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1985 views
03:59 Jan-16-2001

Uday Kale

Director, NDE Services, Inservice Inspection, ASME Code shop Level III Services, Training in NDE and API
KUB Quality Services Pvt. Ltd,
India,
Joined Apr 2000
8
Demagnetization requirement for AC yoke

Dear All,
Can somebody tell me that whether Demagnetization is required
when material is magnetized using AC current Yoke.
Material is D2 and Component is a Die Block and Inspection
is done after service.
It will be very nice if you can give me the reference for
the same,
Thanking you,

Uday Kale


 
09:49 Jan-16-2001
Nick Welland
Re: Demagnetization requirement for AC yoke : Dear All,
: Can somebody tell me that whether Demagnetization is required
: when material is magnetized using AC current Yoke.
: Material is D2 and Component is a Die Block and Inspection
: is done after service.
: It will be very nice if you can give me the reference for
: the same,
: Thanking you,

: Uday Kale

Yes, it is quite likely that an AC yoke will leave a residual field in a component, especially in a tool or die steel.
Fortunately the same yoke can usually demagnetize the workpiece by pulling it off the surface while still energized and withdrawing it to a fair distance before switching off. Always check with a field indicator before and after.
Most Standards have a requirement to demag if a residual field is detrimental to service or a subsequent manufacturing operation.
Regards
Nick


 


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