4 Anti-rust Methods for Seamless Carbon Steel Pipes

The main anti-rust treatment methods for seamless carbon steel pipes are as follows:

Surface treatment method

1. Mechanical cleaning

Use mechanical means such as grinding and polishing to remove impurities such as rust and scale on the surface of the seamless carbon steel pipe to make the surface of the steel pipe smooth. Then carry out subsequent treatments such as spraying anti-rust paint to effectively improve the anti-rust effect.

For example, use a grinding wheel to grind the surface of the seamless carbon steel pipe to remove the rough and uneven parts. When grinding, pay attention to uniform strength to avoid excessive grinding and damage to the steel pipe.

2. Chemical cleaning

Use chemical agents to clean the seamless carbon steel pipe to remove oil and rust on the surface. Commonly used chemical cleaning agents include pickling agents, alkaline cleaning agents, etc. Pickling agents can dissolve oxides such as pipe rust, while alkaline cleaning agents can remove oil stains. After cleaning, rinse thoroughly with clean water and dry.

For example, hydrochloric acid is used to clean the rust on the surface of the steel pipe. The hydrochloric acid reacts with the rust to form water-soluble ferric chloride. After cleaning, rinse with clean water until neutral, and then carry out anti-rust treatment.

Coating protection method

1. Paint coating

Applying anti-rust paint on the surface of seamless carbon steel pipe is a common anti-rust method. Anti-rust paint has good anti-rust performance and adhesion, and can form a protective film on the surface of the steel pipe to prevent oxygen and moisture from contacting the seamless carbon steel pipe.

Generally, the primer can be applied first, and then the topcoat can be applied after the primer is dry to increase the thickness and durability of the coating. Different types of anti-rust paints can be selected for different use environments and requirements, such as oil-based anti-rust paint, epoxy anti-rust paint, polyurethane anti-rust paint, etc.

2. Galvanized coating

Galvanizing is a more effective anti-rust method. By plating a layer of zinc on the surface of the steel pipe to form a zinc-iron alloy layer, it can effectively prevent oxygen and moisture from corroding the steel pipe.

Galvanizing is divided into two methods: hot-dip galvanizing and electrogalvanizing. Hot-dip galvanizing has the advantages of thick coating and good corrosion resistance, but the cost is high; electrogalvanizing has low cost and simple operation, but the coating is relatively thin and the corrosion resistance is slightly poor.

Use of rust inhibitors

1. Volatile rust inhibitors

This type of rust inhibitor can volatilize at room temperature and form a dense monomolecular film on the surface of the seamless carbon steel pipe, thereby playing an anti-rust role. It has the advantages of being easy to use and not affecting the processing and use of steel pipes, but the anti-rust period is relatively short, and it is generally suitable for short-term or temporary rust prevention.

For example, apply volatile rust inhibitors on the surface of CS seamless pipes, or soak the steel pipes in rust inhibitor solutions to adsorb rust inhibitor molecules on their surfaces.

2. Sealed rust inhibitors

Sealed rust inhibitors are mainly used for long-term pipe rust prevention. They can form a stable anti-rust film on the surface of seamless carbon steel pipes, and have good permeability, which can penetrate into the interior of steel pipes to play an anti-rust role. There are many ways to use sealed rust inhibitors, such as brushing, soaking, and spraying.

You can choose the appropriate method according to the actual situation. For example, for large seamless carbon steel pipes, the method of soaking and sealing the rust inhibitor can be used to completely immerse the steel pipe in the rust inhibitor solution to ensure that the surface of the seamless carbon steel pipe is fully in contact with the rust inhibitor.

Change environmental conditions

1. Control humidity

Humidity is one of the important factors affecting the anti-rust effect of seamless carbon steel pipes. When the relative humidity is below 60%, the steel is not easy to rust. Therefore, the steel pipe should be stored in a dry and ventilated environment as much as possible, and avoid storage in a humid environment. If it is impossible to avoid using or storing the steel pipe in a humid environment, a dehumidification device can be used to reduce the ambient humidity.

2. Isolate from air

Isolating from air can prevent oxygen from contacting the seamless carbon steel pipe, thereby slowing down the rusting rate. The steel pipe can be sealed in a plastic bag, paper bag or metal container by sealed packaging to avoid contact with air. For steel pipes stored for a long time, inert gas, such as nitrogen, can also be filled to further improve the anti-rust effect.

Summary

In short, the selection of a suitable anti-rust treatment method should be based on the use environment, requirements and cost of seamless carbon steel pipes. In practical applications, a combination of multiple anti-rust treatment methods can be used according to specific circumstances to achieve better anti-rust effects.