In the production of steel wire, the consumption of wire drawing dies can be broken or worn. Broken molds can only be scrapped, and worn molds can be repaired and reused. Therefore, the proportion of broken molds should be reduced as much as possible in production. Statistics show that the mold core rupture forms: (1) Longitudinal cracks, 75% of the ruptured molds are longitudinal cracks, 90% of which are normal damage caused by the thinning of the core wall after repeated grinding, and only a small part is due to The drawing reduction rate is too large, the oxide scale on the surface of the steel wire is not cleaned, the coating is not good, and the mold installation is not good; (2) transverse cracks, accounting for about 13% of the total, the transverse cracks are mainly caused by the failure of the mold installation Good, such as the mold core taper or out of round is too large, caused by poor contact between the mold core and the bottom surface of the mold sleeve. Excessive drawing reduction rate and poor hole slippage are the secondary reasons; (3) Cracks and breakage at the outlet end accounted for 6% respectively. Mold material defects and improper drawing processes accounted for half of each, and the meat loss was mainly due to mold quality problems. There are three manifestations of die hole wear. (1) The surface is rough. The deformation heat generated by the wire drawing causes the temperature of the mold to rise, and local oxidation color appears, causing slight wear. Poor lubrication leads to spot welds between the steel wire and the die hole surface, the tungsten carbide particles loosen, and the displacement forms scratches and ripples. The surface of the working cone and the sizing belt is rough and has a lot of wear. (2) Ellipse. The hardness of cemented carbide is uneven, the drawing direction does not coincide with the axis of the die hole, and excessive force on one side of the die hole will cause an ellipse. (3) Annular groove. It is a typical fatigue wear. During the drawing process, the die hole continuously bears the impact of the wire, which loosens the tungsten carbide particles and forms a rough surface. The rough surface scrapes metal chips from the surface of the steel wire. Finally, an annular groove is formed in the area where the die hole bears the greatest impact force. From oxidation discoloration to surface roughness, the appearance of ring grooves is a process of increasing wear. Reasonable use of molds, the way to extend the life of the mold is to grind it in time and replace the mold before the ring groove appears in the mold hole. The mold should be cleaned and inspected in time after each use. If the surface is slightly worn, it can be directly polished or finely ground. After polishing, it can be used as a process mold. Try to control the amount of mold grinding to the minimum level and increase the number of mold repairs and reuses. According to GB/T 6110, when the diameter of the die hole is close to the maximum diameter of the die blank of this size, more attention should be paid to the surface of the die hole, even if there are slight lines, it must be scrapped to prevent wire waste. The life of the die is usually measured by the number of meters or the quality of the steel wire drawn when the wear is 0.01 mm. For the medium-sized (04.0mm) special steel wire, the life value of the carbide die can generally reach 300,000 m/0.01 mm. the above. Mould consumption is usually expressed by the mass of cemented carbide mould core consumed per ton of steel wire. The mould consumption index of special steel wire is about 150-250g/t. More details,pls contact Toby, E-mail:sales-manager302 at wococarbide.com.
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