Abstract
Zirconium alloys are one of the main cladding materials in pressurized water reactors. Corrosion resistance of zirconium alloy cladding weld is one of the most important factor affecting fuel integrity. CZ zirconium alloys have been recently developed for advanced PWR fuel assemblies which are designed by China General Nuclear Power Group (CGN). There are two kinds of zirconium alloys, designated as CZ1 and CZ2 respectively. CZ1 is Zr-Sn-Nb alloy, and CZ2 is Zr-Nb alloy. In this paper, the autoclave corrosion test of CZ2 zirconium alloy welded specimen was executed. Then, the corrosion resistance of CZ2 zirconium alloy welding specimens was evaluated by analyzing the the appearance, corrosion weight gain and oxide film thickness. The result shows that corrosion resistance trend of combination of CZ2 and CZ2, CZ2 and Zr-4 welding specimens is basically the same under the conditions of 360 °C /18.6 MPa deionized water and 400 °C /10.3 MPa superheated steam. There was no obvious difference due to different hydro-chemistry. The corrosion resistance of CZ2 and Zr-4 welding specimens is better than that of CZ2 and CZ2 welding specimens. Therefore, the use of Zr-4 end plug material can reduce the sensitivity of CZ2 alloy to heat effect and improve the corrosion resistance of CZ2 alloy cladding.
