Carbon Steel vs Black Steel

Carbon steel is made from carbon and iron, giving it strength and durability. It is commonly used in various industries such as oil and gas, construction, and water treatment due to its high tensile strength and resistance to corrosion. The carbon content in the steel determines its quality, with higher levels producing stronger pipes suitable for high-pressure applications. Carbon steel are also known for their affordability compared to other materials like stainless steel or copper.

Black steel are a type of steel that have been subjected to a blackening process, giving them their characteristic dark appearance. These pipes are also known as black iron pipes or black malleable iron pipes. Unlike other steel pipes that have a shiny, silver-grey surface, black steel pipes have a dark and matte finish, which sets them apart in terms of aesthetics and applications. 

Difference Between Carbon Steel and Black Steel?

Chemical composition:

Both carbon steel and black steel are primarily made of iron and carbon. That's why they are very powerful. Although the two alloys have different percentages of carbon content, their composition is the same.

Carbon steel‌ is an iron-carbon alloy with a carbon content between 0.0218% and 2.11%. It is sometimes called carbon steel. In addition to carbon, it also contains small amounts of silicon, manganese, sulfur, phosphorus and other elements. According to the carbon content, carbon steel can be divided into low carbon steel (carbon content ≤0.25%), medium carbon steel (carbon content 0.25% to 0.6%) and high carbon steel (carbon content >0.6%). The hardness and strength of carbon steel increase as the carbon content increases, but the plasticity decreases. Carbon steel is widely used in many fields because of its low cost and good workability.

Black steel refers to ordinary carbon steel materials that are not galvanized or coated. The main components are iron and carbon. They appear black because the surface has not been treated. Black steel is an alloy steel with carbon as the main component, containing 0.3% to 1.7% carbon. It is suitable for making parts that require strength and corrosion resistance.

Production process:
In terms of production technology, carbon steel needs to add appropriate elements, undergo a series of processes such as quenching and annealing to make the ideal product. The production of black steel is relatively simple and can be directly made by cold rolling or hot rolling.

Corrosion resistance:
Carbon steel is very susceptible to corrosive agents, including chlorine, bleach, strong acids, and even high-humidity air. This is because these corrosive agents or moist air react with the carbon atoms within the carbon steel.

Black steel is resistant to corrosion and wear due to the high magnetite content on its surface. This is why black steel is often used in applications such as pipes that may require contact with corrosive agents.

Strength:
Both steels are very high in terms of structural strength and have similar characteristics in terms of weldability, ductility and ductility. However, black steel has better welding capabilities.

Application areas:

Since carbon steel‌ and black steel are similar in hardness, strength, and longevity, they are primarily used in similar applications. They can be found in construction, consumer products, engineering, kitchenware, tools, and more.

Black steel pipe fittings are widely used in various industries such as machinery, construction, petroleum, chemical industry, electric power, etc. In construction projects, black steel pipe fittings are often used to build brackets, bridges, shelves, etc.; in the field of mechanical processing, black steel pipe fittings are usually used to make Bearings, tires, etc.

Read more: Carbon steel vs Stainless steel