Hydride embrittlement in ZIRCALOY-4 plate; Part 1: Influence of microstructure on the hydride embrittlement in ZIRCALOY-4 at 20[degree]C and 350[degree]C

Journal Article · Wed Jun 01 00:00:00 EDT 1994 · Metallurgical Transactions, A (Physical Metallurgy and Materials Science); (United States)

DOI:https://doi.org/10.1007/BF02652293· OSTI ID:7175328

Bai, J B; Prioul, C; Francois, D ^[1]

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1. Ecole Centrale Paris, Chatenay-Malabry (France)

The hydride embrittlement in ZIRCALOY-4 was studied at room temperature and 350 C. Sheet tensile specimens of two fabrication routes in the stress-relieved, recrystallized, and [beta]-treated states were hydrided with or without tensile stress. It was found generally that the effect on strength of increasing hydrogen content was not important. However, for the tensile tests at room temperature, there is a ductile-brittle transition when the hydrogen content is higher than a certain threshold. The prior thermomechanical treatment shifts this transition considerably. In situ scanning electron microscopy (SEM) tests, fractography, and fracture profile observations were carried out to determine the fracture micromechanisms and the microscopic processes. At 20 C, the fracture surfaces are characterized by voids and secondary cracks for low and medium hydrogen contents and by intergranular cracks and decohesion through the continuous hydride network for high hydrogen contents. This phenomenon disappears at 350 C, and the hydrogen seems to exert no more influence on the fracture micromechanism even for very high hydrogen contents (up to 1,500 wt ppm). A full-coverage model is proposed to estimate the critical hydrogen content that makes ZIRCALOY-4 totally brittle. The effect of microstructure on hydride embrittlement in different metallurgical states is thus explained according to the modeling. Special attention is devoted to relating the micromechanisms and the modeling in order to propose the possible measures needed to limit the hydride embrittlement effect.

• OSTI ID: 7175328
• Journal Information: Metallurgical Transactions, A (Physical Metallurgy and Materials Science); (United States), Vol. 25:6; ISSN 0360-2133
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ZIRCALOY 4
HYDROGEN EMBRITTLEMENT
MICROSTRUCTURE
EXPERIMENTAL DATA
FRACTURE PROPERTIES
MATHEMATICAL MODELS
REACTOR CORES
REACTOR MATERIALS
THEORETICAL DATA
ALLOY-ZR98SN-4
ALLOYS
CHROMIUM ADDITIONS
CHROMIUM ALLOYS
CORROSION RESISTANT ALLOYS
DATA
EMBRITTLEMENT
HEAT RESISTANT MATERIALS
HEAT RESISTING ALLOYS
INFORMATION
IRON ADDITIONS
IRON ALLOYS
MATERIALS
MECHANICAL PROPERTIES
NUMERICAL DATA
REACTOR COMPONENTS
TIN ALLOYS
ZIRCALOY
ZIRCONIUM ALLOYS
ZIRCONIUM BASE ALLOYS
360103* - Metals & Alloys- Mechanical Properties
360102 - Metals & Alloys- Structure & Phase Studies