Residual stresses in oxide layers and corrosion kinetics of Zr-based alloys

摘要

The results of X-ray diffraction analysis of macroscopic stresses in oxide layers and substrate of zirconium alloys are presented in this contribution. Stresses were studied on the tubular specimens of two types of alloys: low tin Zircaloy-4 (Zry-4 W) and standard Zircaloy-4 (Zry-4S) which were simultaneously exposed for various time in water with 43 ppm O_2 at 360 °C. Microstructure characteristics (crystallite size and lattice strains) were evaluated for oxide layers and the metal underlying. Only compressive stresses (up to 1,1 GPa) were determined in the oxide layers of samples investigated. Only tensile stresses (up to 250 MPa) were determined in metal underlying for all the specimens investigated. The relation between the stress development in oxide layers and kinetics of the alloys investigated was outlined.