Carbon steel bar is a commonly used metal material, mainly composed of iron and carbon, which is processed into a rod-shaped steel product through forging, rolling and other processes. According to the carbon content, carbon steel bars can be divided into low carbon steel, medium carbon steel and high carbon steel, suitable for different purposes. Due to the excellent mechanical properties, processing performance and low cost of carbon steel, carbon steel bars are widely used in construction, automobile, machinery manufacturing and other fields.