This is my first post to this forum and hence please bear with me if I have broken some rules

I am from India and we manufacture some components from bearing steel. After machining they are heat treated and as a result their hardness is around HRC 62-65.

Later the components are polished in Vibratory & Centrifugal Polishing Machines. Abrasive ceramic media (Grey) is used for deburring and polishing while for very silky finish we use non abrasive type ceramic media (white).

Initially we put the components in vibratory machine filled with abrasive ceramic media and mild solution of oxalic acid to clean the oil and salts of heat treatment. After 30 mins we wash out oxalic acid and then mild solution of caustic soda is added and the machine runs for another 90 mins. Then we again wash out the solution and add another shot of caustic soda and run the machine for 90 mins.

After this the components are put into centrifugal polishing machine where we use non abrasive type media and a mildly thick greenish liquid to get very silky finish. The machine is run for about 1 hour.

Now the problem:

Though the finish we receive is pretty good and acceptable the luster is dull and hence we need to manually buff the rings as hard chrome coating is the next process. I have noted that many companies in India as well as world over produce same components with better finish without buffing their components.

Where do I need to make alterations?

Please help.

Thanks for reading the long post.

Prasham