The passivation of stainless steel is a surface chemical treatment aimed at improving corrosion resistance and restoring the natural protection of the material.
Stainless steel, in fact, protects itself spontaneously thanks to a thin and invisible layer of chromium oxide (Cr₂O₃), which forms when it comes into contact with oxygen in the air. However, during mechanical or thermal processing, the surface of the steel can become contaminated with particles of free iron or other elements, which compromise the effectiveness of the passive layer and increase the risk of corrosion.
The passivation process consists of removing these contaminations and promoting the formation of a uniform protective layer, thus ensuring greater durability of stainless steel components.
• Chemical passivation treatment for stainless steel compliant with ASTM A967, ASTM A380 and ISO 16048 standards
• Removal of ferrous contaminations and restoration of the protective passive chromium oxide layer
• Improvement of corrosion resistance in aggressive and industrial environments
• No impact on the aesthetic appearance of the material (non-aggressive treatment on the surface)
• Process compatible with different grades of stainless steel (AISI 304, 316, 430, etc.)
• Minimum dimensions: a few millimeters
• Maximum cylinder dimensions: 950 mm – ø 450 mm – weight 450 kg
• Maximum parallelepiped dimensions: 950x450x850 mm – weight 450 kg
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Reference standards |
ASTM A967, ASTM A380, ASTM A480, ISO 16048 |
| Passive layer thickness |
Invisible protective layer, formed by Chromium Oxide, tipically less than 0,01 μm |
|
Visual Appearance |
No aesthetic alteration of the material; surface finish unchanged |
|
Corrosion Resistence |
Over 100 hrs in salt spray according to ISO 9227 |
|
Available final treatments |
By immersion or spraying, on stainless steel components (AISI 304, 316, 430, ecc.) |
• Food and Beverage Industry (for clean and hygienic surfaces, preventing food contamination and complying with health regulations)
• Pharmaceutical Sector (maximum surface purity and corrosion resistance in sterile environments and with frequent chemical washing)
• Chemical Industry (protection of tanks, pipelines and equipment in contact with aggressive and corrosive substances)
• Energy Sector (turbines, heat exchangers, and other applications where stainless steel is exposed to extreme temperature and pressure conditions)
• Automotive and Transportation (exhaust parts, tanks and other components subject to thermal shocks and atmospheric agents)
• Aerospace and Defense (essential for anti-corrosion protection, safety and reliability in extreme conditions)
No, passivation does not alter the aesthetic appearance of stainless steel. On the contrary, it can improve the surface finish, making it more uniform and brighter.
No, passivation does not modify the mechanical properties of the material. The treatment acts only on the surface, improving corrosion resistance but not affecting characteristics such as hardness, tensile strength, or ductility.
Yes, thorough rinsing with demineralized water is essential to remove acid residues and prevent subsequent corrosion phenomena.
Passivation is particularly effective on austenitic stainless steels (300 series, e.g., AISI 304, 316) and ferritic stainless steels (400 series). For martensitic steels (e.g., AISI 420) and duplex steels, a specific evaluation is required and dedicated processes may be necessary.
