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Ted Mooney, P.E. RET
Pine Beach, NJ
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for Metal Finishing since 1989
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Does magnetizing stainless steel decrease its corrosion resistance?
Q. If I magnetize the AISI 420, there is a possibility to decrease its corrosion resistance?
Edson RodriguesIndustrial Mechanical Engineer - Camacari, Bahia, Brazil
March 29, 2016
A. Hi Edson. I doubt it, and I've never heard of the magnetizing or degaussing of steel or stainless steel affecting its corrosion resistance, but I don't actually know. So I hope your posting draws some responses :-)
Regards,
Ted Mooney, P.E. RET
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
March 2016
March 29, 2016
A. I think I'll just quote this article directly:
http://www.bssa.org.uk/topics.php?article=76
Softening is done by heating in the 1050-1120 °C range, ideally followed by rapid cooling.
This is of course the complete opposite to martensitic steels, where this sort of treatment would harden the steel.
Cold worked austenitic stainless steels will contain some 'strain induced' martensite, which, as well as making the steel partially 'ferro-magnetic', can also reduce the corrosion resistance.
A highly stressed cold worked structure may also have lower general corrosion resistance than a fully softened austenitic structure."
With a austenitic (300 series) stainless steel, if it has become magnetic then it is generally heat treated (called annealing in this case) to undo the effects of the cold working that caused it. 420, being a martensitic grade, I believe is always magnetic.
Ray Kremer
Stellar Solutions, Inc.
McHenry, Illinois
Q. I would like to thank for the responses from everybody.
In order to clarify my question, I am referring to putting an AISI 420 stainless steel together with a magnet. After separating the steel from the magnet, there remains a residual amount of magnetization in the steel. In this situation, can the AISI 420 decrease its corrosion resistance?
EF Engenharia - Camacari, Bahia, Brazil
March 29, 2016
A. Hi again. As before, I suspect no effect, but don't know for sure. But degaussing is a very simple standard procedure employed on even very cheap steel articles like hardware.
Regards,
Ted Mooney, P.E. RET
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
March 2016
March 31, 2016
A. Hi Edson
Your magnetic stainless may attract any stray iron particles onto the surface and could create potential corrosion sites
Geoff Smith
Hampshire, England
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March 31, 2016
EF Engenharia - Camacari, Bahia, Brazil April 7, 2016 A. I was going to jump in here and say "No, being magnetically charged doesn't affect the corrosion resistance at all". And then Geoff noted something I'd completely missed! Good point!  Lee Gearhart metallurgist - E. Aurora, New York |
Hi Lee,
Very good response. Now, I think that my inquiry was totaly respnded.
Thank to Lee and to everybody.
EF Engenharia - Camacari, Bahia, Brazil
April 9, 2016
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