WHY TO PICKLE & PASSIVATE
ON STAINLESS STEEL
Pickling passivation ensures corrosion resistance to components of stainless steel and thus considerably increases their life and usefulness.
The corrosion resistance of stainless steel is due to the presence of at least thirteen percent chromium in the alloy. With oxygen, the chromium forms a dense chemically resistant passive layer of chromic oxide, protecting the surface of the component against corrosion. The passive layer usually forms again after abrasion. The precondition to corrosion resistance and
Every mechanical treatment damages the top layer of components i.e.
- Contamination with Ferric matter
- Change in the structure of the layers
- Development of inbuilt stress
- Reduction of chromium content
Heat treatment like annealing and welding leads to scaling and
Corrosive strain on insufficiently Passivated stainless steel leads to :
- Pitting corrosion
- Crevice corrosion
- Stress corrosion cracking
- Corrosion resulting from contact with foreign metals.
A dense passive layer can only form on metallically pure surfaces. Professionally pickled Passivated stainless steel surface and welding seams:
- Are metallically pure, free of scales and
- Give the full corrosion resistance of the component
- Have a decorative metallic appearance.
K-2 products of surface innovators are approved by Indian Institute of Technology (IIT) under ASTM-A 380 and ASTM A-967 for pickling & passivation on stainless steel.