Best Stainless Steel for Mirror like Surface.

[zj4041]

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.

 

[btrueblood]

Thought I said that?

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.