Stainless Steel as reflector in electonics. 3

[Maxham1]

I'm designing a cover (100 mm dia, 25 mm tall) that will fit over some heated fiber optics that we want to keep at 65 C (-5 C ambient). I'm thinking of making it out of stainless steel (303?) because it has a low enough thermal conductivity and its emissivity is low enough. The electonics equipment is not in any chemically harsh environment, just telecommunications, where there may be some humidity.
Do I need to passivate the surface to keep it from dulling over time?

Thanks for any help.

 

[unclesyd]

303 SS will dull over time.
If the project will afford it, ideally I would use 316 SS polished and if possible passivated with HNO3. If just polished with a polish such as Semichrome it will last quite a long time and the surface can easily be renewed
The starting material should have a good finish.

You can get the polish locally or at the website below. It is also very good on aluminum

http://www.winterbrookefarm.com

If this is large project come back with size and quantities as there are some other avenues of approach to your problem

 

[scooter911]

How about electropolishing it. I passivate stainless to remove the carbon from the surface to prevent rusting. Not sure but I'd talk to a plating shop they should be able to help.

 

[Maxham1]

unclesyd and scooter911,

Thanks for you feedback and advice! I think I'll have the parts passivated or electropolished.