Basic knowledge of forgings

    Brief Introduction to Forging Factory: Basic Knowledge of Forgings
    1. When considering the forging temperature, it is necessary to consider the temperature drop during the contact process between the blank and the mold, and preheat the mold.
    2. For alloys with high degree of difficulty in deformation, slow deformation should be used as much as possible, and the deformation amount of each stroke of each hammer or press should be controlled, generally around 20%. For speed sensitive materials, the selection of deformation speed should also consider temperature effects.
    3. The plasticity of closed die forging is better than that of open die forging, while open die forging is better than free forging. In the free forging process, the elongation of the anvil and the upsetting with the ring are more able to exert the plasticity of the metal than the elongation of the flat anvil and the upsetting without the ring.
    4. When drawing with low plasticity, attention should be paid to selecting an appropriate feed ratio. If the feed ratio is too small, deformation will be concentrated in the upper and lower parts, and the center will not be fully forged, resulting in tensile stress along the axial direction, leading to the generation of internal transverse cracks. When upsetting, soft liners are commonly used for upsetting or stacking (used for forging thin cake shaped parts) to improve the unevenness of deformation and prevent surface cracks.
    5. When considering the forging process, especially the final heat forging, it should be avoided as much as possible to perform at a critical deformation level to avoid obtaining coarse grain structure. Specifically, at high temperatures, metals have good plasticity and low deformation resistance, and larger deformation amounts far greater than the critical deformation degree should be used for forging; During low-temperature correction, small deformations below the critical deformation level are used for local trimming.