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Good morning to all members! We currently are in a PPAP process from a new supplier and they have asked if the bar stock ( 1043 ) needs to be demagnetized? I've never heard anything of this before as we aren't a steel processing plant. We are a manufacturing facility so usually don't get involved at this aspect of the product or its development.

Are there pros and cons of having it demagnetized ? We are an induction heat treat process so which would be a better material for us?

Any insight would greatly help us in this decision as we want to learn from this going forward.

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Rodney Recore
Plant Process Metallurgist
Brunner International
Gasport NY
(716) 998-9823
(585) 798-6000 ext 262
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If the customer is running nondestructive testing such as Eddy Current, then it is necessary to have the work piece demagnetized. We do it for surface anomaly detection. Hope it answers your question.

Regards,

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Sanjay Kulkarni
Materials Engineer
MSSC
2040 Crooks RD, Suite A
Troy, MI 48084
sanjay.kulkarni@msscna.com
Cell: 248-840-1056
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Bar stock that has been heated above the Curie temperature and allowed to cool in the absence of a strong magnetic field should not have significant magnetization.  Other processes, such as cold rolling and machining, can leave low levels of magnetism which are usually neglected.  If you are performing induction heat treatment, you are inducing fields into the part, which if in an area that didn't get red hot, might remain.  I'd ask the customer if they have a minimum level of magnetization that is important, and then perhaps you should decide if you want to add cost to your process by including magnetic measurement as a one-time thing or as an ongoing material certification.  And if you want to do the test, then there are relatively inexpensive measurement tools to check the remanent magnetic fields.  Contact any NDE supplier for those.

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Paul Tibbals
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