Study On Forming Of Super Large Plate Based On Cylinder Mandrel Reaming And Flattening Technology

With the large-scale nuclear power and petrochemical industries developing rapidly, such heavy forgings as large flat forgings and other working components have been demanded increasingly. These forgings are often used in high-stress conditions, therefore they must not only meet the dimensional accuracy requirements, but need to accord with the high standard of mechanical performance during the producing process. Recently, large ingots are generally used to produce large forgings. During the molding process, appropriate deformation is needed to transfer the composition of the ingots cast into dense state microstructure of the forgings and make a reasonable distribution of metal flow lines. Restricted by the size and weight of heavy forgings, the traditional equipments and techniques can not complete the manufacture of such large-scale forgings, so it needs to formulate a reasonable plan to achieve the purpose. For instance, the key supporting components of 800MN hydraulic press apparatus——"C" plate forgings, researched by China National Erzhong Group Co. are in large size and in a complex shape. It is hardly to complete the molding processing under the ordinary programs.Under the conditions of the existing equipment, "reaming—flattening" process is a unique producing method to manufacture the large flat forgings. By mandrel reaming method, hollow billet thickness is reduced to the certain thickness of cylindrical forging, then after longitudinal split and flattening process, flat forging with the ideal size is completed. In this paper, "reaming—flattening" process of large plate has been studied, and the main contents are as follows:①Analyze the processing program of "C" plate under the current conditions of production.②Usually plane strain hypothesis is used on mandrel reaming analysis of large cylinder forging. This paper, combining of physical modeling and numerical simulation studies the adaptability of the hypothesis.③Formulate the reaming process of cylinder forgings, which is needed to product "C" plate, and analyzed the various factors affecting the deformation.④Use numerical simulation to analyze the mandrel reaming process of large cylindrical forging to determine reasonable parameters. ⑤Analyze the vertical split method of cylindrical forging and the flattening process of arc-shaped forging after the cylinder split.After the research of this paper, a better understanding of the "reaming—flattening" method of large flat forgings will be reached, and the relevant conclusion can be directly used to guide the manufacture of large forgings.