Research On Residual Stress Of Precision Turning Of Weak Rigid Thin-walled Parts Of Pure Iron

Pure iron has the characteristics of soft texture,high plasticity,high toughness and excellent electromagnetic properties.It is widely used in manufacturing precision military components of the national defense industry.The pure iron thin-walled spherical shell is the key component of the detonation experiment,and the contour error of the spherical shell has an important influence on the experimental results.After optimizing the deformation factors such as cutting force and clamping force,the cutting residual stress has become a bottleneck factor of further improving the manufacture precision of weak rigid spherical shells.In this paper,the cutting residual stress of pure iron thin-walled spherical shells should be researched by turning test,numerical simulation and mathematical modeling,and the main research contents and results are as follows:(1)The turning test and annealing test of pure iron are carried out,and the residual stress distribution of turning is measured by X-ray diffraction method.The effects of grain size,cutting parameters and annealing temperature on the turning residual stress distribution characteristics of pure iron are mastered.(2)The Power-Law material constitutive model parameters of 7-8 grade grain size pure iron were obtained through tests.In order to obtain data such as cutting force,machined surface temperature,and turning residual stress,the precision turning simulation and test are carried out.Based on mechanical and thermal loads,the mathematical model of turning residual stress on the pure iron parts surface has been constructed.(3)The finite element simulation model of pure iron thin-walled spherical shell is established,and residual stress corresponding to current cutting parameters is introduced by using the residual stress mapping algorithm.The spatial distribution law of the deformation of thin-walled spherical shell parts has been obtained,which provides a reference for process optimization.