Plastic Deformation and Fracture During the Zr1Nb Tube Production

摘要

The deformation of ZrNb alloy tubes involves plastic flow localization in the metal, which is one of the most complex in the theory of material plasticity. The plastic deformation is accompanied by initiation of auto-waves in the body of material. The auto-wave model of plastic deformation was used as a very informative source for getting information to optimize the cold deformation process of zirconium alloy material, in particular for Zrl%Nb alloy cladding tubes. The results of local X-ray measurements of residual stresses were compared with the results of ultrasonic speed measurements in the same tubing material. The correlation between ultrasonic speed and residual stresses has been found and investigations conducted have allowed the improvement of the process of zirconium alloy tube manufacturing. The results obtained were used in developing the optimal processes of cold deformation of tubes made from Zrl%Nb alloy. Those processes provided, together with optimal heat treatment regimes, high cladding tube performances in comparison with those obtained with other well-known manufacturing processes.