Hard Alloy Extrusion Press According To Process
Hard Alloy Extrusion Press According to process
When extruding the pipe, it can be carried out on a cemented carbide extruder with an independent perforation device or on a cemented carbide extruder without a separate perforating device. At the time of extrusion, the perforations pass through the axis of the ingot along the axis of the ingot and insert into the die hole to form a ring. With the pressure of the extrusion shaft, the metal is forced through the die hole to form the pipe, whose diameter depends on the diameter of the punch , And the outer diameter depends on the diameter of the extrusion die hole.
Positive extrusion production of pipe, according to the needs of the process, you can use the hollow billet production, can also be used solid ingot in the carbide extrusion machine for perforation extrusion. The use of hollow ingot extrusion pipe increases the billet drilling a large number of additional processing, the ingot in the heating of the inner surface is also oxidized, easily lead to extrusion pipe surface defects. So the use of this method is not economical to produce pipe, generally only in the production of small size pipe, only use this method. In modern extrusion techniques, tubing is typically extruded with a cemented carbide extruder with a separate perforation device. When the pipe is produced in this way, a part of the metal is ejected into a waste "radish head", and it is very economical to produce a large diameter pipe. Therefore, other methods to reduce the loss of the "radish head" are to improve the yield Important means. Such as: for some size of the large tube material head, as long as you can meet the requirements of other extrusion cylinder system, can be used as a billet for the production of small size products. In addition, you can also use the joint extrusion method to reduce the loss of perforated material head to improve its yield.
When the pipe is squeezed, there is a certain friction between the perforated needle and the metal ingot, which flattens the uneven flow of the metal during the extrusion process. So squeeze the pipe, the tail is generally shorter. The main defects of the extruded pipe are inside and outside the surface defects, such as: pipe inside and outside the surface of the oxide pressure, scratches, bubbles, from the skin, pipe wall thickness uneven (eccentric) and so on. In order to prevent the extrusion process in the oxidized skin products, you can also use peeling extrusion method, modern extrusion technology for pipe extrusion application is more common. Such as: high-precision Ying brass, all kinds of condensing tube, waveguide and other alloys. In order to ensure that the extruded products out of the die hole does not produce high temperature oxidation, you can use water seal extrusion technology to protect the atmosphere extrusion method. In the horizontal carbide extrusion machine using perforated needle extrusion pipe one of the most important quality problems, is the pipe eccentric problem. There are many factors that affect the eccentricity of the extruded pipe, but mainly because of the reasons for squeezing equipment and tools, ensuring the concentricity of the mechanical concentricity of the cemented carbide extruder and the concentricity of the extrusion tool (shaft, cylinder, mold base) Extruded pipe wall thickness uniformity of the primary conditions. The specific situation should also be based on the equipment used in the production and practice of the experience accumulated to solve.