Stainless - Magnetic vs. Non-magnetic

[brotherdoc]

Quick question about stainless. I got some 430 stainless plates, they're magnetic. Anybody have any idea on how much longer a 300 grade steel would last? Think I should take them back and have the shop order 300 grade non-magnetic?

[Bigtoyota]

If they're magnetic, that means they have more iron in them. That could potentially bleed out into the electrolyte. It just means you will have to change the solution a bit more often. If you didn't pay too much for it it may be worth a test run in a small generator to see what happens.

[Stratous]

Quick question about stainless. I got some 430 stainless plates, they're magnetic. Anybody have any idea on how much longer a 300 grade steel would last? Think I should take them back and have the shop order 300 grade non-magnetic?

Here is a chart for open air corrosion.

Stainless Steels - Atmospheric Corrosion Resistance
Atmospheric Corrosion Resistance of Stainless Steels
Alloy Finish % Stained Area % Rusted Pit Density (A-537)
201 CR 15 1 7
301 CR 20 3 8
302 CR 5 3 8
304 CR 3 0 8
304L 2B 15 3 9
316 CR 2 0 9
316L 2B 1 0 10
321 2B 10 5 8
347 2B 15 5 8
410 no. 2 100 80 1
430 CR 100 20 8


Reference: Baker, E.A. and Lee, T.S. "Long Term Atmospheric Corrosion Behaviour of Various Grades of Stainless Steels". ASTM Symposium on Degradation of materials in the Atmosphere. Philadelphia, PA. May 12-13, 1986

Looks like 304 is waaaaaaaay better than 430