Microstructure and corrosion behavior of Zr-702 joined by electron beam welding

Zirconium alloy (Zr-702) joints welded by electron beam welding technique were characterized by studying the microstructures and corrosion tests. X-ray diffraction and transmission electron microscope analysis showed that the joints were consisted of α-Zr and β-Zr phases. Small β-Zr blocks were distributed along the edges of lamellar α-Zr in the fusion zone. Analysis of corrosion behavior of the joints showed that the Zr3Fe intermetallic was presented in the base metal strongly affected the corrosion resistance. The heat-affected zone and fusion zone showed better corrosion resistance than that of the base metal.