Electro PolishBasically, electro polishing is electro-plating in reverse. But instead of depositing a coating of another material on a surface, the action of electro polishing removes a surface layer, typically 20-40 microns in depth in the case of stainless steel. This removal of an often contaminated surface layer and the electrochemical action of micro-smoothing results in electro polished stainless steel surfaces being bright and highly reflective and the advantages are many.
The corrosion resistance of stainless steel may also be improved by passivating the surface.
All stainless steels are iron-based alloys (minimum 50% iron) and have at least 10.5% chromium. The chromium content is the key to stainless steel's basic corrosion resistance. When the chromium is exposed to oxygen, it spontaneously forms a passive oxide layer. This passive oxide layer is very thin, yet it prevents further diffusion of oxygen into the base material and thus prevents corrosion.