In a recent paper,1 Das and Parrish have described the introduction of hydrogen into steel from lubricants during machining. In this paper, we present results from a similar study of a zirconium alloy, Zr-2.5 Wt% Nb. Although it is important in machining some zirconium alloy components that the hydrogen pickup be as low as possible, the work reported here arose during the preparation of specimens for hydrogen analysis.
Much of the hydrogen analysis done for the nuclear industry has been on fuel sheathing. Samples from the ≈ 0.5 mm thick sheathing can be obtained by shearing, with no danger of hydrogen contamination. Pressure tubes in power reactors have wall thicknesses typically 4 mm and some machining operation is required to obtain an analytical sample.
The material from which samples for hydrogen analysis were taken was 4 mm thick, cold worked, Zr-2.5 Wt% Nb tube, which from analyses of samples...
