Re: [Harp-L] This Stainless Steel thread



OK, here's the deal on stainless steel and magnetism. Steel has several different possible crystal structures. The austenitic structure in chrome stainless steel like that used in cookware, sinks, and a lot of other applications is non-magnetic. However, if this variety of stainless is heated to temperatures above a critical point that varies a bit with alloy composition and not cooled rapidly to room temperature, the crystal structure will be a mixture of (mostly) austenite and ferrite. Ferrite is magnetic. Thus the area around welds is sometimes magnetic. The ferritic structure is much more prone to corrosion, thus the rust you sometimes see near welds in stainless steel.



On 6/10/2012 5:08 AM, Aongus MacCana wrote:
There are various grades of stainless steel depending on the alloying
components. Here in Ireland the plumbers' rule of thumb on the quality of
stainless steel kitchen sinks used to be whether they would attract a magnet
or not. If they were not magnetic "they were the right stuff". If a magnet
was attracted to them they might be inferior and subject to slight rusting.

I made the interesting discovery that some of the new Euro coinage, must
have a ferrous component. I had a keyring attachment for holding a metal
token which could substitute for a Euro coin when releasing a supermarket
trolley. I lost the token, but lo and behold if the magnet of the token
holder in my pocket did not attach itself to a real Euro. By the way I do
not plan to put a magnet near the stainless reeds of my trusty Seydel 1847
anytime soon.

Beannachtai

Aongus Mac Cana






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