Research On Spinnability In Shear-deep Drawing Composite Spinning For Conical-cylindrical Part Of Ni-based Superalloy

Ni-based superalloy has been used as the key material for hot end components of aeroengine,and gas turbine because of its good high temperature strength and anti-oxidation corrosion performance.Ni-based superalloy conical-cylindrical parts are a kind of basic components widely used in aeroengine and gas turbine combustor.Shear spinning and deep drawing spinning are the most effective ways to form conical-cylindrical parts respectively.Shear-deep drawing composite spinning is one of the most effective precise plastic forming methods to prepare Ni-based superalloy conical-cylindrical parts.Spinnability is the theoretical basis to judge whether the material can be successfully spun.Because of the significant work hardening effect of Ni-based superalloy and the heredity of plastic deformation between different processes during composite spinning,the wrinkling,cracking and other defects during forming will be directly affected,which makes the quantitative characterization of spinnability more difficult.At present,there is no report on the spinnability of composite spinning.Therefore,the research on Spinnability of shear-deep drawing composite spinning is the theoretical basis and key scientific problem for controlling forming defects and realizing accurate spinning of such complex components.In this paper,the Haynes230 conical-cylindrical part of Ni-based superalloy is taken as the research object.According to the structural and material characteristics of the parts,the method of composite spinning forming of the conical-cylindrical parts parts of Ni-based superalloy is determined and the research scheme of the spinability of the composite spinning forming is proposed.In the light of the characteristics of shearing spinning and deep drawing spinning,the range of forming parameters is selected reasonably,and the composite spinning tooling die is designed,which lays the foundation for the subsequent research on spinability.According to the proposed method of composite spinning,the finite element model of shear-deep drawing composite spinning of conical-cylindrical parts is established by ABAQUS software.The distribution and variation of stress-strain,wall thickness and ductile damage are analyzed.The results show that the distribution of equivalent strain and ductile damage is the same in the process of shear spinning of cone shaped parts,and the maximum value is reached at the fillet.In the process of single deep drawing,the maximum value of equal effect change and toughness damage occurs at the mouth and fillet of the spinning part.The three-way strain is distributed uniformly in the circular direction,but there is obvious difference in the bus direction.The fillet and the barrel section mainly bear the thick tensile stress and the bus direction pressure stress,and the fillet should be changed greatly;the mouth mainly bears the tangential pressure stress.The stress-strain and toughness damage are larger than that of 60° and 45° with half cone angle.The thickness of the wall at the corner of the conical section and the cylinder section is more serious,and the mouth gradually increases.Based on the deformation characteristics of materials during shearing and deep drawing spinning,the characterization method of spinnability is proposed by taking the deformation degree of composite spinning as the evaluation index of spinnability.Through the combination of finite element simulation and spinning test,the composite spinning forming conditions of different semi cone angle conical-cylindrical parts were analyzed,and the spinnability characterization curve and forming limit diagram was constructed.The results show that the quantitative characterization curve of the composite spinning can be realized by using the semi cone angle of the shear spinning as the horizontal coordinate and the ultimate spinning coefficient of the deep drawing spinning as the longitudinal coordinate.The forming limit diagram can effectively determine the strain state of the safety zone of composite spinning.The ultimate drawing coefficients of the composite forming of conical tube shaped parts are between the interval(0.734,0.741),(0.702,0.708)and(0.625,0.645)respectively when the half cone angle is 45 °,60 ° and 90 °.The smaller the angle of the half cone is,the more wrinkle and fracture defects are produced during the composite spinning,and the spinnability decreases.On the basis of the method of combining finite element simulation and forming experiment,the influence of different forming parameters on the spinnability of composite spinning forming is studied.The results show that the ability of anti wrinkle and fracture defects of the spinning parts decreases with the reduction of blank thickness,and the spinnability of the spinning parts becomes worse.Compared with the standard circular arc spinning wheel,the spinning ability of the composite spinning can be improved to some extent by using the compound surface spinning wheel.With the increase of feed ratio of the spinning wheel,the toughness damage decreases to some extent,but the excessive feed ratio will lead to wrinkle defects at the mouth of the spinning parts.