Phosphating of parts: improving performance characteristics

Phosphating is a process of forming a phosphate film on the metal surface that significantly improves its performance characteristics. KARBAZ offers phosphating services using advanced technologies and equipment, which ensures high-quality treatment and a long service life of parts.

Technical Capabilities for Phosphating

We are able to treat a wide range of parts, including:

• Rings, gear wheels, drill pipe tool joints, flanges, etc.: Up to 500 mm in diameter.
• Shafts, extensions, studs, etc.: Up to 600 mm in length.
• Weight of treated parts: Up to 100 kg.

Purpose of Phosphating

Phosphating the surfaces of metal products serves several purposes:

• Anti-friction properties: Reducing friction between parts.
• Electrical insulating properties: Improving insulating characteristics.
• Anti-seize properties: Increasing resistance to galling.
• Paint adhesion: Improving the adhesion of paint to the surface.
• Anti-corrosion properties: Increasing corrosion resistance.

The Phosphating Process

Phosphating is carried out in a solution of primary metal phosphate salts (iron, manganese or zinc) in water at a temperature of 86–98 °C. The process takes 40 to 80 minutes, depending on the type of metal being treated.

There are two main phosphating methods:

1. Hot phosphating: Used to create protective coatings on mechanical engineering parts.
2. Cold phosphating: Used for treating parts by spraying or in cases where heating is undesirable. The coatings obtained by this method are amorphous and are only suitable as a primer for painting.

To obtain a high-quality phosphate coating, the parts must be thoroughly cleaned and degreased. With proper cleaning, a dense layer 5–10 µm thick forms on the surface of the parts.

Main Stages of Manufacturing Parts Subject to Phosphating

1. Rough machining: Preliminary preparation of the parts.
2. Preliminary heat treatment: Includes hardening and tempering to ensure high toughness and strength of the part core. Hardening is carried out at 850–950 °C followed by cooling; tempering is carried out at a temperature that depends on the requirements for the parts.
3. Finish machining: Grinding and giving the parts the required geometric parameters.
4. Surface preparation: Degreasing and cleaning to ensure a fine-grained coating. Sandblasting or glass bead blasting may be used.
5. Protection of surface areas: Areas not to be phosphated are protected with liquid glass or a tin coating.
6. Phosphating proper: Applying the phosphate layer to the surface of the parts.

Advantages of Phosphating

Phosphating metal surfaces provides a number of significant advantages:

• Improved adhesion of paint and coatings: The phosphate layer improves the adhesion of subsequent coatings, ensuring durability and an attractive appearance.
• Corrosion protection: The phosphate film prevents corrosion and wear of the metal, especially in conditions of high humidity or aggressive environments.
• Base coat: Serves as a base for further treatment, such as the application of paint or powder coatings.

Applications of Phosphating

Phosphating is widely used in various industries, such as:

• Automotive industry: To protect metal parts from corrosion and improve their appearance.
• Mechanical engineering: To increase the wear resistance and durability of components.
• Electronics industry: To improve the electrical insulating properties of parts.

KARBAZ offers high-quality phosphating services for metal parts. Our advanced technologies and experienced staff ensure high processing standards, meeting the needs of customers in various industries. Contact us for advice and to place an order for phosphating services — we guarantee reliability, quality and prompt execution of your orders.