The hot extruded blanks of seamless steel tube can be forged blank, rolled blank, slab, centrifugal casting of billet, etc. After peeling, sawing and drilling deep holes, after turning and chamfering into the extrusion line, the blanks in the machine shop are short or long.


The billet is processed into the first washing machine for degreasing before the annular heating furnace, and then into the annular heating furnace. Generally, the annular blank is heated to below 900 C in the furnace. However, according to the process requirements, it can be directly heated to the extrusion temperature of hot steel (for the expansion of blanks without direct extrusion). Then enter the vertical induction furnace and heat the material to the hot extrusion temperature. After the billet is heated, a good layer of glass is coated on the working table outside, and the hollow punch (expansion) in the cylinder hole is entered by the robot. Glass powder is added after the "bell" blank end. Then, in legislation is the red (extended) punch. The hollow billet and die hole after punching (expansion) should be reheated and heated because of the temperature drop. But the influence of glass billet on the surface reheating temperature is detected, so that the heating temperature deviation is usually reheated before removal, the surface of glass film billet is removed, and then the heated billet is heated and passed through the post-glass powder coated by the ingot. The inner and outer surfaces are fed into the extruder for use in the extrusion center. After the extrusion product is finished, the press is separated by several separating saws. Products and tools need to be properly cooled.


It is well known that the hot extrusion cylinder is assembled for the interference multilayer tubes, the interference is reasonably designed, the processing size meets the drawing premise, preheating before use, cleaning the glass material on the inner wall regularly, and inspecting the scratches on the inner wall, the general life is between 5000 and 10000. The contact time between the extrusion die and hot metal is the longest and the service life is the smallest. As for the long life of extrusion die, it is generally required that the extrusion die should be extruded faster and the cutting spacing shorter when possible. The residence time of hot metal in the extrusion die and the service life of the extrusion die should be checked and treated after each extrusion, not only to ensure the product quality, but also to improve the service life of the extrusion die. Due to the small breakage area of the puncture needle during hot metal extrusion and the sharp rise of temperature caused by the decrease of mechanical properties, it is necessary to provide adequate cooling. The foreign steel extruder designed with internal cooling system has a punch, but the effect is more general. For small needle piercing cold hole size greatly reduces the strength of the punch needle, it is easy to cause the back needle hour breakage, and large needle piercing in cooling speed is too slow. When designing 36MN stainless steel extruder, Tunze Company designed a special cooling device for extrusion cooling of puncture needle after puncture needle completion, taking into account that the products of small and medium-sized objects were not designed in the cooling system, and achieved good results. The service life of the puncture needle ranged from 10 to 30 times to more than 100 times, which greatly increased the service life of the puncture needle.