Steel can be divided into low carbon steel, medium carbon steel and high carbon steel.
The carbon content of low carbon steel is generally less than 0.25%;
Medium carbon steel-carbon content is generally between 0.25-0.60%;
The carbon content of high carbon steel is generally greater than 0.60%.
Except for carbon (C) and a certain amount of silicon (Si) (generally not more than 0.40%) and manganese (generally not more than 0.80%, up to 1.20%), steel contains no other alloying elements (except residual elements).
Steel with carbon content below 2. 1% and iron with carbon content above 2. 1%.
The higher the carbon content in steel, the worse the toughness, and the higher the carbon content in iron, the better the toughness.