Electropolishing and passivation
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chemni usip
The company Chemni Usip s.r.o. was founded in 1996 and the main focus of its activity is surface treatment of metals. This focus is due to the many years of experience of the company owners in this area, and the first introduced surface treatment technology was chemical nickel plating.
- Electropolishing and passivation
Our modern, fully automated production line provides comprehensive, state-of-the-art surface treatment services for stainless steel components.
Our range of services includes pickling, electropolishing, and chemical passivation of stainless steel. Each process is designed to ensure maximum corrosion protection while enhancing the appearance of the finished products. Throughout every stage of production, we place the highest emphasis on quality, precision, and process reliability.
Pickling
Pickling removes oxides, scale, heat tint, surface inclusions, and other surface irregularities from castings, semi-finished products, welded assemblies, and heat-treated components, resulting in a clean and chemically active surface ready for further processing or service.
- Maximum component dimensions for pickling (L × W × H): 1850 × 800 × 900 mm, with a maximum weight of 500 kg.
- Complies with the requirements of ASTM A380.
Electropolishing
Electropolishing is an electrochemical process that removes a thin layer of material and surface inclusions from metal components to produce a smooth, bright finish. By reducing surface roughness, the process significantly improves corrosion resistance and enhances resistance to fatigue stress.
Following electropolishing, the surface becomes enriched with chromium- and nickel-rich alloy constituents in their most favorable state for subsequent passivation, further strengthening the material’s protective properties.
Electropolishing is the ideal solution for applications requiring a superior surface finish, excellent corrosion resistance, and long-term durability.
- Maximum component dimensions for electropolishing (L × W × H): 1870 × 770 × 1000 mm, with a maximum weight of 500 kg.
- Complies with the requirements of ASTM B912 and ISO 15730.
- The standard material removal during electropolishing is approximately 20 µm. However, the actual removal depends on the initial surface roughness and the material grade. For components with a very smooth initial surface, material removal may be as low as 5 µm or less. A precise and uniform material removal across the entire surface cannot be guaranteed.
Passivation
Passivation is a controlled chemical oxidation process applied to stainless steel surfaces to enhance their natural corrosion resistance by forming a stable, protective passive layer.
This treatment effectively removes free iron contamination from the surface and promotes the formation of a chromium-rich oxide layer, significantly improving the material’s resistance to corrosion in demanding environments.
- Complies with the requirements of ASTM A967, AMS 2700, and ISO 16048.
- Maximum component dimensions for passivation (L × W × H): 2000 × 800 × 1000 mm, with a maximum weight of 500 kg.
Requirements for the quality of parts before the surface treatment of anti-corrosion steels
