750 Kgs 500mm Multipurpose Furnace Super Low Temperature Freezer Liquid Nitrogen

Cemented carbide cold heading dies are often used for cold heading, cold punching and upsetting of metal materials. They bear great impact force during work, the impact frequency is very high, and they have a certain working temperature. The use environment is very harsh, which requires cold The upsetting die has both good impact toughness and a certain degree of wear resistance.

At present, in order to improve the toughness of cold heading molds, alloys with high cobalt content (mass fraction of about 20%) are generally used in production. However, the thermal expansion coefficients of WC and Co are very different, and the inside of the alloy will be lower than that of cobalt during the cooling process. The alloy produces greater tensile stress, which causes the cold heading die to easily crack and fall off during use, and the service life is short. Metal Co has two crystal structures of face-centered cubic cobalt (fcc) and close-packed hexagonal cobalt (hcp). Face-centered cubic cobalt (fcc) has good plasticity, but has low hardness and is easy to deform. The plasticity of close-packed hexagonal cobalt (hcp) Poor, but high hardness and good wear resistance. After sintering, most of the metallic Co in the alloy exists in the form of face-centered cubic cobalt (fcc), especially in low-carbon alloys, and the metallic Co almost completely exists in the form of face-centered cubic cobalt (fcc). In this case, although the toughness of the cemented carbide for cold heading die is good, the wear resistance is insufficient and the overall performance is poor.