Best Stainless Steel for Mirror like Surface.
Best Stainless Steel for Mirror like Surface.
(OP)
What stainless steel is best for mirror like finish/polish?
I am considering 321 316 or 321. Are they all about the same.. is does one polish better than the other?
FYI: this is to reduce the emissivity/radiation HT of the surface.
Thanks.
I am considering 321 316 or 321. Are they all about the same.. is does one polish better than the other?
FYI: this is to reduce the emissivity/radiation HT of the surface.
Thanks.





RE: Best Stainless Steel for Mirror like Surface.
Alloys with more chrome will hold that polish longer (not oxidize as rapidly). 309, 310...
RE: Best Stainless Steel for Mirror like Surface.
RE: Best Stainless Steel for Mirror like Surface.
"You see, wire telegraph is like a very long cat. You pull his tail in New York and his head is meowing in Los Angeles. Do you understand this? Radio operates the same way: You send signals here, they receive them there. The only difference is there is no cat." A. Einstein
RE: Best Stainless Steel for Mirror like Surface.
RE: Best Stainless Steel for Mirror like Surface.
Don't spend too much on a pretty finish. That only affects the specularity of the reflection, not the percentage of light reflected.
304 bright anneal will be very hard to improve upon. This can be purchased from service center stock. Anything more will be diminishing returns.
Michael McGuire
http://stainlesssteelforengineers.blogspot.com/
RE: Best Stainless Steel for Mirror like Surface.
CPro, there are published values for s.s. in most heat transfer textbooks that are much lower for "polished" than "mill" finish. Yes, specularity plays a role in lowering emissivity, but I think the ability to clean, and keep clean (i.e. free of heavy oxidation) is also part of it. It's easier to see the dullness of oxidation build-up on a previously polished surface.
RE: Best Stainless Steel for Mirror like Surface.
RE: Best Stainless Steel for Mirror like Surface.
RE: Best Stainless Steel for Mirror like Surface.
Michael McGuire
http://stainlesssteelforengineers.blogspot.com/
RE: Best Stainless Steel for Mirror like Surface.
In your vat repertoire of SS information do you have any information on the emissivity and reflectance of from a preoxidized surfaace on SS?
the reason for asking is that I was asked to do this on some 316 SS panels by using steam air + an organic for essentially the same purpose as the OP. I oxidized about 20 2'x 2' panels and shipped the off and never heard anything back.
RE: Best Stainless Steel for Mirror like Surface.
no worries, im going to calculate the emissivity based on wall temperature.
RE: Best Stainless Steel for Mirror like Surface.
A cold rolled sheet to high hardness will help.
The final surface will need to be electropolished to remove any smeared material.
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Plymouth Tube
RE: Best Stainless Steel for Mirror like Surface.
Mirror-like stainless have emissivity of 0.05 to 0.10 with reflectivity of 0.90 to 0.95.
Michael McGuire
http://stainlesssteelforengineers.blogspot.com/
RE: Best Stainless Steel for Mirror like Surface.
Thanks, they weren't doing what I thinking they were doing. Your information has got my curosity up. inquiring minds have got to know and the problem is that this group always worked behind closed doors and probably didn't leave any record.
RE: Best Stainless Steel for Mirror like Surface.
Michael McGuire
http://stainlesssteelforengineers.blogspot.com/
RE: Best Stainless Steel for Mirror like Surface.
TTFN
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RE: Best Stainless Steel for Mirror like Surface.
Michael McGuire
http://stainlesssteelforengineers.blogspot.com/
RE: Best Stainless Steel for Mirror like Surface.
TTFN
FAQ731-376: Eng-Tips.com Forum Policies
RE: Best Stainless Steel for Mirror like Surface.
Michael McGuire
http://stainlesssteelforengineers.blogspot.com/
RE: Best Stainless Steel for Mirror like Surface.
We used to gold plate a lot of heat shielding for s/c use, the issue was not oxidation build up in the vacuum environment of space, but the oxidation of the surface during the months leading up to launch. Radiant heating being the only heat transfer method available, surface finishes become critical to maintaining temperature environments for spacecraft. Gold being very noble, the oxide issue is avoided. Similarly, at higher temperatures (where gold may diffuse into substrates) rhodium or other platinum group "noble" metals were sometimes used.