(1) Carbon steel can be divided into three categories according to its use: carbon structural steel, carbon tool steel and free-cutting structural steel. Carbon structural steel is further divided into two types: engineering construction steel and machine-made structural steel;

(2) According to the smelting method, it can be divided into open hearth steel and converter steel;

(3) According to the deoxidation method, it can be divided into boiling steel (F), killed steel (Z), semi-killed steel (b) and special killed steel (TZ);

(4) According to the carbon content, carbon 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%);

(5) According to the quality of the steel, carbon steel can be divided into ordinary carbon steel (higher phosphorus and sulfur content), high-quality carbon steel (lower phosphorus and sulfur content) and high-grade high-quality steel (lower phosphorus and sulfur content). ) and special grade high quality steel.