Cemented carbide die materials need to have four major properties：
1. with high toughness: tungsten carbide die in the extrusion process to simultaneously withstand the great extrusion pressure, bending stress, impact and other complex loads. Therefore, the requirements of the material selected, after heat treatment, should have high toughness. Therefore, the die material should have good hardenability, so as to ensure that the die can be hardened and uniform organization. Large carbide and serious deflection, fiber directional and non-metallic inclusions and other internal defects, will make the mold toughness is reduced, or in the load caused by stress concentration, resulting in early damage to the mold.
2. Good wear resistance: the die should have high wear resistance, in order to ensure the normal service life, the production of large quantities of qualified extrusions. Generally speaking, the hardness of steel and wear resistance under certain conditions is proportional. Therefore, the die material should not only have sufficient hardenability, but also have high hardenability. But in addition to hardness, determine the wear resistance of steel and heat treatment of the matrix organization of the coarse, composition, excess and mouth fire precipitation carbide phase how much, size, type, dispersion and red hardness, etc.. Such as high-speed steel and low-alloy tool steel, although the same hardness value after heat treatment, the actual use, the former wear resistance is much higher, and contains more than 80% of WC carbide, its wear resistance than steel tens of times higher. Therefore, in the mass production of extrusion, in order to get a long service life of the die, still more high price, complex process of high-speed steel, carbide for the die material.
3. Sufficient thermal stability: When continuous production, the temperature rise of the mold sometimes reaches or exceeds 200 ℃, which is 160 ~ 180 ℃ for tempering temperature mold material, will make the strength, hardness decline, so the temperature rise for higher mold materials, should have good tempering stability.
4. good technology: cold extrusion die manufacturing cycle is long, complex process, high precision requirements. Generally are subject to forging, cutting, heat treatment, grinding or other finishing processes. Therefore, only the process is relatively good material, to meet the needs of production.
Post time: Jun-14-2023
