Why Carbon Pipes Are Rusty

Are you always confused why carbon pipes are rusty in a relatively short time and how to solve this little annoyed problem? Let me unravel the mystery.

Carbon steel pipe is a kind of steel with high carbon content, and it is prone to oxidation reaction in humid environment, forming iron oxide, that is rusting because its main component contains iron element. Although carbon steel is not a completely corrosion-resistant material, it is susceptible to environmental corrosion, which aggravates the occurrence of rust because its surface has not been specially treated. 

There are four reasons for rusting of carbon steel pipes as follows:

1. Medium that causes product corrosion

Moist air, hand sweat or dirt from product contact, water acid, alkali, salt and chemical gases remaining on the metal surface may cause metal corrosion.

2. corrosion resistance of metal

Metals that are prone to rust include pig iron, carbon steel and structural alloy steel. Meanwhile, stainless steel, high-temperature alloys and titanium alloys will rust in special environments. 

3. Parts prone to rust

The parts that are easy to contact, adhere to and accumulate corrosive substances include grooves, seams, holes, edges, joint surfaces, hand contact surfaces, parking surfaces, rough surfaces, newly processed surfaces, or sandblasting polished surfaces etc, which are prone to rust. 

4. Corrosion-prone environment

Generally speaking, processing workshops such as pickling, heat treatment, electroplating, welding, painting, electrolysis etc are more prone to corrosion than mechanical processing workshops, because these workshops have a large amount of corrosive media.

However, there are indeed effective and strong rust prevention methods for carbon steel pipes as follows: 

1. Passivation

Rust is prevented by passivation. Passivation treatment is to form a protective oxide layer on the surface of carbon steel, which can prevent the steel from being further corroded by the environment.

2. Surface coating

Surface coatings such as galvanizing and painting can effectively prevent carbon steel from rusting and form a protective film on the surface, which can resist corrosion from the external environment and improve the hardness and durability of the surface.

3. Cement coating

Cement coating is another method for carbon steel to prevent rust. Although cement will absorb water, it will directly form a protective layer on the surface of the steel pipe. Therefore, cement coating is also a method of rust prevention. 

4. Anti-rust oil treatment

The anti-rust oil added with anti-rust agent can prevent the rust of carbon steel, and well can be used as anti-rust treatment for engineering machinery, automobile engine parts and so on. The use of high-density grease and preservatives can prevent oxygen from entering the surface of carbon steel, thereby reducing the occurrence of oxidation reactions. 

5. Electronic rust removal technology

The application of electronic rust removal technology can completely remove the rusty substances generated on the surface of carbon steel without changing the physical properties of the steel, so as to achieve the purpose of rust prevention.

In a word, Tianjin Tewoo (acero.sigridsun@gmail.com) can be your reliable partner to provide products with best quality and related technical knowledge and service.