Preparation method of carbon steel pipe

The raw material for carbon steel pipes is a round tube blank, which must be cut and processed using a cutting machine to form billets approximately one meter in length. These billets are then conveyed via a conveyor belt into a furnace for heating. The furnace heats the billets to around 1200 degrees Celsius, with hydrogen or acetylene serving as the fuel. Temperature control within the furnace is a critical aspect of the process. Once the round tube billets exit the furnace, they undergo piercing by a pressure piercing machine. A commonly utilized type is the conical roller piercing machine, known for its high production efficiency, superior product quality, significant perforation and expansion capabilities, and versatility across different steel grades. Following the piercing, the round tube blanks are subjected to rolling, continuous rolling, or extrusion by a set of three rollers. After being squeezed, the pipes require detachment and sizing. The sizing machine features a conical drill bit that rotates at high speed to bore into the steel billet, forming a steel pipe. The inner diameter of the steel pipe is determined by the external diameter of the sizing machine’s drill bit. Subsequently, the steel pipe is directed into a cooling tower where it is cooled by water spray. After cooling, the steel pipes are straightened. They are then conveyed to a metal inspection machine (or hydraulic tester) for internal examination. Any defects such as cracks or bubbles within the steel pipe will be detected during this stage. After passing the quality inspection, the steel pipes undergo rigorous manual selection. Finally, details including the quantity, specifications, production batch number, etc., are painted onto the steel pipes, which are subsequently lifted into storage by a crane.