Tungsten steel dry pressing molds should have high wear resistance, to ensure normal service life, and to produce large quantities of qualified kneading parts. In general, the hardness and wear resistance of steel are directly proportional to the conditions. Therefore, it is required that the mold material not only has satisfactory hardenability, but also has high hardenability.
However, in addition to the hardness, the wear resistance of the steel is also determined by the thickness of the matrix after heat treatment, the composition, the excess and the amount of carbide phase, the size, the dispersion, and the red hardness. For example, high-speed steel and low-alloy tool steel, although having the same hardness value after heat treatment, the wear resistance of the former is much higher in actual use, while the hard alloy containing more than 80% WC has higher wear resistance than steel. ten times. Therefore, in the large-scale kneading production, in order to obtain the long service life of the mold, high-speed steel and hard alloys with high price and complicated process are still used as mold data.
The strain caused by the adhesion of the surface of the workpiece to the surface of the convex and concave molds of the mold is also a common condition in production which is not easy to solve. Solving the problem of strain on tungsten steel dry pressing die and workpiece forming process should be based on the basic principle of reducing adhesive wear, and changing the nature of contact pair as the starting point.