ss 304 magnetic

[lahane1443]

we have supplied a meter made of A182 F 304L & A358 TP 304L.Now overseas customer has sent a photograph where A 182 F304L material is attracted by magnet.
What r the possible reasons for this.

 

[israelkk]

Cold drawing of 301/302/304 makes it a little bit ferromagnetic. Only annealed 304 will be non-magnetic.

 

[enmax]

I would agree with israelkk - cold working austenitic stainless steel like 304L will cause it to become magnetic. Another possibility is that, although the material was certified as 304L, it might have been a ferritic grade of stainless that was supplied inadvertently.

http://uk.linkedin.com/pub/terry-roberts/28/a9a/a10

 

[blacksmith37]

I think you can get slight ferromag with annealed 304 when Ni is minimum (and high Cr). Another possiblity for slight mag is 316. And , magnet materials seem to get stronger ever year. If this is important , I think you need an objective measurement of the ferromag.

 

[EdStainless]

Yes to all of the above, you need a real measurement.
If this effects the function of your meter then it should be part of your spec.

There is a difference between a material being ferromagnetic, and being magnetized.
I would hope that in your meter you require all materials to be demagnetized.
I presume that you are using 304 because you expect it to be non-ferromagnetic.

In addition to cold work you can find poorly made 304 that has residual ferrite in it. This material will be magnetic. Sometimes this can be fixed with long time, high temp annealing.

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Plymouth Tube

 

[racookpe1978]

I've seen slight "magnetic" tendencies on stainless steels after they've been welded with stainless filler material.

 

[EdStainless]

The feromagntetism of welds is due to residual ferrite in them.

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