Research On 1Cr18Ni9 Stainless Steel Tube Stagger Spinning

Compared with conventional power spinning, stagger spinning has unique advantages. Recently, stagger spinning technology has been widely used in the fields of aerospace, aviation and military industry, etc.However, the factors affecting the tube stagger spinning process are too numerous and too complex; it is time-resuming and uneconomical to determine the technical project by experimentation. The forming rules of stagger spinning have been studied through the finite-element numerical simulation method. Experiments have also performed to verify the validity and the reliability of the simulation results. The research and results are listed as following:According to the factors affecting the tube stagger spinning, the relevant simulation projects have been determined. Based on the analysis software DEFORM-3D of bulk forming, the three dimensional elastoplastic finite element model, which is fit well with the real process of tube stagger spinning has been established to perform the numerical simulation.It reveals the metal flowing rule in stagger backward spinning process and the rule of stress-strain distribution in the wokpiece. The metal in compressed zone flows along the radial, axial and tangential direction, mainly the axial direction. The contact field between the spinning rollers and the billet is in the three-dimensional stress condition, whereas the other field is mainly in the two dimensional compressive and one dimensional tensile stress conditions。Axial strain is mainly a compressive one, whereas tangent or radial strain is mainly a tensile one.The influence law of the variation of technical parameter such as forming angle of the roller, feeding ratio, reducing rate and axial stagger value on the equivalent stress and spinning forces has been analyzed in the paper. It shows that the equivalent stress and spinning forces increase with the increased parameter. An appropriate set of parameters (forming angle of the roller is 30°,feeding ratio is 0.8mm/r, reducing rate is 30%, axial stagger value is 3mm)that have been obtained provide a theoretical evidence for the optimization of the stagger spinning process. The reason, the magnitude and distribution of damage, piling and diametral growth defects during spinning process have been also investigated in this paper. Based on the simulation results, the main factors such as forming angle of the roller, feeding radio and axial stagger value influencing the quality of spun workpiece have been investigated by experiments. It indicates the unreasonable matching relationships of technical parameters will result in the defects such as piling and diametral growth by comparing and analyzing of experimental and simulated results. The experimental research indicates that the simulation results will be helpful to direct the practice production, control and predict the defects effectively in order to produce the spun products with high quality.