Hydrogen uptake during oxidation of zirconium alloys

By analysing hydrogen uptake data for Zircaloy specimens with the same chemistry, but different thicknesses, it is found that hydrogen uptake rates decrease when TSS in the metal is exceeded. Hydride precipitation is usually uniform in the bulk metal, and could only affect hydrogen uptake if the tendency to precipitate in the bulk is overcome and precipitation occurs at the point of ingress. This requires very high local ingress rates and a very local uptake process (10(-4) of the surface area) to achieve. (C) 1997 Elsevier Science S.A.