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Mirror finish polish of stainless steel

February 25, 2011

Hi

I'm looking for a technique of high level of surface finish of stainless steel (321) tubes (external polish only).

I'm familiar with the electropolish process, but our tubes are around 100 mm in diameter and 4 m long and its involved non-environmental friendly acids etc.
are any other polish methods that we can reach Ra<0.1 uµm with shiny mirror finish ? it is important to note that I cannot accept any trace of grease or oil left on the tubes as well as any other for given material.

I have LOESER 10 stages abrasive machine and would like to use it wisely to polish stainless steel (321) tube of OD 70 mm.
the incoming tubes are typical annealed finished with Ra of around 1-2 um.
My goal eventually is to get Ra below 0.1 µm and as much as specular surface finish.

I'll appreciate help of abrasive grit size sequence and speed / force I need to apply for that purpose.

Also the durability of the abrasive belts its important of course

Thanks in advance.
Best Regards

Doron

Doron Nakar
Eng - Israel

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Doron,

Why don't you build plastic or even wood narrow tank of 4 m long. If the tank is from wood, put two layers of thick polyethylene inside. Put copper foil cathode inside. Pore in the heated electrolyte. it does not need to be very hazardous - the electrolyte based on phosphoric acid with special additives is not smelly, mild for the environment and easy to dispose after the polishing is done. It will take you only few minutes to polish the outer surface of such tubes. More you polish, better will be the finished surface.

Anna Berkovich
Russamer Lab

Pittsburgh, Pennsylvania

March 1, 2011