Effect of elements on hydrogen pickup and corrosion behavior of ZrFeCr alloys in 500 °C steam

The influence of Fe and Cr alloying additions on the corrosion resistance and hydrogen pickup behavior of ZrFeCr alloys was studied by simulated corrosion tests and scanning electron microscopy. The results showed that the best corrosion resistance ZrFeCr alloys had the compositions ZrFe0.4Cr1.0. And this alloy has the least hydrogen uptake amounts after corrosion at 500 °C and 10.3 Mpa. Fitting of the weight gain curves for the protective oxide alloys in the region of protective behavior showed nearly cubic behavior for the most protective alloys. The number of precipitates and the amount of hydrogen pickup in the Zr alloy play an important role in the corrosion resistance behavior at steam temperature of 500 °C. The ZrFe0.4Cr1.0 has more fine laves Zr(Fe,Cr)2 precipitate in matrix and has better corrosion resistance. The ZrFe0.2Cr0.1 has little precipitate, the largest hydrogen uptake amounts and has the worst corrosion resistance.