Introduction to rust-proof oil, which is indispensable for metal parts

What is rust-proof oil?

Rust often refers to the corrosion of ferrous metals caused by the electrochemical reaction of water and oxygen in air. Rust-proof oil primarily utilizes its rust inhibitors to form a protective film on the metal surface, isolating water and oxygen, thereby preventing rust.

Common Classifications of Rust-Preventive Oils for Mechanical Parts Processing

1. Thin-film Rust-Preventive Oil

This oil film is thin and requires minimal use. It forms a thin, rust-proof film on the workpiece surface, leaving no impact on the product's appearance. It is easy to clean and offers excellent rust-proofing performance. It is suitable for inter-process rust prevention and sealing of parts in the automotive, hardware, and electronics industries.

2. Displacement Rust-Preventive Oil

It has dehydrating properties and is suitable for parts that have not been completely dried after cleaning. It displaces moisture, making subsequent cleaning easier. It is commonly used for inter-process rust prevention and sealing of parts.

3. Hard-film Rust-Preventive Oil

It offers excellent rust-proofing performance in humid and salt-spray environments. It is generally suitable for harsh environments such as marine applications, ship hulls, chassis, and equipment, where high rust-proofing performance is required.

4. Water-Based Rust Inhibitor

This product is diluted with water and is a low-cost, widely used for rust prevention between production processes for ferrous metals, alloy steels, and non-ferrous metals. It offers a short rust prevention period.

About Rust Inhibitor Selection

1. Choose Based on Product Material

Different metal materials have different requirements for rust-inhibitor oils. For example, cast iron and copper have different requirements for rust resistance.

2. Choose Based on the Rust Prevention Period

For short-term rust prevention, use a rust-inhibitor with a lower viscosity and a thinner film. For longer-term rust prevention, use a rust-inhibitor with a higher viscosity and a thicker film.

3. Choose Based on Product Structure and Application Method

For example, smaller products can be treated with immersion treatment, while larger, more complex products can be treated with spraying or brushing. Regardless of the application method, ensure that an effective rust-inhibitor film is formed on all surfaces to avoid localized rust. (Also, care should be taken to avoid direct contact between workers' hands and the metal surface. Human sweat contains rust-causing substances such as chloride ions and lactic acid, which can easily leave fingerprint-like rust on the workpiece surface.) 4. Select based on subsequent processing and assembly requirements.

These include subsequent processing, storage environment, packaging conditions, and whether cleaning is required before assembly.

Rust-Preventive Oil Usage and Precautions

1. Immersion Method: Advantages include forming a uniform, rust-proof film on the surface, ensuring complete coverage of the product, and low cost. Disadvantages: Suitable only for small products, requiring low-viscosity rust-proof oil, and requiring a well-drained immersion tank.

2. Spray Method: Suitable for large and complex products. A high-efficiency sprayer must be used. This can result in incomplete rust-proofing, and requires a well-ventilated work environment.

3. Brush Method: This method is simple to use, but ensures that every part of the workpiece is coated, and the brush must be clean before use.

4. Flushing Method: Highly efficient, reusable, and cost-effective, but requires regular drainage and replacement of the product in the tank to prevent excess moisture and other contaminants from affecting the rust-proofing effect.

The above points are some basic knowledge about the selection and use of anti-rust oil. In the production process, rust is still likely to occur even after using anti-rust oil. Common reasons include: too much moisture on the surface of the workpiece, the anti-rust film has not been formed on all the workpieces, the anti-rust oil has been used for a long time without being replaced, a large amount of moisture and dust remain in the oil, the anti-rust film on the surface of the workpiece is not fully formed before packaging, the temperature difference in the packaging causes water vapor condensation, the rust is more serious, the packaging material or quality does not meet the process requirements, etc.