Hardness and microstructural studies of electron beam welded joints of Zircaloy-4 and stainless steel

Electron beam welded joints between Zircaloy-4 and stainless steel 304L are investigated due to their importance in the nuclear industry. The molten and heat affected zones (HAZs) are found to be free of defects. Diffusion of Fe, Cr and Ni is observed in Zircaloy-4 near the molten zone and of Zr and Sn in the stainless steel. A rod-shaped intermetallic compound Zr(Cr,Fe)2 and eutectic phases ZrCr2–liquid (Zr,Fe) and Zr2Fe–Zr2Ni are present in the molten zone. The hardness of the molten zone, containing Zr(Cr,Fe)2, is much higher than the rest of the molten zone and the HAZs.