Effect of the Stressed State on the Phase Transformations in Zirconium-Based Alloys

The crystallographic aspects of the phase transformations in zirconium alloys under compressive stresses are studied, and the changes in the sizes of cladding tubes, rods, and rings made of E110opt and E125 alloys at compressive stresses and without them are determined. The temperature of the onset of the phase transformation on heating is found to shift toward low temperatures under a load applied to a cladding tube ring in the diametral direction, and a noticeable strain leading to the appearance of ellipticity of the rings are detected. Some of the versions of the Burgers orientation relationship are operative during the reverse beta-alpha phase transformation under compressive stresses, which manifests itself in the suppression of growth of texture maxima in the applied load direction during cooling. Deformation is shown to be accelerated on heating in the two-phase alpha + beta region under compressive stresses, and the parameters of high-temperature creep are calculated using the temperature dependences of the strain.