Hainan Steel Supermarket

Introduction to High Quality Carbon Structural Steel

High quality carbon structural steel is a carbon steel with a carbon content of less than 0.8%. This steel contains less sulfur, phosphorus, and non-metallic inclusions than carbon structural steel, and has better mechanical properties.

High quality carbon structural steel (GB/T699-1999):Except for containing carbon (C) element and a certain amount of silicon (Si) (generally not exceeding 0.40%) and manganese (Mn) (generally not exceeding 0.80%, with a higher value of up to 1.20%) alloy elements for deoxidation, the steel does not contain other alloy elements (excluding residual elements).

Classification of high-quality carbon structural steel

This type of steel relies on adjusting the carbon content (C) to improve its mechanical properties. Therefore, according to the level of carbon content, this type of steel can be further divided into:

Low carbon steel - with a carbon content generally less than 0.25%, such as 10, 20 steel, etc;

Medium carbon steel - The carbon content is generally between 0.25 and 0.60%, such as 35, 45 steel, etc;

High carbon steel - The carbon content is generally greater than 0.60%. This type of steel is generally not used for manufacturing steel pipes.

In fact, there is no clear boundary between their carbon content.

This type of steel must ensure both chemical composition and mechanical properties. The content of sulfur (S) and phosphorus (P) impurity elements is generally controlled below 0.035%. If it is controlled below 0.030%, it is called high-grade high-quality steel, and its grade should be followed by ' A ' , such as 20A;

If P is controlled below 0.025% and S is controlled below 0.020%, it is called special grade high-quality steel, and ' E ' should be added after its grade to indicate the difference.

For other residual alloy elements brought into steel by raw materials, such as chromium (Cr), nickel (Ni), copper (Cu), etc., the content is generally controlled at Cr ≤ 0.25%, Ni ≤ 0.30%, and Cu ≤ 0.25%.

High quality carbon structural steel is divided into two groups based on its manganese content:normal manganese content (0.25% -0.8%) and high manganese content (0.70% -1.20%). The latter has good mechanical and processing properties.

High quality carbon structural steel usage

This type of steel has a large production capacity and a wide range of uses. It is generally rolled (forged) into circular, square, flat and other profiles, plates, and seamless steel pipes. Mainly used for manufacturing general structural and mechanical components, as well as building structural components and pipelines for conveying fluids. According to usage requirements, sometimes heat treatment (normalizing or tempering) is required before use.

1. Hot rolled high-quality carbon structural steel sheets and strips

High quality carbon structural steel hot-rolled steel sheets and strips are used in the automotive, aviation, and other industries. The steel grades are boiling steel:08F, 10F, 15F; Killed steel:08, 08AL, 10, 15, 20, 25, 30, 35, 40, 45, 50. 25 and below are low-carbon steel plates, and 30 and above are medium carbon steel plates.

2. High quality carbon structural steel hot-rolled thick steel plates and wide steel strips

High quality carbon structural steel hot-rolled thick steel plates and wide steel strips are used for various mechanical structural components. The grades of its steel are low-carbon steel, including:05F, 08F, 08, 10F, 10, 15F, 15, 20F