Cold upsetting and cold extrusion are basically the same deformation processing conditions, but the operation mode is different. Cold pier is a kind of forging deformation of small workpiece, which is often used in fastener industry. However, cold extrusion is a kind of extrusion deformation of large workpieces, which is widely used.
What is cold extrusion？
Cold extrusion is to place the metal blank in the cold extrusion die cavity, at room temperature, through the punch fixed on the press to exert pressure on the blank, making the metal blank produce plastic deformation and the processing method of parts. Obviously, the cold extrusion process depends on the mold to control the metal flow, and relies on a large number of metal volume transfer to form parts. In terms of extrusion equipment, China has the ability to design and manufacture various tonnage extrusion presses. In addition to the general mechanical press, hydraulic press and cold extrusion press, the friction press and high-speed and high-energy equipment are successfully used for cold extrusion production.
If the blank is extruded without heating, it is called cold extrusion. Cold extrusion is one of the processing technologies of no chip and less chip parts, so it is an advanced technology in the plastic processing of metal chips. If the blank is heated to the temperature below the recrystallization temperature for extrusion, it is called warm extrusion. Warm extrusion still has the advantage of less chips.
Cold extrusion technology is an advanced production technology with high precision, high efficiency, high quality and low consumption, which is widely used in large-scale production of medium and small forgings. Compared with hot forging and warm forging, it can save 30% ～ 50% of material and 40% ～ 80% of energy. Moreover, it can improve the quality of forgings and improve the working environment.
At present, cold extrusion technology has been widely used in fastener, machinery, instrumentation, electrical appliances, light industry, aerospace, shipbuilding, military industry and other industrial sectors, and has become one of the indispensable important processing methods in metal plastic bulk forming technology. With the progress of science and technology and the continuous improvement of product technical requirements in automobile, motorcycle, household appliances and other industries, cold extrusion production technology has gradually become the development direction of refined production of small and medium-sized forgings.
Cold extrusion is also divided into forward extrusion, backward extrusion, compound extrusion, radial extrusion and so on.
What is cold heading？
Cold heading process is one of the new technologies of less cutting metal pressure machining. It is a kind of processing method that uses the plastic deformation of metal under the action of external force and makes the metal volume redistributed and transferred with the help of mould, so as to form the required parts or blank. The cold heading process is most suitable for the production of bolts, screws, nuts, rivets, pins and other standard fasteners. The equipment commonly used in cold heading process is a special cold heading machine. If the production is not too large, it can also be replaced by crank press or friction press.
Because of its high productivity, good product quality, greatly reducing material consumption, reducing production cost and improving working conditions, cold heading technology is more and more widely used in mechanical manufacturing, especially in the production of standard fasteners. The most representative products produced by multi station cold heading machine are bolts, screws and nuts.
Is cold heading and cold extrusion the same thing?
Cold block and cold extrusion are basically the same deformation processing conditions, but the operation mode is different. Cold pier is a kind of forging deformation of small workpiece, which is often used in fastener industry. Cold extrusion belongs to the extrusion deformation of larger workpieces and is widely used; cold upsetting is equivalent to a branch of cold extrusion. Simply speaking, in the process of bolt making, hexagon head forming belongs to cold upsetting, and rod diameter reduction belongs to cold extrusion (forward extrusion). There are both cold upsetting and cold extrusion for non chamfered hexagon flange bolts (multi position forming). The front side shaping of hexagon nut is only cold upsetting, while the hole extruding in the later process belongs to cold extrusion (forward and backward extrusion).