Cold drawing is a process that can increase the strength of steel by realigning its molecules. This increases the material’s tensile and flexural strength. It also helps to reduce its brittleness. The process can be used to create complex shapes that cannot be achieved with hot rolled steel. The process is performed by pulling the steel through carbide dies that have been contoured to the desired shape. This process can be repeated as many times as needed to achieve the desired length and width of your part.
The raw materials for cold drawing are typically hot rolled bar or rod coils. These products have a rough and scaled surface, which needs to be cleaned prior to the drawing process. A drawing lubricant may be applied to the surface as well. The lubricant can help prevent the metal from sticking to the dies and it can improve the drawing process.
After the cleaning and lubrication steps, the material is drawn in a series of dies to reduce its size and shape. The material is often annealed between each drawing to soften it and promote proper adhesion to the die. The annealing process can also help to modify the microstructure, mechanical properties and machining characteristics of the product. It can be done before, during (between draws), or after the drawing process, depending on the material requirements.
The different varieties of draw machines include fixed and floating plug. Fixed plug drawing produces a smooth ID and is ideal for low-to-medium area reductions. The machine requires a single operator and operates with a mandrel that is fixed in position. It can be operated using manual or pneumatic control. Floating plug drawing is similar to fixed plug drawing except that the mandrel can be moved in and out of the dies. This is a more flexible option than fixed plug drawing and is especially useful for high-quality requirements.
The calculation method for energy-power parameters of drawing routes relies on the application of a mathematical model that can be implemented in software form. The program can be used to quickly and fairly accurately estimate the drawing forces along a given route. It is based on the mechanical properties of the material being drawn, its tendency to harden during cold deformation and the friction coefficient at the metal-wire contact point. It also takes into account the design parameters of the drawing dies. The calculated drawing force is compared with the experimental ones to determine the validity of the model and its adequacy for designing wire drawing routes. The error between the calculated and experimental drawing forces does not exceed 4-9%. This is a reasonable value for this type of work. The accuracy of the model is a prerequisite for the correct selection of a drawing machine and the design of wire production lines. This is a crucial aspect of economic and technological efficiency. It is also important for the reliability and long-term stability of a production line. Cold drawing machine