CBIES AUTOMOTIVE|Requirements For The Production Process Of Seamless Steel Pipes
Seamless tubes are being used more and more widely in production and life. In recent years, the development of seamless tubes has shown a good trend. For the production of seamless tubes, it is also important to ensure their high-quality processing and production. CBIES professional auto parts export company has a very large number of seamless and welded tube products among its main products, which have been recognized by many manufacturers in recent years. Here CBIES gives you a brief introduction to the production process of seamless steel tubes for your understanding.
The production process of seamless steel pipe is mainly divided into two major steps.
A. Hot rolling (extruded seamless steel pipe): round pipe billet → heating → perforation → three-roll cross-rolling, continuous rolling or extrusion → peeling → sizing (or reducing) → cooling → straightening → hydro testing (or flaw detection) → marking → storage
The raw material for rolling seamless pipes is a round pipe billet. The round pipe embryo is cut with a cutting machine and grown out to a length of about 1 meter and transported to the furnace by a conveyor belt. The billets are fed into the furnace and heated to a temperature of approximately 1200 degrees Celsius. The fuel is hydrogen or acetylene and temperature control in the furnace is a key issue.
After the round tube billets have been discharged from the furnace, they must be pierced by a pressure perforator. Generally speaking, the more common perforator is the tapered roller perforator. This type of perforator has high production efficiency, good product quality, and a large perforation diameter extension for various steel grades. After perforation, the round pipe billet goes through cross-rolling, continuous rolling, or three-roller extrusion in turn. This is the step of seamless steel pipe forming, so it must be completed carefully. After extrusion, stripping and sizing are required. Sizing forms the tube by drilling holes in the billet through a cone that rotates at high speed. The inner diameter of the steel tube is determined by the length of the outer diameter of the sizer bit. After the steel tube has been sized, it enters a cooling tower where it is cooled by water jets. After the steel tube has cooled, it will be straightened. After straightening the tube is sent by conveyor belt to a metal detector (or hydro test) for internal flaw detection. Once the operation is complete, cracks, air bubbles, and other problems are detected if they are present inside the tube.
After quality inspection, the steel tubes are subjected to a rigorous manual selection process. After quality inspection, the steel tubes are painted with serial numbers, specifications, production batch numbers, etc., and lifted into the warehouse by crane. Be sure to ensure the quality and detailed process of seamless steel pipe operation.
B. Cold-drawn (rolled) seamless steel pipe: round pipe blank → heating → piercing → head → annealing → picking → oiling (copper plating) → multiple cold-drawn (cold-rolled) → round pipe → heat treatment → straightening → hydrostatic test (flaw detection) → marking → storage.
Among them, the rolling method of cold-drawn (rolled) seamless steel pipe is more complex than that of hot-rolled (extruded seamless steel pipe). The first three steps of its production process are basically the same. As a result, it is easier to operate. The difference is that from the fourth step onwards after the round pipe blank has been emptied, it needs to be tapped and annealed. After annealing, pickling is carried out using a special acidic liquid. After pickling, oil is applied. This is followed by multiple cold drawings (cold rolling) and special heat treatment. After the heat treatment, straightening is carried out. After straightening the tubes are sent by conveyor belt to a metal detector (or hydro test) for internal flaw detection. If there are cracks, air bubbles, and other problems inside the tube, they will be detected.
After these processes are completed, the steel pipe must pass a strict manual selection followed by a quality inspection. After quality inspection, the steel tubes are painted with serial numbers, specifications, production batch numbers, etc. After all this work is completed, they will be lifted by crane into storage.
The incoming seamless steel pipes are also carefully preserved and scientifically maintained to ensure that high-quality seamless steel pipes leave the factory at the time of sale.
