(2) according to smelting method, it can be divided into open hearth steel and converter steel;
(3) According to the deoxidation method can be divided into boiling steel (F) killed steel (Z) semi-killed steel (B) and special killed steel (TZ);
(4) according to carbon content can be divided into low carbon steel (0.25% WC) to carbon steel, medium carbon steel (WC0.25%0.6%)and high carbon steel (WC> 0.6%).
(5) according to the quality of steel, carbon steel can be divided into ordinary carbon steel (phosphorus and sulfur higher) high quality carbon steel (phosphorus and sulfur lower) and high quality steel (phosphorus and sulfur lower) and super high quality steel.