Low carbon steel is a group of steels whose carbon content is less than a maximum limit determined by various standards. These types of steels have lower strength and hardness than other medium and high carbon steels, but they can be formed well. Sheets are the most important steel sections made from these steels, an example of which is black sheet. Below, we will mention the most important properties, specifications and applications of these steels.

What is low carbon steel?
Low carbon steels are steels whose carbon content is usually less than 0.3%. Of course, it should be noted that these steels themselves are also divided into two categories. Although they are all low carbon steels. These two categories include Low Carbon Steel and Mild Steel.

According to the ASTM standard, low carbon steels have less than 0.15% carbon. In contrast, mild steel is a type of low carbon steel with a carbon content between 0.15 and 0.3 percent. Therefore, these two names are only to differentiate the range of carbon present in their chemical composition and both refer to low carbon steels.

High-strength, low-alloy (HSLA) steels are also often classified as low carbon steels, but they also contain other elements such as copper, nickel, vanadium, and molybdenum. Together, these elements make up up to 10 percent by weight of the steel content.

High-strength, low-alloy steels, as their name suggests, have higher strength, which is achieved by heat treatment. They are also ductile and can be easily formed and machined. Low-alloy and high-strength steels are more resistant to corrosion than plain low carbon steels. To learn about the types of low alloy steels, visit this page.

Characteristics and properties
The most important properties of low-carbon steels, which are due to the presence of these low carbon amounts in their structure, include low strength, low hardness and high flexibility. Also, these types of steels cannot be hardened by heat treatment because martensite is not formed in sufficient quantities due to the low carbon content in them. Therefore, they must be subjected to cold working to increase their strength.

The microstructure of low-carbon steels often includes ferrite and pearlite, which are soft and flexible phases but do not have high strength and hardness. Proper machinability and welding due to the absence of cracks and embrittlement in these steels are another of the most important properties of low-carbon steels. In addition, low production cost is also one of the most important advantages of this type of steel.

The most important grades of low carbon steel
The most important standard grades of low carbon steel, from which most steel sheets are made, include A36, A283, A516, A572, and also A83 or 1020 steel. Each of these grades has medium strength, high ductility, and low weight, which is due to the low carbon content and other alloying elements in them. The table of mechanical properties and chemical composition of the most commonly used grades of low carbon steel is given below. Learn about the specifications of A36 steel in this link.