Research On Forming Method Of Difficult-to-deform Metal In Hot Power Spinning

Complex chemical composition, high content of alloy elements and deformation resistance are the characteristics of difficult-to-deform metal. Good high temperature strength, good corrosion resistance and oxidation resistance and so on are the prominent characteristics of Ni-based high-temperature alloy, so it is widely used in complex environment such as aerospace, shipbuilding, gas turbine, energy, chemical industry, and the electronics industry, etc. But due to the serious work hardening when processed at room temperature, it presents higher deformation resistance and plastic deformation ability drops rapidly at the same time, its forming becomes more difficult. For the forming process of Haynes 230 cylindrical parts used in combustor, the existing manufacturing methods are very conservative, the commonly used method is welding after the sheet is rolled. In recent years, with the application of hot power spinning forming technology in the materials such as titanium alloy, magnesium alloy forming, the forming process and technology get a rapid development. The plastic deformation ability of difficult-to-deform metal increased significantly due to dynamic recovery and dynamic recrystallization under high temperature and the deformation resistance decrease largely, but its forming limit increases largely, less power and stiffness requirement to equipment when forming, at the same time, the cylindrical parts with compact organization, high dimensional accuracy and high material utilization can be obtained through hot power spinning, and it has presented great advantages in difficult-to-deform metal processing of hot power spinning.This article mainly research on the hot power spinning forming method of difficult-todeform metal Haynes 230 of cylindrical parts. The reasonable forming process of hot power spinning is made. The finite element simulation analysis software of ABAQUS is used to simulate hot power spinning process, the forming quality and microstructure of parts after hot power spinning are analyzed. The main research contents and conclusions in this paper are as follows:First, depending on the size of the tube material, the mechanical properties as well as theoretical knowledge of power spinning, the forming process including reduction ratio, feed rate and spinning temperature is made. the commonly used heating forms includes flame heating and induction heating, choose the high frequency induction heating to heat workpiece after comparing two heating modes from temperature uniformity, heating speed and temperature controlling, temperature controller is used to control the heating temperature. At the same time, mandrel preheating can effectively reduce the heat transferred to mandrel from workpiece, and the workpiece’s temperature distribution will be uniform.Second, according to the theory of spinning forming, considering the influence of temperature, equipments required in forming process are designed. HGQX-LS vertical hot power spinning machine is upgraded and added the thermodetector, temperature controller and the high frequency induction heating equipment, which lays the foundation for hot power spinning experiment.Third, the hot power spinning process is simulated with ABAQUS and use the high temperature material constitutive model. The effects of hot power spinning temperature and feed rate on spinning process are obtained. It provides important reference basis for the subsequent test.Fourth, wall thickness deviation, straightness and ovality of spun parts are analyzed, the machine tool’s concession, the material’s springback and the heat-expansion and cold-contraction lead the loss of accuracy. The surface quality of workpiece has direct influence on spun part. And appropriate feed rate is important to obtain a good surface quality part.Fifth, the strength increase greatly and the work hardening is obvious, which can be obtained through mechanical properties test of spun parts. Analyzed the microstructure of spun parts at different temperature, fibrous tissue can be seen and recrystallization grain size increase with the rise of spinning temperature, the strength of spun parts show a downward trend with the rise of spinning temperature.