How To Prevent Corrosion on The Inner Wall of Mild Steel Pipe?

As a carbon steel pipe, mild steel pipes are widely used as pipes in the fields of petroleum, chemical industry, pharmaceuticals, ships, etc. However, due to long-term use and the influence of environmental factors, the inner wall is prone to corrosion and stains, which affects the normal transportation and service life of the pipeline. Therefore, it is very necessary to carry out anti-corrosion treatment of the inner wall of mild steel pipes.

Methods for anti-corrosion of the inner wall of mild steel pipes

1. Coating method

Coating method is a common method for anti-corrosion of the inner wall of mild steel pipes. The coating can be divided into three types: inorganic coating, organic coating and special coating, each with its own advantages and disadvantages.

Inorganic coating:

The advantage is that it has strong high temperature resistance and corrosion resistance, long service life, but the cost is high.

Organic coating:

The advantage is simple production, low cost, and certain corrosion resistance, but the service life is short.

Special coating:

Including polyurethane coating, epoxy amino ester coating and other types, with good chemical corrosion resistance, friction resistance, high temperature resistance, impact resistance, etc., but the price is high.

2. Sealing method

The sealing method is to seal the inside of the mild steel pipe and fix it with stainless steel pipes or plastic pipes to achieve the anti-corrosion effect. This method does not require chemical treatment during the construction phase, so it is suitable for some pipes that are difficult to chemically treat. But the cost is high and it is not suitable for large-diameter pipes.

3. Cathodic protection method

The cathodic protection method is a method of protecting the pipe by applying current to oxidize the anode. This method is simple to use and suitable for underground buried pipes, but requires professional personnel to monitor and maintain the cathodic protection system.

4. Lining method

The lining method is to chemically treat the sealed inner wall, or line the inside with a layer of material with good corrosion resistance, such as rubber, ceramic, etc. The advantages of this method are wide application and low cost, but it requires a relatively closed pipe interior.

Anti-corrosion treatment technology for the inner wall of mild steel pipes

1. Chemical treatment technology

Surface corrosive agent treatment:

By using acidic or alkaline corrosive agents, oxides and other impurities on the inner wall of the steel pipe can be effectively removed, laying the foundation for subsequent rust prevention work. However, it should be noted that this treatment may reduce the surface roughness of the pipe wall and have a certain impact on its mechanical properties.

Pickling treatment:

Using strong acid for cleaning can not only remove rust and dirt, but also significantly improve the rust resistance of the inner wall. However, this method may also have a certain impact on the corrosion resistance of the pipe wall.

2. Mechanical treatment technology

High temperature welding treatment:

Through high temperature welding, the inner wall of the steel pipe is formed with oxide scale, which reduces the risk of internal metal oxidation and thus extends the service life of the steel pipe.

Inner wall grinding treatment:

Grinding technology can improve the smoothness and roughness of the pipe wall surface, thereby enhancing its corrosion resistance. However, this operation process is relatively complicated and may affect the fatigue performance of the metal.

3. Electrochemical treatment technology

Anodic electrochemical treatment:

In the electrochemical solution, the inner wall of the steel pipe is used as the anode, and the oxide is reduced to metal through electrolysis reaction to form a protective layer to improve the anti-corrosion performance.

Anodic protection technology:

Anodic protection technology uses an external power source or protection circuit to treat the inner wall of the steel pipe to form a protective film to enhance its corrosion resistance without negatively affecting the mechanical properties.