Hydrogenation Behavior of Cr-Coated Resistance Upset Welds of E110 Zirconium Alloy

Abstract

The hydrogenation behavior of Cr-coated resistance upset welds (RUW) of E110 zirconium alloy was investigated at 360, 450 and 900 °C and a hydrogen pressure of 2 bar. The deposition of Cr coating, via magnetron sputtering, can decrease the hydrogen absorption rate of an RUW Zr alloy. The activation energy for the hydrogen absorption of Cr-coated specimens (84 kJ/mol) is higher in comparison with uncoated ones (71 kJ/mol), which indicates the deceleration of the hydriding of welded Zr alloys in the case of Cr coating deposition. A Cr coating can limit the formation of radially oriented hydrides and the hardening of RUW specimens at 360 and 450 °C. No significant difference in the hydrogen absorption rate was found at 900 °C. The application of Cr coating deposition to protect resistance-upset-welded Zr alloys in a hydrogen atmosphere is discussed.