Detailed classification of carbon steel

(1) Carbon steel can be classified into many types according to different uses. First of all, it can be divided into three categories: carbon structural steel, carbon tool steel and free-cutting structural steel. Among them, carbon structural steel can be further subdivided into two sub-categories: engineering construction steel and machine manufacturing structural steel. These different types of carbon steel have their own characteristics and advantages in specific application scenarios.

(2) The smelting method of carbon steel is also an important basis for classification. According to the different smelting methods, carbon steel can be divided into two categories: open-hearth steel and converter steel. Open-hearth steel is made by smelting raw materials such as pig iron and scrap steel in the open-hearth furnace, which has higher carbon content and better toughness. The converter steel is the steel obtained by smelting raw materials such as pig iron and scrap steel in the converter, which has high purity and good mechanical properties.

(3) In addition to the classification by smelting method, carbon steel can also be divided according to the deoxidation method. Common deoxidation methods include boiling steel, killed steel, semi-killed steel and special killed steel four types. Boiling steel refers to the rapid discharge of oxides in steel through high temperature heating, thereby reducing the content of inclusions; The kill steel refers to the control of heating temperature and time, so that the oxide in the steel is fully reduced to form fine granular inclusions; The deoxidation degree of semi-killed steel is between boiling steel and killed steel. The special killed steel refers to the special heat treatment process, so that the oxide in the steel is further reduced to achieve a higher deoxidation effect.

(4) In addition, carbon steel can also be classified according to its carbon content. According to international standards, carbon structural steel can be divided into low carbon steel (WC ≤ 0.25%), medium carbon steel (WC0.25%-0.6%) and high carbon steel (WC≥ 0.6%) three categories. Low carbon steel has low carbon content, good plasticity and toughness, and is suitable for the manufacture of structural parts with low strength requirements; Medium carbon steel has moderate carbon content, has a certain strength and good machinability, and is suitable for manufacturing parts with medium requirements; High carbon steel has higher carbon content, higher hardness and strength, and is suitable for manufacturing parts with higher strength requirements.

(5) Finally, according to the quality characteristics of carbon steel, we can also subdivide them into four categories: ordinary carbon steel, high quality carbon steel, high quality steel and extra high quality steel. Ordinary carbon steel contains higher phosphorus and sulfur elements, so it has a certain corrosion; High-quality carbon steel is optimized in terms of phosphorus and sulfur content to reduce corrosion; The high quality steel further reduces the content of phosphorus and sulfur, and improves the performance of steel; The extra high quality steel uses a more stringent production process and material selection, with the highest quality standards and performance.

To sum up, the classification of carbon steel according to factors such as use, smelting method, deoxidation method and carbon content can help us better understand and apply different types of carbon steel products to meet the needs of different fields and scenarios.