Investigation of guided external inversion of thin-walled round tube

A new tube inversion method called guided tube inversion(GTI),which is based on traditional axial compression inversion,has been put forward.Computational and experimental studies of the guided external inversion of round tubes are presented.The main features of the deformation and the effects of key parameters on the forming process were discussed.Numerical and experimental results both indicated that the double-walled tubular parts made by the new method have a much higher quality than those made by traditional methods,as long as the proper parameters of the process were utilized.It was found that the die radius r,the inner diameter D of the guiding ring,the velocity V of the guiding system,and the surface friction between tube and guiding ring,play important roles in the inverting process.