Passivation of Stainless Steel

In terms of aesthetics and corrosion resistance, stainless steel has all the right characteristics to make for beautiful wire mesh. However, stainless steel looks and performs its best when it is clean. The chromium content in stainless steel combines with oxygen in the air to create a natural passive chromium oxide layer. This chromium oxide layer protects the material from further corrosion. Contaminants of various kinds inhibit this passive oxide layer from developing to its fullest ability leaving the material susceptible to attack. A nitric or citric acid process (passivation) enhances the formation of this oxide layer allowing the stainless steel surfaces to be in an optimal “passive” state.

Rust on stainless: Rust developing on stainless steel is usually due to surface contamination of iron deposits embedded in the surface. Mechanical abrasions on stainless steel from non stainless tools is one common way iron contaminates exist on stainless steel. Once moisture is present, the iron embedded in the stainless steel will begin to rust.  Steel bands used in directly strapping down the product to a skid is also a common means of contaminating the stainless steel. Before final install and after all processing of the material is complete a passivation process (such as nitric or citric acid) should be performed to remove any potential free iron that would otherwise corrode. Citric and nitric acid do not alter the appearance of stainless steel.

Appropriate wire mesh base alloys:

Stainless Steel

Corrosion resistance: Passivation using Nitric or Citric acid removes contaminates and builds the corrosion resistance ability of stainless to its fullest potential.

Wire mesh and frame assemblies: The passivation process should be performed only after all fabrication and assembly is complete.