Sunday, July 27, 2008

Removing magnetism from Austenitic Stainless steel

I bought some 304 stainless steel tubing for building a fuel cell and found that even though it was touted as being austenitic, it had a magnetic field down the welded seam (nowhere else). I had tested the tubes with a neodymium magnet and saw where the field was. Will your degausser remove the magnetic field?

The degausser will not prevent the austenitic stainless from being magnetic. It will remove magnetic fields excepting the earth's magnetic field.

Austenitic is slightly magnetic when cold worked. In the fully annealed condition it is non-magnetic.

Any austenitic (300 series) stainless steel which is magnetic can be returned to non-magnetic condition by stress relieving to 700-800 degrees C. It then reverts back to its fully annealed condition and is softer and weaker. There may be other issues with annealing so the best thing to do would be to engage a metallurgist.

The degausser will remove an artificial magnetic field from a iron object, leaving just the earth's magnetic field. By testing with a magnet you have probably slightly magnetiized the weld area (stressed area).

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