Anisotropic behavior and rupture of hydrided Zircaloy-4 sheets

Journal Article · Wed Mar 01 04:00:00 EST 2000 · Metallurgical and Materials Transactions. A, Physical Metallurgy and Materials Science

DOI:https://doi.org/10.1007/s11661-000-0010-9· OSTI ID:20023143

Grange, M; Besson, J; Andrieu, E

In a French pressurized water reactor (PWR), most of the structural parts of the fuel assembly consist of zirconium alloys (ZIRCALOY-2). The mechanical behavior of ZIRCALOY-4 sheets is investigated at room temperature. The effect of hydride precipitation on the mechanical behavior and on the rupture mechanism is also studied, in the range from 200 to 1,200 wt ppm hydrogen and for different stress triaxialities. It is shown that the material exhibits a strong anisotropy die to its pronounced texture, and that its mechanical properties depend on the strain rate. Hydride precipitation appears to have no effect on the anisotropy or on the strain-rate sensitivity, in the range from 10{sup {minus}4} to 10{sup {minus}2} s{sup {minus}1}. The main effect of hydrogen is the reduction of the ductility and of crack resistance. The ductile rupture mechanism is studied, focusing on the stage of damage nucleation by hydride fracture. Observations during scanning electron microscopy (SEM) in situ tests show that hydrides allow the transmission of slip, which occurs in ZIRCALOY-4 grains. Hydrides can also deform, together with surrounding zirconium matrix. Damage appears after a plastic-strain yield of about 14 to 25 pct. Fracture occurs first on intergranular hydrides. Fracture of transgranular hydrides is observed only prior to failure, for higher plastic strains.

• Research Organization: Framatome Nuclear Fuel, Lyon (FR)
• OSTI ID: 20023143
• Journal Information: Metallurgical and Materials Transactions. A, Physical Metallurgy and Materials Science, Journal Name: Metallurgical and Materials Transactions. A, Physical Metallurgy and Materials Science Journal Issue: 3 Vol. 31; ISSN 1073-5623; ISSN MMTAEB
• Country of Publication: United States
• Language: English

Related Subjects

21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS
36 MATERIALS SCIENCE
ANISOTROPY
ELECTRON MICROSCOPY
HYDRIDES
MECHANICAL PROPERTIES
PRECIPITATION
PWR TYPE REACTORS
STRAIN RATE
ZIRCALOY 4