How to check the quality of ring forging?

The choice of deformation mode can directly affect the plastic flow and stress state of the deformed body in the shape cavity. For example, the more compressive stress the billet of tongxin precision Forging Company is subjected to during deformation, the better its plasticity is. Therefore, some measures can be taken to increase the three-way compressive stress state and prevent the billet from cracking for materials with low plasticity during plastic deformation. For example, when upsetting, the movable ring or covering can be used for forming, and when drawing, the anvil can be used for drawing, which can improve the drawing efficiency.

To improve the uniformity of material composition and structure, the chemical composition and structure properties of alloy ingot are not uniform, the high temperature diffusion annealing can be carried out before plastic processing, so that the structure and composition in the ingot are uniform, and the plasticity of the material can be improved. Due to the long production cycle and high cost of high temperature homogenization treatment, it can be replaced by appropriately extending the heat holding time when forging is heated. Its disadvantage is to reduce the productivity, and attention should be paid to avoid coarse grain size.

Reduce the degree of non-uniform deformation, which will cause additional stress, resulting in the reduction of billet plasticity, and promote the generation of cracks. The measures commonly used to reduce the uneven deformation are: reasonable operation specifications, good lubrication, appropriate mold shape, etc., can reduce the uneven deformation. If the feeding amount is too small, the forging of the center of the blank may be impenetrable, resulting in additional stress, and the core crack may be formed in serious cases. In the process of upsetting, it is helpful to reduce the drum shape of blank and prevent the surface crack.

Ductile fracture of metals generally refers to the internal microdefects of metal materials, such as microcracks and microvoids, which will nucleate, grow, converge and lead to the gradual deterioration of materials after severe plastic deformation under the action of external loads. When a certain degree of strain is reached, macroscopic fracture of materials will occur. The main characteristics are obvious macroscopic plastic deformation, such as excessive bulging of the container, excessive elongation or bending of the forgings, etc., and the fracture size has a great change compared with the original size.