There are many precision forging processes currently used in production. According to different forming temperatures, it can be divided into hot precision forging, cold precision forging, warm precision forging, and composite precision forging. Let's introduce them in detail today in turn:
The first is the hot precision forging process: Hot precision forging refers to the precision forging process that is forged above the recrystallization temperature. Because the deformation temperature is high, the material has low deformation resistance and good plasticity during forging, so it is easy to form parts with complicated geometric shapes. Closed die forging is a commonly used process for hot precision forging. Due to mold design, inaccurate blanking, insufficient manufacturing accuracy, etc., closed die forging has a large deformation resistance at the end of forging, which will have harmful effects on the mold and equipment. The problem can be solved by using the principle of shunting and reducing pressure, that is, a shunting and reducing cavity hole of a suitable shape is set at the last filled part of the closed cavity. When the cavity is completely filled, the excess metal of the blank flows out of the shunting cavity hole, which solves the blank The problem that the volume cannot be strictly equal to the cavity volume also reduces the internal pressure of the cavity and increases the service life of the mold.
Next is the warm precision forging process: warm forging is a precision forging technology that heats the metal to a suitable temperature below the recrystallization temperature. It has the advantages of hot forging and cold forging at the same time, avoiding their defects, effectively reducing the load of equipment and molds, improving the plasticity and fluidity of the metal, and without forging and annealing. However, the forging temperature of the warm precision forging process is low, the forging temperature range of the forging is narrow and the forging range is relatively strict. It requires high-precision specialized equipment, and at the same time, it has higher requirements for the mold structure and mold materials.
Finally, the cold precision forging process: the cold precision forging process is a precision forging forming technology that is forged at room temperature. Due to the room temperature forming, avoiding the dimensional error caused by thermal expansion and contraction, the shape and size of the cold precision forged workpiece is easier to control, and the surface of the forging does not produce oxidation and burnout, etc., and has a high surface quality. The forging accuracy of both forging and warm precision forging is lower than that of cold precision forging. In addition, the work hardening effect produced by cold precision forging can significantly improve the strength of cold forged parts. However, during cold forging, the deformation resistance is large, the plasticity of the workpiece is poor, the filling effect is poor, and the requirements for equipment and molds are high, so it is difficult to form parts with complex shapes.
These three are the forging processes commonly used by crane wheel forging parts in the forging plant. Choose different forging methods based on different forgings.