What is hot extruded seamless carbon steel pipe
Posted by zora li on November 7th, 2022
Hot extrusion billet of seamless carbon steel pipe can be forged billet, rolled billet, slab, billet centrifugal casting and so on. Short or long blank blank in the machine shop after peeling, sawing, drilling deep holes, after turning face and chamfering into the extrusion line.
Processed through the blank into the first washing machine for degreasing treatment before the annular heating furnace, and then into the annular heating furnace. Generally annular blank in a furnace heated to less than 900 ℃. But it can be heated directly to the seamless pipe extrusion temperature (for reaming without direct extrusion billet) according to process requirements. Then go to the vertical induction furnace for heating the material to the hot extrusion temperature. After heating the blank in a good dusting the outer bench painted a good glass frit, by the robot into the blank punch (expanded) in the cylinder bore, the glass powder is added after the blank ends of the "bell". Then, in legislation were red (expanded) hole piercing machine. After punching (expansion) of the hollow billet and the mold holes after exposure arising due to the temperature drop should be namely reheating heat up, but the impact of the glass frit billet surface reheating temperature detection, so that the heating temperature deviation, it is generally in to be reheated before removal, to remove the surface of the glass film blank, and then heated and the heated billet through the inner and outer surface of the rear glass powder coated by the ingot is fed into an extruder for the center for extrusion. After the completion of extrusion products and the press are separated by more than separating saws. Products and tools need to be appropriate cold treatment.
As we all know, hot extrusion cylinder for the interference multilayer tube fitted together, the amount of interference in the rational design, processing size in line with the premise of the drawings, the first warm-up before use, regular cleaning of the inner wall of the glass frit, and check the inner wall scratches under the circumstances, the general life in 5000 to 10 000 or more. Extrusion die with the longest contact time of the hot metal in the extrusion process, the life of a relative minimum. For the extrusion die longer life, general requirements, where possible squeeze faster, shorter cutting separation, to reduce the hot metal in the extrusion die residence time and extrusion die each should be checked and treated after extrusion, not only to ensure product quality, but also improve the extrusion die life. Since the piercing needle breaking small area when wrapped in hot metal extrusion, rapid temperature rise caused by the decline in the mechanical properties, it is necessary to provide sufficient cooling. Foreign steel extruder designed with internal cooling system is designed punch pin, but the effect is more general look. For the small size of the needle piercing cold hole greatly reduced the strength of the punch pin, it could easily lead to back needle hour break, while the large size of the piercing needle in terms of the cooling rate is too slow. Tunze company in the design 36MN stainless steel extruder, taking into account the small and medium size objects product products than it is not designed in the cooling system, but the design of a special cooling device for piercing needle piercing needle after the completion of the outer extrusion cold, and achieved good results, so that the service life of the punch pin from 10 to 30 times to more than 100 times, greatly improving the life of the punch pin.
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