The effect of mechanical characteristics of steels on the residual stress level after pressing in of heat exchanging tubes in steam generator collectors

The effect of pressing in of heat exchanging tube on residual stress level in steam generator collector based on computer simulation results are described. Computer program based on the finite elements method was used to calculate residual stress-strain fields. The program makes it possible to investigate influence of deformation process, separate for tubes and collectors in the presence of a clearance and their contact interaction, taking into account material non-linear rheological properties, damage and crack appearance. The influence of the yield stresses of the tube and collector materials, the ratio of the material yield stress to hydrostatic pressure used for pressing in on residual stress level are shown. The numerical results reveal that residual stresses depend on the used schemes of loading and parameters of pressing in. (author). 8 refs., 2 figs