Simulation Study On Forming Process Of Steam Generator Conical Cylinder Forgings

Conical cylinder forgings in the steam generator transition section are special-shaped forgings that are difficult to form in large-scale nuclear power forgings,and their product performance directly affects the operating state of nuclear power equipment.In this paper,the hollow steel ingot is used as the original blank,and the forging principle of the hollow stepped blank reaming forming method is used as the basis for calculating the outer shape of the target rectangular barrel forging intermediate,and then the forging process of the target conical cylinder is developed.The DEFORM-3D software simulates the finite element model of each forging process of the conical cylinder.This paper focuses on the influence of the change of process parameters in the forging process of the target cone cylinder on the change of the outer dimensions of the blank and the distribution of stress and strain field in the internal deformation zone,in order to obtain the forging of the billet with good deformation quality in each forming process.The range of process parameters and provide a theoretical basis for the actual production process.In the research of the blanking process of the hollow cylindrical blank,the deformation defects of the blanks of different sizes are analyzed,and the curve of the size range of the blanks to avoid the defects of the inner wall is drawn,which provides a reference for the selection of the initial hollow cylindrical blank.In the research process of mandrel drawing and forming hollow step blank,the reasonable range of process parameters such as feed rate,single anvil underarm rate and wrong anvil angle in mandrel drawing process is explored,under reasonable forging process parameter deformation conditions.The blank can obtain sufficient plastic deformation,improve the internal quality,and avoid serious free end face and inner hole distortion defects.In addition,considering the various feature sizes of the hollow step blank and the reasonable forging process parameters of the mandrel drawing process,a reasonable forging step of the hollow step blank is developed,and the hollow step blank with better deformation quality is forged.In the research process of the partial mandrel reaming forming cone cylinder,the reasonable core of the local mandrel reaming process is explored mainly from the aspects of allowable variation of blank dimensions,the rationality of internal field distribution and forging efficiency.The range of forging process parameters such as shaft diameter,single anvil undercut rate,feed rate,mandrel angle,etc.Under reasonable process parameter deformation conditions,the blank can obtain good deformation quality and can also form target forgings under high forging efficiency.Finally,combined with the reasonable range of forging process parameters and the various feature sizes of the hollow step blank,the progressive forging step of the tapered side of the partial mandrel reaming cylinder is designed,and finally,a tapered cylinder with uniform wall thickness and good shape is finally formed.