Study on cross-section distortion behaviors for tube bending at varying geometry parameters

Abstract

Tube bending is often plagued by the critical forming defect of cross-section distortion, which increases flow resistance, affects the strength and stiffness of bent-tube, and thus directly influences the usage performance of bent-tube components. To achieve accurate tube bending forming, the distortion behaviors for cross-section during tube bending should be clarified. A finite element (FE) model accounting for the change in elastic modulus was employed for addressing the distortion behaviors of the cross-section for high strength 0Cr21Ni6Mn9N (0Cr21Ni6Mn9N-HS) tube in NC rotary draw bending at varying geometry parameters. The findings indicate that accounting for the change in elastic modulus can aggrandize the distortion ratio of the cross-section, but has no significant impact on the distortion behaviors for the cross-section. The cross-section ovality behaviors of the 0Cr21Ni6Mn9N-HS tube at various geometry parameters for NC rotary draw bending have been clarified, and the ranges of sound parameters have been determined.