Study on the Corrosion Resistance of Zr–1Nb–xM (M = S, Cu, Ge, Bi) Alloys

Abstract

Different contents of S, Cu, Ge and Bi were added respectively to a Zr–1Nb alloy to prepare Zr–1Nb–xM alloys. The corrosion behavior of Zr–1Nb–xS(x = 0–61, μg/g), Zr–1Nb–xCu(x = 0–0.50, wt%), Zr–1Nb–xGe(x = 0–0.20, wt%) and Zr–1Nb–xBi(x = 0–0.30, wt%) was investigated in deionized water at 360 °C/18.6 MPa, in superheated steam at 400 °C/10.3 MPa or at 500 °C/10.3 MPa. Results show that the corrosion resistance of Zr–1Nb alloy is all improved by adding suitable contents of S, Cu, Ge or Bi in different corrosion conditions. The maximum contents of M dissolved in α-Zr of Zr–1Nb–xM alloys are not less than 61 μg/g for S, about 0.20 % for Cu, 0.05–0.10 % for Ge and not less than 0.30 % for Bi. Combined the corrosion results with the microstructures of the alloys, it can be concluded that the S, Cu, Ge and Bi dissolved in α-Zr matrix play an important role in improving the corrosion resistance of Zr–1Nb alloy.