Advantages of high carbon steel:
1. High hardness (HRC60-65) and good wear resistance can be obtained after heat treatment.
2. When annealing, the hardness is moderate and the workability is good.
3. Raw materials are readily available and the production cost is low.


Defects of high carbon steel:
1. Poor thermosetting. When the working temperature of the tool is higher than 200 degree C, its hardness and wear resistance decrease sharply.
2. Low hardenability. The diameter of fully hardened water quenching is usually only 15 to 18 mm; the diameter or thickness of fully hardened oil quenching (95% martensite) is only 6 mm, and it is easy to deform and rupture.


The hardness and strength of high carbon steel mainly depend on the amount of dissolved carbon in the steel, which increases with the increase of solid carbon content. When the solid solution carbon content exceeds 0.6%, the hardness will not increase after quenching, but the wear resistance of steel will increase slightly with the increase of excess carbide content, while the plasticity, toughness and elasticity will decrease. Therefore, according to the use conditions and strength and toughness of steel, different kinds of steel are often used. For example, in order to form spring or spring loading components with lower pressure, lower carbon 65 steel can be selected. Usually, high carbon steel can be produced by electric furnace, open hearth furnace and oxygen converter. When high quality or special quality is needed, electric furnace smelting plus vacuum self-consumption or electroslag remelting can be used. In smelting, the chemical composition, especially the content of sulfur and phosphorus, should be strictly controlled. In order to reduce segregation and improve isotropic properties, high temperature diffusion annealing (especially for tool steels) can be performed on ingots. In hot working, the stop forging (rolling) temperature of hypereutectoid steel is low (about 800 C). After forging and rolling, the precipitation of coarse network carbides should be avoided. Slow cooling should be adopted to prevent thermal stress below 700 degree C. Cause cracks. Prevent surface decarburization during heat treatment or hot working (especially for spring steel). Sufficient compression ratio must be provided to ensure the quality and properties of steel during hot working.