Annealing effect of hydrogen or argon atmosphere on corrosion resistance of CuAl dilute alloys at high temperature

The annealing effect of H2 or Ar atmosphere on corrosion resistance (CR) of CuAl alloys with 0.2 wt.% Al (CuAl0.2) was examined through oxidation at 973 K in 0.1 MPa O2. For annealing at low temperature of 873 K, Ar atmosphere is more effective for improving CR of CuAl0.2. In the case of higher temperature annealing, the highest CR of CuAl0.2 is observed under H2 atmosphere at 1173 K with slow cooling. Analysis shows that the protection ability of the Al2O3 surface layer formed during annealing is dependent on the partial O2 pressure remnant in H2 or Ar atmosphere.