Effect of low hydrogenation on the low-cycle fatigue of zirconium alloy

The comparative low-cycle fatigue tests of small-sized flat E110 zirconium alloy samples (hydrogenated and non-hydrogenated) at room temperature using a dynamic mechanical analyzer have been carried out. It is shown that the presence of hydrogen in E110 alloy with a mass fraction up to 0.02% has a positive effect on the fatigue resistance of samples oriented transversely to the rolling direction and does not affect the fatigue resistance of the samples oriented along the rolling direction. The mechanisms of the fatigue crack propagation in hydrogenated samples with different orientation of hydrides are proposed.