Carbon steel is an iron-carbon alloy with a carbon content of 0.0218% to 2.11%. Also called carbon steel. Generally also contains a small amount of silicon, manganese, sulfur, phosphorus. the higher the carbon content in carbon steel, the greater the hardness and the higher the strength, but the lower the plasticity.

The hot-rolled steel coil is made of continuous casting slab or pre-rolled slab as raw material, heated by a walking heating furnace, descaled by high-pressure water, and then entered into the rough rolling mill. Computer-controlled rolling, after final rolling, laminar cooling (computer-controlled cooling rate) and coiling by a coiler become straight rolls.

Seamless steel pipe for structure (GBT8162-2008). Mainly used for general structure and mechanical structure. Its representative material (brand): carbon steel, 20, 45 steel; alloy steel Q345, 20Cr, 40Cr, 20CrMo, 30-35CrMo, 42CrMo, etc. 2. Seamless steel pipes for conveying fluids (GBT8163-2008). It is mainly used for conveying fluid pipelines in engineering and large-scale equipment. The representative material (grade) is 20, Q345, etc. 3. Seamless steel pipes for low and medium pressure boilers (GB3087-2008) are used to manufacture various structures of low and medium pressure boiler superheated steam pipes, boiling water pipes and superheated steam pipes, large smoke pipes, small smoke pipes and arch bricks for locomotive boilers Hot-rolled and cold-drawn (rolled) seamless steel pipes of high-quality carbon structural steel for pipes. The representative material is 10, 20 steel.