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Old December 22nd 08, 10:12 PM posted to rec.photo.digital,rec.photo.digital.point+shoot,rec.photo.digital.slr-systems
ASAAR
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Default Digital Photo Frames for refrigirators??

On Mon, 22 Dec 2008 14:24:15 -0600, "mcdonaldREMOVE TO ACTUALLY
REACH wrote:

Some grades of stainless steel aren't magnetic. Depends on how much
nickel is in it, I gather.


No, how much chromium. Low chromium makes it magnetic.


No, back atcha! Unlike humans, steel that's got the hots is
non-magnetic. Nickel makes the non-magnetic state stable at low
temperatures. This is shown in the quote below. If chromium also
has this property, it's probably less effective than nickel. The
same web page notes that to increase the corrosion resistance of
steel, chromium is added.

At room temperature Mild Steel is magnetic - the atoms are arranged
to form a structure that is predominantly ferrite. Ferrite is magnetic.
Once steel is heated to above 730°C the atoms will tend to rearrange
into a phase called Austenite. Austenite is non-magnetic. So very hot
steel is not magnetic….who cares!

An interesting fact is that some alloy additions will encourage Austenite
to be stable at room temperature, the result being a steel which is
non-magnetic at room temperature. One such alloy is Nickel. The 300
series of stainless steels contain sufficient Nickel to render them
non-magnetic. As 316/L & 304/L are the most common stainless steel
grades used, they are the grades that most people are familiar with.
All of the stainless steels from the 300 series are non-magnetic. This has
resulted in the misconception that all stainless steels are non-magnetic.
But the fact remains that stainless steels from the other series such as
200, 400, PH, duplex etc have higher percentages of ferrite and are
therefore magnetic. Some of these “magnetic” stainless steels have
superior strength and corrosion resistance than those of the 300 series.


http://www.supremesteel.co.nz/articl...l_magnetic.php