted by a problem of UT testning steel material under strong magnetic fields. My question is : may magnetic fields produced by strong DC current (100kA) have any effect on the propagation and attenuation of 2MHz - 10 MHz ultrasonic waves?
: : Thanks for any answer.
: :
: :
------------ End Original Message ------------




    
 
 
Chris Coughlin
Chris Coughlin
03:14 Oct-08-2004
Re: UT and magnetic field
Granted, the effect is small (delta V/V ~10^-5 normally), but the original question was "any effect," not "any significant effect." ;-)

Take care & have a good weekend!

--chris

----------- Start Original Message -----------
: And the change in velocity is (much?) less then 1% ?
: : If the field's strong enough, it can change the acoustic velocity of the steel, because of the stresses (e.g. magnetostriction) a magnetic field can induce in a ferromagnetic material. This "magnetoelastic effect" is sometimes used to measure stresses in ferromagnetic steels.
: : Hope this helps,
: : Chris
: : : Dear colleagues
: : : Recently,I have been confronted by a problem of UT testning steel material under strong magnetic fields. My question is : may magnetic fields produced by strong DC current (100kA) have any effect on the propagation and attenuation of 2MHz - 10 MHz ultrasonic waves?
: : : Thanks for any answer.
: : :
: : :
------------ End Original Message ------------




    
 
 

Product Spotlight

AIS229 - Multipurpose Real Time System

Latest standard & automatic real time system developed by Balteau. The AIS229 has been designed to
...
do series inspection in a wide variety of industry. Composed of a shielded cabinet, 5 axis manipulator, x-ray generator and tubehead from 160kV to 225kV, a fl at panel & much more, the AIS229 is most certainly one of the most multipurpose RTR system available on the market.
>

Exertus Dual 120

The Exertus Dual 120 Projector has the ability to accept Iridium 192 sources or Selenium 75 source
...
s. This projector incorporates design and safety features that make it flexible, compact and lightweight. The Projector is lighter than most of its competitors. It incorporates an improved source channel, based on a new helicoidal design, which makes maintenance easier. The helicoidal design also allows smoother movement of the source assembly inside the device, making it easier for the operator and improving safety. The Projector also has a unique safety feature not found in competitive products. The source assembly locking mechanism is triggered by the source holder capsule at the front of the source assembly, thereby always assuring the operator that the source has returned to the safe position. The Exertus Dual 120 is ISO3999:2004 compliant.
>

High Resolution Industrial CT System for Small/Medium Size Parts Inspection

The YXLON FF35 CT computed tomography system is designed to achieve extremely precise inspection res
...
ults for a wide range of applications. Available in a single or dual tube configuration, it is perfect for very small to medium size parts inspection in the automotive, electronics, aviation, and material science industries.
>

Varex Imaging Large Field of View (FOV) Digital Detector Arrays (DDAs)

A larger FOV DDA can reduce the space and volume of the X-ray inspection system on the factory floor
...
, enable faster scanning times, better throughput and better resolution images at a lower dose. Customers can also save time and money. With these benefits in mind, Varex Imaging has designed a family of large FOV detectors (4343HE, XRD 1611, 4343DX-I, 4343CT) for our industrial imaging customers.
>

Share...
We use technical and analytics cookies to ensure that we will give you the best experience of our website - More Info
Accept
top
this is debug window