Applications involving pure or deionised water (ion-hungry bipolar) place particular demands on the surface finish. Electropolishing is the method of choice for significantly reducing the dissolution of iron from 316L, 904L or Duplex 2205 materials, thereby effectively controlling the phenomenon of rouging.
In the case of contaminated components, the reddish-brown depostis are removed along with the micro-burrs, and the austenitic structure is restored. The surface acquires the densest possible chromium oxide skin and is enriched to the maximum extent.

Nowadays, virtually all reactors and vessels for pharmaceutical applications undergo electrolytic polishing as a final finish.

Recommended treatments: grinding to the desired surface roughness followed by electrolytic polishing.