Therefore, in order to let everyone know more about the relevant knowledge of large forgings, the following is mainly for us to learn the mechanical properties of forging and comparing large forgings. One of the most important factors affecting the quality of forgings is the microstructure and mechanical properties of large forgings.
Forging ratio is a representation of the degree of metal deformation during the forging process. The higher the forging ratio, the higher the deformation degree of the forging. The deformation degree is directly related to the final mixed size of the material, the degree of fragmentation of the eutectic carbon of the material, the direction of fiber flow, and the density of the material after final molding, which has a significant impact on the comprehensive properties of the material.
The distribution of the forging ratio (i.e., the degree of deformation) among different forging ratios is uneven, and is clearly divided into regions of large forging ratio, average forging ratio, and small forging ratio. Experiments on mechanical properties show that under the same heat treatment conditions, plastic deformation at a certain forging ratio can significantly improve the strength and plasticity indexes of rolled steel. When the forging ratio reaches a certain value, the microstructure and properties of large forgings change strongly, with strength but toughness significantly reduced. Under the same strain rate conditions, the greater the forging ratio (i.e., the degree of plastic deformation), the more obvious the dynamic recrystallization in the forging structure. When the forging ratio reaches a certain value, the original grains will be replaced by new recrystallized grains, resulting in a more complete dynamic recrystallization.
Currently, there are three process options that can improve the uniformity of the forging ratio, namely, changing the boundary conditions of the blank and the mold, changing the shape of the blank, and changing the upsetting deformation method. Forging ratio and geometric dimension uniformity can be effectively improved by changing the upsetting deformation of a flat anvil. Therefore, in order to better improve the quality of ring forgings, it is necessary to improve the forging ratio of large forgings.