(1) The drawing surface shrinkage rate of the drawing die is too large, causing cracks or breakage of the die. Most of the cracks or broken cracks are caused by the release of internal stress. In any material structure, the existence of internal stress is inevitable. The internal stress that occurs when the wire is drawn can enhance the microcrystalline structure of the mold, but when the drawing surface shrinkage is too large, it cannot be smoothed in time, and the temperature rise is too high, it will cause the mold It is indicated that part of the material is removed, and the stress received by the microcrystalline structure is greatly increased, making it easier to crack or break.
(2) The drawing axis of the wire is asymmetrical to the center line of the die hole, resulting in uneven stress on the wire and drawing die, and the impact of mechanical vibration will also cause a high stress peak on the wire and drawing die. Both Both will accelerate the wear of the mold.
(3) The wire drawing die is formed due to uneven annealing and the wire hardness is not uniform. The simple composition of the diamond drawing die is premature fatigue damage, forming an annular groove, and increasing die hole wear.
(4) The surface of the wire is rough, and the surface adhesion of oxide layer, sand or other impurities will cause the mold to wear out too quickly. When the wire passes through the die hole, the hard and brittle oxide layer and other adhering impurities will form the die hole of the drawing die like abrasives, which will quickly wear and scratch the surface of the wire.
(5) The mold is not smooth or the lubricating oil contains metal chips and impurities, causing the mold to wear. Poor smoothness will cause the surface temperature of the die hole to rise too fast during wire drawing, and the diamond grains will fall off, causing damage to the die. When the lubricating oil is not clean, especially contains metal chips that fall off during drawing, it can easily scratch the surface of the mold and the wire.
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