High Quality Q235 Grade D Ss400 S235jr S235jo S235j2 X42 Cold Old Drawn Seamless Carbon Steel Pipes

　　Seamless carbon steel pipes are made of steel ingots or solid billets through perforation to make capillaries, which are then hot-rolled, cold-rolled or cold-drawn. The raw material of carbon steel pipe is a round tube blank, which is cut by a cutting machine into a billet with a length of about 1 meter, and sent to a furnace for heating through a conveyor belt. The billets are fed into the furnace and heated at about 1200 degrees Celsius. The fuel is hydrogen or acetylene. Furnace temperature control is a critical issue. After the round tube blank is released from the furnace, it is pierced through a pressure punching machine. Generally, the more common punching machine is the conical roller punching machine. This kind of punching machine has high production efficiency, good product quality, large amount of perforation and diameter expansion, and can wear a variety of steel grades. After perforation, the round tube blank is successively cross-rolled, continuously rolled or extruded by three rolls.

　　1. 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.