Springback and time-dependent springback of 1Cr18Ni9Ti stainless steel tubes under bending

In this paper, the springback and time-dependent springback of 1Cr18Ni9Ti stainless steel tubes subject to bending is explored. Rotary draw bending tests have been carried out and marked time-dependent springback has been observed. A novel model in which time-dependent springback is associated with strain hardening is presented as an attempt to analyze this behavior. Using this model, the formulae of time-dependent springback, time-independent springback and total springback are derived. In addition, finite element analysis has been performed to investigate the stress distribution as well as to calculate the magnitude of springback. Comparison between analytical and experimental results shows good agreement.