Cold drawing machine is a process in which metal is drawn without being heated. It can be used to shape the cross-section of a bar or rod, and it is often preferable to hot extruded parts because they are more precise and have better surface finish. Cold drawing can also be used to draw metals that would not be able to be extruded because of their strength requirements or their ductility limitations. The advantages of this process are lower costs and higher accuracy. It also produces a better quality product with less material waste.
Before drawing, the raw stock is submerged in a lubricant to prevent friction and improve its machinability. It may require several passes through the die to achieve the desired diameter and length. The steel bars may also need to be annealed after each pass. The cold-drawn steel is more resistant to corrosion than rolled or hot-rolled steel and has better mechanical properties.
The process of drawing is a complex mechanical process that influences the change in tensile and yield strength of the metal under stress. The changes in these indicators depend on a large number of technological parameters, such as the drawing speed, the design of the drawing route, and the die half-angle. In addition, they are affected by the quality of the lubrication and the quality of the surface preparation of the die and the wire rod.
To reduce the energy required for the drawing process, it is necessary to improve the lubrication of the steel wire rod and to reduce the contact area between the steel and the dies. This can be done by using different types of dies and by changing the design of the lubrication system. Changing the die half-angle can also improve the conditions for injecting the technological lubricant into the deformation zone.
In order to make the drawing process more efficient, a computer program has been developed that calculates the energy-power parameters of the process for any given drawing route. The calculation results are compared to experimental data. The program can be adjusted to various kinds of drawing machines.
The main components of a drawing machine include a feeding table, receiving tank frame, push rod device, core rod lifting platform, mandrels front and back adjusting devices, body, drawing trolley, discharge conveying chain device, and an automatic collecting rack for the finished products. The machine can be powered by hydraulic cylinders or chains. It can also be controlled by an industrial control unit.
To prepare the rods for drawing, metalworking companies submerge them in a lubricant to make it easier for them to pass through the die. The lubricant also helps the rods to retain their shape. A calamine stripping machine is sometimes used to remove a thin layer of calamine from the rods. This step is important because if the calamine remains on the rod, it can cause it to break during the drawing process. In addition, removing the calamine will help to make the drawing more fluid and efficient.