316 Ss

Discussion in 'Materials' started by eyschulman, Feb 20, 2014.

  1. michael pierzga
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    michael pierzga Senior Member

    If you want stainless to stay bright it must have no pits, scratches...it must be polished perfectly smooth. This is why high quality stainless work is so expensive.. Surface preparation and .polishing skill.
     
  2. Shipwrighttech
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    Shipwrighttech New Member

    316 stainless will NOT be magnetic. Lots of stainless steel is sold as 316, but the nickel, chrome, and molybendum mix actually used is a much lower-cost substitute for what should be utilized to give 316 it's higher resistance to rust.
    302/304 and some Duplex will be magnetic.
    Sourcing of the mill is almost as important nowadays as typing stainless.
    Mill certs are valuable tools and should be provided with little hassle from a quality supplier.
     
  3. jehardiman
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    jehardiman Senior Member

    And you can ruin it all if you don't keep your stainless polishing gear seperate from you steel polishing gear.

    If that is 316 here are a couple of thoughts...
    1) Given the pattern, was anything lying accross it? Basic 316 will pit in a wet environment if you restrict its access to oxygen, like covering it up or between flaying surfaces. Only 316 ELI won't pit in those conditions.
    2) Was it polished by somebody using steel contaminated gear. Something a simple as taking a steel wire brush it the surface will imbed free iron in the surface which will start pitting.
    3) Also a typical problem is the use of HSTS to machine SS or reusing cooling fluid in NC machines. This will also imbed free iron in the surface that will lead to problems.
     

  4. baeckmo
    Joined: Jun 2009
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    baeckmo Hydrodynamics

    Re magnetic SS: There are cast qualities of SS316 (basically austenitic) that are slightly magnetic due to remains of martensitic/ferritic chrystalline structures.

    If you have a piece of soft steel available, you easily feel the difference in attachment force between soft steel, cast 316, rolled 316 and a martensitic SS quality (often found in shafts).
     
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