The corrosion resistance of stainless steel and other metals depends entirely on the surface condition and the thickness of the passivation layer.

 

Passivation can alter the corrosion rate, making the steel more corrosion-resistant.

 

▲ Using SURFOX electrolytic polishing can simultaneously clean welds and passivate.

 

Due to the formation of a passivation chromium oxide layer on its surface, stainless steel can resist corrosion. The formation of this protective layer is called passivation. Wear or overheating (caused by welding) can damage this protective layer and expose the metal to corrosion.

 

Passivation occurs when chromium in stainless steel comes into contact with oxygen in the air. This chemical reaction forms a passivation chromium oxide layer, thus protecting the stainless steel surface. To form a thick and uniform oxide chromium passivation layer, the base material surface must be completely clean and free of any contaminants.

 

Mechanical wear, heat treatment, welding, salt, strong acids, and electrical contamination can damage the chromium oxide layer and lead to unnecessary oxidation. To fully restore the corrosion resistance of stainless steel and avoid any interference during the passivation process, heat discoloration and other surface contaminants must be removed.

▲ Passivation phenomenon on the surface of stainless steel.

 

(Further reading:Electrolytic polishing machine ~ High-efficiency SURFOX electrolytic polishing machine with NSF certified electrolyte! 1-2m per minute! Improve work efficiency!)

 

SURFOX is a safe, effective, and fast electrochemical cleaning system. The cleaning speed of welds with this system is 1-2 meters per minute. The SURFOX system combines the cleaning power of electricity with the passivation properties of the electrolyte cleaning solution.

 

Passivation begins immediately after the electrochemical cleaning process with SURFOX is completed. It typically takes 24 to 48 hours to complete and stabilize passivation.

 

Passivation Phenomenon Video Showcase

 

(Source article & video: https://www.walter.com/surfox/passivation)