Comparison of hole shapes of wire drawing dies in China and abroad

       Compared with foreign products, domestic wire drawing die blanks have the following obvious shortcomings:
①The entrance angle is small. Since the wire first contacts the die core entrance area during the drawing process, the taper angle of the entrance area is small, which not only increases the contact area between the wire and the inner hole, increases the friction force, but also hinders the introduction of lubricant, making the drawing process The lubrication effect in the medium becomes worse, which seriously affects the service life of the mold.
The entrance angle of foreign wire drawing die products is increased, which effectively avoids the abrasion between the wire and the wire drawing die, and brings in more lubricant, which enhances the lubrication effect and reduces die core wear. This change improves the surface quality of the wire and also improves the service life of the wire drawing die. ②The working area is short. Compared with domestic wire drawing dies of the same specification, the working area of foreign wire drawing dies is generally much longer. A longer working area is conducive to the reduction and uniform distribution of friction in the wire drawing process, reduces the wear of the inner hole of the wire drawing die, and improves the life of the die. A longer and narrow working area can reduce the gap between the wire and the drawing die, and can force more lubricant into the middle of the wire and the inner hole under high pressure, resulting in better lubrication pressure. The temperature of the wire exiting from the inner hole is lower, the drawing force is reduced, and the metal flow is more uniform during the drawing process, which is beneficial to the improvement of the drawing speed and the improvement of the wire surface quality. In addition, this type of work area design can prevent lubricant from exiting from the inlet end of the drawing die.
Due to the short working area of the mold in my country, the effective use area in the hole is small, which not only increases friction and aggravates wear, but also wastes raw materials and increases cost input.
③The sizing area is not obvious. The sizing area is the final link to determine the final size of the wire. The short and unevenness of the sizing area will directly affect the final quality of the wire. The short sizing belt is likely to cause the product size to be out of tolerance, and the drawing die will wear out quickly. The obvious and straight sizing zone can produce high-precision and high-quality wire rods, and is beneficial to reduce wear and greatly increase the service life of the wire drawing die.
From the comparison of the wear curves of the wire drawing die made in Germany and the wire drawing die made in Hunan Steel, the two wire drawing dies work under the same drawing conditions: Workpiece material: 65 gauge steel wire; drawing speed: 3.64m/s; drawing Lubricant: soap powder; surface coating before drawing: sulfuric acid pickling, phosphating, borax coating. The test results show that the structure of the drawing die has a great influence on the use of the drawing die. The service life of the German-made wire-drawing die is 2.72 times longer than that of the Xianggang-made wire-drawing die.
The above-mentioned comparative analysis proves that the hole type optimization of the inner hole of the wire drawing die can reduce the wear rate of the wire drawing die and prolong the service life of the wire drawing die. Therefore, optimizing the hole shape of the drawing die and improving the manufacturing accuracy of the drawing die can save production costs and greatly improve production efficiency, which is of great significance to the development of my country's wire industry