Mild Steel Pipe vs. Ductile Iron Pipe

In pipeline engineering, mild steel pipe and ductile iron pipe are two common materials, which have significant differences in material composition, strength, corrosion resistance and service life. This article will compare the two in detail to help choose the most suitable pipeline material.

Material composition

Mild steel pipe is made of steel with a carbon content between 0.05% and 0.25%. It is a carbon steel pipe with high toughness and plasticity. Due to its low carbon content and excellent welding performance, it is suitable for engineering scenarios that require high-strength connections.

The material of ductile iron pipe is cast iron, which is formed by adding elements such as nickel and vanadium to form ductile iron, thereby improving the strength and toughness of the material. Its unique structure makes it have both the corrosion resistance of cast iron and the strength of steel.

Strength

The strength of mild steel pipe is higher than that of ductile iron pipe, mainly reflected in tensile strength and bending strength. Mild steel pipe is often used in engineering occasions with high pressure, such as transporting oil and natural gas, for OCTG pipe and casing pipe, etc.

Although the strength of ductile iron pipes is not as good as that of mild steel pipes, they have excellent pressure resistance and good impact resistance, making them suitable for municipal water supply, drainage systems, and low-pressure gas transportation.

Corrosion resistance

Mild steel pipes have poor corrosion resistance and are easily corroded and oxidized in humid or chemically corrosive environments. Therefore, when using mild steel pipes, additional anti-corrosion measures such as coating or galvanizing are usually required.

Ductile iron pipes have good corrosion resistance and can resist erosion by soil, moisture, and chemicals, making them particularly suitable for use in engineering occasions such as high-speed railway subgrades.

Service life

The service life of mild steel pipes is about 20 years. If the environment is highly corrosive and no effective anti-corrosion measures are taken, their service life may be greatly shortened.

The service life of ductile iron pipes can reach more than 40 years, and their long life makes them an ideal choice for municipal engineering and infrastructure construction.

Selection suggestions

In general, mild steel pipes and ductile iron pipes have their own advantages and disadvantages:

Mild steel pipes are suitable for high-pressure and high-mechanical-strength occasions, but have poor corrosion resistance.

Ductile iron pipes are suitable for low-pressure systems such as municipal water supply, drainage, and gas transmission, and are corrosion-resistant and have a long service life.

Summary

In summary, mild steel pipes and ductile iron pipes have their own advantages and disadvantages, and should be selected according to the needs of specific projects. In practical applications, it is necessary to fully consider factors such as material strength, corrosion resistance, and service life, and to carry out reasonable design and use.