1, the forging has defects such as shrinkage cavity and segregation. Reasonable upsetting process can weld internal defects, reduce segregation and meet technical requirements.

2. Due to the requirement of mechanical properties, the comprehensive mechanical properties of uniaxial forgings with poor tangential properties can be improved by upsetting and drawing for many times. One is the requirement of forging ratio. Different forging ratios have different mechanical properties. Generally speaking, a large forging ratio is beneficial to improve the properties of forgings, and there are also ways to break the as-cast dendritic structure and refine the grains. Due to the shrinkage and porosity of forgings, reasonable upsetting process can weld internal defects and meet the requirements.