(1) The drawing surface shrinkage is too large, causing the drawing die to crack or break. 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 generated during wire drawing can enhance the microcrystalline structure of the mold, but when the drawing surface shrinkage is too large, it cannot be lubricated in time and the temperature rise is too high, which will cause the mold It shows that when part of the material is removed, the stress on the microcrystalline structure is greatly increased, making it more prone to cracks or breakage.
(2) The drawing axis of the wire rod is asymmetrical with the center line of the die hole, resulting in uneven stress on the wire rod and the wire drawing die, and the impact generated by mechanical vibration will also cause high stress peaks on the wire rod and the drawing wire die. Will accelerate the wear of the mold.
(3) Factors such as uneven wire hardness caused by uneven annealing are likely to cause premature fatigue damage to the diamond wire drawing die, forming annular grooves, and aggravating 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 cause the wire drawing die hole to wear quickly and scratch the wire surface like abrasives.
(5) Poor lubrication or the lubricating oil contains metal debris and impurities that cause mold wear. Poor lubrication will cause the surface temperature of the die hole to rise too fast during wire drawing, and the diamond grains will fall off, resulting in damage to the die. When the lubricating oil is not clean, especially when it contains metal chips that fall off during drawing, it is very easy to scratch the surface of the mold and the wire.
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