Short solenoid/electromagnet cores - permeability, annealing, sources
Short solenoid/electromagnet cores - permeability, annealing, sources
(OP)
I'd really appreciate anybody's help on this.
Can anybody give me an idea of how big a deal not having hydrogen annealing is on effecting the magnetic permeability of a short solenoid core cut from steel 1018 rod? Core length is 7-10mm, core diameter is 10mm.
Also, does anyone happen to know an equation for the B of the above short solenoid, or alternatively have a recommendation for an FEA software trial? I'm assuming it's significantly different than that of a long solenoid: B=u0*urel * I * turns/length. I've looked for hours and can't find one.
Lastly, if I end up needing an annealed or some NiFe alloy core, can anybody recommend a source for small prototyping quantities?
Thanks so much, I haven't done any magnetics design before.
Scott
Can anybody give me an idea of how big a deal not having hydrogen annealing is on effecting the magnetic permeability of a short solenoid core cut from steel 1018 rod? Core length is 7-10mm, core diameter is 10mm.
Also, does anyone happen to know an equation for the B of the above short solenoid, or alternatively have a recommendation for an FEA software trial? I'm assuming it's significantly different than that of a long solenoid: B=u0*urel * I * turns/length. I've looked for hours and can't find one.
Lastly, if I end up needing an annealed or some NiFe alloy core, can anybody recommend a source for small prototyping quantities?
Thanks so much, I haven't done any magnetics design before.
Scott





RE: Short solenoid/electromagnet cores - permeability, annealing, sources
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RE: Short solenoid/electromagnet cores - permeability, annealing, sources
If the frequency is low (or DC) the initial perm is not a big deal, and the actual perm over a wider range will likely not be very different.
And if the material was reasonably well annealed after being rolled then it will have decent properties.
If one or both of these conditions is not met then I would look for a better material and a better heat treatment.
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P.E. Metallurgy, Plymouth Tube
RE: Short solenoid/electromagnet cores - permeability, annealing, sources
RE: Short solenoid/electromagnet cores - permeability, annealing, sources
Thanks EdStainless on the annealing info, very helpful!
RE: Short solenoid/electromagnet cores - permeability, annealing, sources
As far as the importance of the anneal, it all depends on what you are doing with this solenoid. Since you are using rather high carbon core material it can make a difference, particularly on remanance/coercive force. You could just use a better quality material. You can also do a vacuum anneal, it's nearly as good as a hydrogen anneal but won't pull the carbon out the way hydrogen will.
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