The drawing die is in the pressure processing of the carbide drawing die. Under the action of external force, the metal is forced to pass through the core of the drawing die, and the cross-sectional area of the metal is compressed to be compressed. However, to obtain the required cross-sectional area shape and size of wire drawing products, such as steel wire, copper wire. This technical processing method is called metal wire drawing process.
1. Problems caused by improper choice of work and angles.
When drawing the wire, the working setting angle is too large (equivalent to the compression rate is too small), so that the contact point of the wire entering the drawing die is too close to the sizing belt (for example, using a 14. die to produce a 16% compression rate). In this example, the deformation zone is relatively short, which speeds up the wire deformation rate and generates a lot of heat, which can easily lead to lubrication failure. If the cooling is extraordinary, it will affect the organizational structure of the wire, and increase the fear of tool consumption. If the mold angle is larger or the compression rate is smaller, the pressing contact will be closer to the warp belt. During the process of the wire moving to the warp belt first, it is difficult for the wire to smoothly transition to the sizing area due to the influence of the angle. The wire is concave, resulting in diameter reduction. If the strength of the material is too low, it will also cause diameter reduction or sympathy. Although the lubrication zone is relatively longer and provides good lubrication at the beginning, it will break the sliding pressure of the contact surface and produce a vortex washing effect, causing the interstitial powder to flow out of the die hole in the opposite direction, resulting in a weak smell and slip effect. The above-mentioned various undesirable effects caused by deformation eventually lead to lubrication failure. Surface cracks. Scratches, mold consumption aggravate, and wire diameter is difficult to control. The working taper angle is too small, causing the incoming line to be closer to the upper end of the work according to other points, which makes the deformation zone relatively longer. The residual work generated by the wire framer on the wire increases, and the Ministry of Measurement and Research has done so.
2. In addition, the lubrication area is small, and it has a strong moisturizing effect. At a certain point in the deformation area, the remaining wire surface will be exhausted. When the tensile stress is too large, the occupants in the fixed area will cause the expansion of the town, and the problems of shrinkage and circle of love will occur, and then lead to poor run-out, all of which are ring extension, wire breakage, overheating, and wire shrinkage.
3. Visualization of the middle fracture and herringbone pattern
Intermediate fractures and "person" cracks have been considered to be problems caused by raw materials after they were discovered. Intermediate fractures and "person" light lines are made by the tensioning process (large compression rate, large cargo path). Reasonably caused. In the process of pulling the online village, the internal organization of the online village extends along the same axis, and the flow of the organization on the surface of the online village is faster than the flow of the internal organization. Tensile stress of the same valley axis is generated in the heart, and when the tensile stress of the same tension exceeds the strength of the material, the character of "person" will be severely formed in the heart of the material. In severe cases, it will cause sorrow. Fracture (in volts), therefore, when formulating the right-handed craft, we should make rational use of the Anji drawing technique according to the raw materials and the type of drawing die. The established mold makes the relationship between the angle, the compression thing and the broken bag in the middle. According to the arrangement, the tensioning process can effectively prevent the occurrence of intermediate fractures and internal teaching schools (the white area in the circle is the middle fracture area, and the grid area is the city safety area). "
