Date:         Wed, 30 Dec 1998 22:15:10 -0500
Reply-To:     Martin Jagersand <jag@CS.YALE.EDU>
Sender:       Vanagon Mailing List <vanagon@vanagon.com>
From:         Martin Jagersand <jag@CS.YALE.EDU>
Subject:      Re: How to tell if it is stainless steel pipe? (careful,I'm
              technobabbling)
Comments: To: PaoloD1455@AOL.COM

Thanks Paul for the knowledgeable comments.

> From:    Paolo Damiani <PaoloD1455@AOL.COM>
>
> If it's at all magnetic, it's not a 300 series stainless. 300 series SSs are
> austenitic and therefore non-magnetic. Ferritic or duplex SSs are magnetic.
> Generally speaking the austenitic steels (300 series) have superior corrosion
> resistance to the others.
> I have seen welded 300 series SSs show some mild magnetic properties, but this
> is usually due to no or poor heat treating after the welding. These areas tend
> to be more susceptible to corrosion because of this loss of austenite and
> formation of HAZ.

So intuitively could you say that ferritic or austenitic depends on
wether the magnetic domains are randomly or coherently oriented, and
that orientation can be disturbed either by adding more chromium etc.
to the alloy or by heat treating. However I'm puzzled since it seems to
me that a rapid cooling like after welding will cause random orientations
and hence be non-magnetic, not like you say mildly magnetic.

> There are "acid test" kits out there to determine alloys.  I'm not sure if
> it's worth the trouble.  Alternatively, if you have a friend at a university
> or in industry with access to analytical equipment, you might get be able to
> get a "freebie".

Is there some way to compose a test kit from household chemicals?
John suggested vineger. What types of steel would that leave intact
and what ones corrode?

> has a scanning electron microscope with ED Spectrometer capability (pretty
> common instrument) and have them run an EDS analysis.
>
> Make sure they run it at least 30 kV.  You should a fairly good "semi-

I love these high-tech superexpensive solutions to solve my own
private problems! However no freebee's for me here I'm afraid.

Thanks,
MArtin
--
Westy 1.9l Turbo Diesel
Quantum 1.6l Turbo Diesel

Martin Jagersand                 email: jag@cs.yale.edu
Computer Science Department             jag@cs.rochester.edu
Yale University

        Slow down and visit the VW diesel Westy page:
          WWW: http://www.cs.rochester.edu/u/jag/vw
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