EFFECT OF CHROMIUM COATINGS ON THE MECHANICAL PROPERTIES OF Zr1Nb FUEL CLADDINGS IN LONGITUDINAL AND TRANSVERSE DIRECTIONS

This study was aimed at investigating the chromium coating effect on the mechanical properties of Zr1Nb fuel claddings in the case of a tensile fracture in longitudinal and transverse directions at temperatures of 20 and 350 degrees C. Tests were carried out using the samples of a similar shape, namely, with an equal test portion length that is important for comparison of results. The obtained results have shown that at a test temperature of 20 degrees C the mechanical properties of initial samples are higher in the longitudinal direction than in the transverse direction. The ductility is slightly higher at T = 350 degrees C in the longitudinal direction, and sigma(0.2) and sigma(B) are practically equal. The preliminary deformation of ring samples increases their ductility from 23 to 34% independently on the test temperature. Deposition of the chromium coatings on the samples leads to the slight increase of mechanical properties in the transverse direction and decrease of sigma(0.2) with unchanged sigma(B) and delta% in the longitudinal direction at the room test temperature, and at 350 degrees C it practically do not change the properties of coated samples in both the directions except the ring sample ductility decrease.