Room temperature mechanical properties of electron beam welded zircaloy-4 sheet

Abstract

Resumption of operations at the Transient Reactor Test (TREAT) facility at Idaho National Laboratory was approved in 2014 to meet U.S. Department of Energy Office of Nuclear Energy objectives in transient testing of nuclear fuels. In parallel, the National Nuclear Security Administration, through the Office of Material Management and Minimization, is converting TREAT from its existing highly enriched uranium core to a low-enriched uranium core. This effort entails designing, fabricating, and qualifying a new TREAT low-enriched uranium fuel assembly, while maintaining TREAT's experimental performance capabilities. Zircaloy-4 is being evaluated as TREAT lowenriched uranium assembly material. A preliminary study on the room temperature mechanical properties of asreceived and electron beam welded Zircaloy-4 sheet (1.6 mm) is presented. The sheet was high-vacuum electron beam welded using a three-pass process with varying heat input: (1) tack welding (10.5 J/mm), (2) seams welded (36.7 J/mm), and (3) sealed (15.7 J/mm). As-received and electron beam welded specimens show comparable properties. Zircaloy-4 displays anisotropy between the transverse and longitudinal directions. Tensile properties measured for the transverse direction display higher yield strength, reduction of area, and slightly lower tensile strength and ductility than for the longitudinal (i.e., rolling) direction. Weld and base metal hardness are comparable, while hardness at the heat-affected-zone is slightly higher. Microscopic examinations show distinct microstructure morphology and grain size from weld to base metal. A correlation between welding parameters, mechanical properties, and microstructural features was established for electron beam welded Zircaloy-4 sheet.

Effect of weld parameters on porosity formation in electron beam welded Zircaloy-4 joints: X-ray tomography study

“…3 the mechanical properties of EB-welded Zr-4 sheets and observed porosity in the weld joints [19]. Moreover, this porosity formation greatly affects the mechanical and corrosion properties of weld joints.…”

Study of Microstructure and Performance Evaluation of Zr-Sn-Nb Joints by Electron Beam Welding

“…The study by Jha et al [ 18 ] showed that the hardness of Zr-4 alloy electron beam welded joints is higher than that of the BM. The tensile properties of Zr-4 alloy electron beam welded joints are not inferior to those of the parent material [ 19 ], but the presence of pores in the weld may affect the corrosion performance of the joint [ 20 ]. Bandi et al [ 21 ] demonstrated through Raman spectroscopy that the pores in the Zr-4 electron beam welded joint are mainly hydrogen pores.…”

Weld Growth Mechanism, Microstructure, and Mechanical Properties of Resistance‐Spot‐Welded Joint of R60702 Zirconium‐Alloy Triple Sheets

“…Zirconium (Zr) alloy is widely used in the nuclear and aerospace industries due to its high corrosion resistance, high-temperature stability, excellent mechanical properties, and low thermal neutron absorption cross-section. [1][2][3] In the manufacturing process of these industries, complex structural components often feature overlapping joints composed of multiple layers. Moreover, in critical areas, reinforcing plates are added to ensure manufacturing quality, resulting in a significant number of three-layer or multilayer plate overlap structures.…”