Large Axial Forgings Convex Cone Anvil Pull Long Study

Heavy forgings are key components in mechanical equipments, theirmicrostructure and properties will directly affect the safety of equipments.Drawing which is one of the main process of shaft forging has a crucial role onthe performance of forging workpiece. But drawing methods currently existforging faults such as uneven deformation, anisotropic of material properties etc.This paper mainly focuses on the research of heavy shafts stretching process, todetermine a forgings tooling device and the corresponding drawing processparameters which can make the deformation uniform and improve the transversemechanical propertiesFirstly, convex cone-shaped anvil was design to realize transversedeformation during stretching process. By analyzing with the finite elementnumerical simulation software Deform-3D, to the material30Cr2Ni4MoV,forgings with different parameters including different anvil angle β, differentanvil width ratio, different percent reduction and different feeds were simulated.Through the analysis of simulation results with different process parameters,comparing the stress state and strain distribution of work piece internal, theappropriate parameters were defined for the blank making process: the convexcone-shaped anvil angle is8°, the anvil width ratio is1.0, the percent reductionis11%(turnover by0°-180°-90°) and the feed value is0.8-0.9.Secondly, the main "modified" procedure (upsetting and stretching) of600MW low-pressure rotors’ forging processes were simulated. And thesimulation results using the blank making process and the traditional forgingprocess for the rotors were compared. The results show that, comparing with theupsetting-drawing once, effective strain of the workpiece forged by blankmaking process is larger. But it’s few smaller then the workpiece forged byupsetting-drawing twice.At the end, the scaling physical trials of upsetting-drawing process and newblank making process were done. Same workpieces were forged with the WHFdrawing method and the new blank making process. After being forged, specimens for tensile and impact test were made at the same position along theaxis and the transverse direction to do tensile and impact test. Comparing theresults of the test,to the mechanical properties of the material changes betweentwo processes after forging. And sampling in the center and the surface of theforgings to analyze the grain size after forging.Therefore, producing heavy shaft forging with convex cone stretchingprocess presented in this paper, is propitious to homogenize the grains andimprove the Transverse mechanical properties. The research work of this paper,for the large shaft parts manufacturing to provide the theory basis, to improvethe level of our country large-scale forging technology has a positivesignificance.