Carbon steel sheet

※   Low carbon steel (C≤0.25%) : carbon steel with carbon content less than 0.25%, because of its low strength, low hardness and soft, it is also called soft steel. It includes most of the ordinary carbon structural steel and a portion of high-quality carbon structural steel, most of which are not heat treated for engineering structural parts, and some are carburized and other heat treated for mechanical parts requiring wear resistance. Low hardness, good plasticity, easy to use cold plastic deformation molding process, welding and cutting, often used in the manufacture of chains, rivets, bolts, shafts and so on.

※   Medium carbon steel (C is 0.25-0.6%) : good hot working and cutting performance, poor welding performance. The strength and hardness are higher than low carbon steel, while the plasticity and toughness are lower than low carbon steel. Without heat treatment, directly use cold rolled materials, cold drawn materials, can also be used after heat treatment. The medium carbon steel after quenching and tempering has good comprehensive mechanical properties. The highest hardness that can be achieved is about HRC55 (HB538), σb is 600 ~ 1100MPa. Therefore, in the various uses of medium strength level, medium carbon steel is the most widely used, in addition to as a building material, but also a large number of used in the manufacture of various mechanical parts.

※   High carbon steel (C > 0.6%) : after proper heat treatment or cold drawing hardening, it has high strength and hardness, high elastic limit and fatigue limit, and the machinability is acceptable, but the welding performance and cold plastic deformation ability are poor. Due to the high carbon content, cracks are easy to occur during water quenching, so dual-liquid quenching is mostly used, and oil quenching is mostly used for small-section parts. This type of steel is generally used after quenching by tempering or normalizing at medium temperature or in a surface quenched state. Mainly used for the manufacture of springs and wear parts, high carbon steel density 7.81g/cm³. Can be used in the production of fishing gear.