Permeability attainable in cold-worked Austenitic Stainless Steel 1

[zmrs03]

A device using a Hall effect sensor and magnet for position sensing also uses springs made from type 304 Stainless steel, which are sufficiently cold worked to be attracted to a magnet. My task is to perform magnetic FEA to characterise the device, and my questions are twofold:

First, what is the limit of relative permeability that is attainable through cold working of type 304 steel, and

Second, is B-H curve data available anywhere for cold-worked austenitic stainless steel?

Enlightenment on these items would be greatly appreciated.

Thanks,
Mike.

 

[swall]

Can't help you for 304 ss, but for 302 spring temper wire,the permeability is listed as >12 at 200 Oersted, room temperature, in the SMI spring design book.

 

[EdStainless]

For 304 tubing we see values ranging from <1.02 to about 2. It depends greatly on the amount of cold work and the specific composition.
If I have 8.5% Ni and 0.08% N2, I can get 120-140 ksi tensile strength with <1.05 easily.
If the Ni is 8.0% and the nitrogen is 0.05%, I can draw to 150ski min and have at least a perm of 2.

I don't think that there is a generic answer for you.

= = = = = = = = = = = = = = = = = = = =
Corrosion, every where, all the time.
Manage it or it will manage you.

http://www.trent-tube.com/contact/Tech_Assist.cfm

 

[Kenneth]

Interesting magnetic permeabiltiy data on the bottom of page 4 at

http://www.alleghenyrodney.com/pages/products/PDF/302_305.pdf

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