my country is a major wire rod producer, and its output ranks among the top in the world. Wires are widely used in communications, construction, power and other sectors. In wire production, drawing processing is the most commonly used processing method. The application range of drawing processing is very wide, mainly used for drawing straight materials such as bars and wires. Drawing production solves the problem of wire rods that are difficult to process by turning and other methods. Its processing accuracy is relatively high, and its processing speed is fast, the degree of waste to the blank is low, and the utilization rate is high. The wire drawing die is a very important consumable die in the drawing production of various metal wires. The cost of the wire drawing die accounts for more than 50% of the drawing cost. Currently, the commonly used wire drawing dies are alloy steel dies, cemented carbide dies and diamond dies, and various drawing dies have their own advantages and disadvantages in the use process. Now the working principle of the drawing die and the materials of the commonly used drawing die, the classification of the wear of the drawing die and the influencing factors of the drawing process are described below.

　　 The basic structure of wire drawing die

　　 The basic structure of the wire drawing die. The main working area of the wire drawing die is the inner hole. The inner hole structure can be divided into the entrance area,

　　, lubrication zone, sizing zone, exit zone five zones and follow the "smooth transition" theory, namely the wire drawing die hole

　　 The junction of the districts must be a small rounded transition. The drawn wire enters the drawing die from the entrance, and it acts on the drawing force i

　　 through the wire drawing die, and violent friction occurs on the tapered surface of the working area of the wire drawing die, and pull out from the exit to obtain a smaller wire.

　　 Wire drawing die size selection for each area

　　 (1) Entrance area

　　 The entrance angle of the inner hole of the wire drawing die is one of the important parameters. It must be ensured that the contact point of the wire entering the die occurs

　　 At the same height position in the reduction zone of the drawing die, and should be conducive to the entry of the wire. The entrance area of the drawing die provides a smooth profile leading to the lubrication area and the deformation area, so that the lubricant can reach the working surface of the drawing die.

　　(2) Lubrication area

　　The function of the lubrication area is to store lubricant and feed it into the work area. According to the difference of lubricant viscosity, wire diameter

The difference in 　　 and the length of the lubrication area, the cone angle of the lubrication area are different, so that the liquid lubricant can smoothly enter the working area and lubricate

The cone angle of the 　　 area should generally be selected at a larger value. If it is too small, the lubricant should not enter, and the lubricant will not flow, and even form a wedge-shaped blockage.

　　 If the cone angle of the lubrication zone is too large, the hydrodynamic pressure effect is not easy to form. The length of the lubrication zone will also affect the lubrication effect. Generally speaking, regardless of the lubrication method, the longer the lubrication zone, the better the lubrication effect.

　　（3）Working area

　　The working area is the area where the wire is plastically deformed. Its size parameters include the working area cone angle a and the working cone length h2. work

　　The cone angle a is the parameter of the drawing die, and the size of the cone angle a of the working area is related to the pressure acting on the inner hole of the drawing die and

　　 Its distribution law, the size of the drawing stress and the mechanical properties of the drawn wire play a decisive role.

　　The cone angle of the working area corresponding to the lowest drawing stress varies with the drawing environment, and there is an optimal working area cone angle range. When drawing

It is difficult to ensure that the wire axis is concentric with the axis of the inner hole of the wire drawing die. In addition, the inner hole of the wire drawing die is worn too much during the previous drawing, which leads to an increase in the diameter of the wire entering the inner hole. Both will cause the wire to deform outside the deformation zone, so work The length of the zone should be greater than the length of the actual deformation zone.

　　 (4) Sizing area

　　 The diameter of the sizing area is determined according to the allowable tolerance of the wire and the elastic deformation of the wire during drawing, and taking into account the service life of the mold, the negative tolerance size of the wire is usually selected.

　　 The following requirements should be met when determining the length of the sizing zone: sufficient wear resistance, energy consumed during drawing, and reduction of the possibility of wire breaking. Although the sizing zone is too long can increase the life of the wire drawing die, it will also cause friction, heat generation and energy consumption to increase, and it is easy to cause the diameter of the wire to be reduced or to break the wire. If the sizing area is too short, it will cause the wire to shake and produce a slub shape during drawing, and it will also cause the inner hole of the drawing die to wear quickly and cause the size to be out of tolerance. In general, the larger the diameter of the drawn wire, the shorter the length of the sizing zone.

　　（5）Exit area

　　The exit zone forms an angle of 90 degrees in the drawing die. Such an angle facilitates a wider exit, so that the drawing die can be restored to its original size many times without further processing. The export zone is often considered unimportant. But if the drawing die has no exit area, the trailing edge of the sizing belt will crack or peel off, causing damage to the drawing die