Fatigue Crack Propagation Behavior of Zirconium in Boiling Nitric Acid Solution

摘要

For long term durability evaluation of thereprocessing facility equipment made of zirconium, the fatiguecrack propagation behavior of zirconium in heat affected zone(HAZ), weld metal (DEPO), and base metal (BASE) wasinvestigated. Fatigue crack was propagated in room temperatureatmosphere and in the boiling nitric acid solution. The crackpropagation behavior of zirconium was evaluated by themeasurement of crack propagation rate and the fracture surfaceanalysis. The fatigue crack propagation was accelerated in theboiling nitric acid solution. Moreover the fracture surface causedin the boiling nitric acid solution was fluted one. It was guessedthat acceleration factor of the fatigue crack propagation was thestress corrosion cracking (SCC). Crack sensitivity in the boilingnitric acid environment of welded joint (HAZ and DEPO) andBASE was almost the same.