Abstract: N36 zirconium alloy specimens were treated in different ways at 1 020 °C/20 min WQ + C.R. (cold rolling) + 580 °C/50 h AC， 820 °C/2 h AC+580 °C/50 h AC, 820 °C/2 h AC+C.R.+580 °C/50 h AC, and 700 °C/4 h AC+C.R.+580 °C/50 h AC, respectively. Their microstructures were examined by transmission electron microscopy (TEM). The corrosion and hydrogen uptake behaviors of these specimens were investigated after autoclave tests in superheated steam at 400 °C/10.3 MPa. Results show that the corrosion resistance of the specimen treated at 1 020 °C/20 min WQ+C.R. (cold rolling)+580 °C/50 h AC is the best among them. The reason is that such treatment makes the second phase particles fine and dispersed in αZr matrix. The corrosion resistance of the specimen treated at 820 °C/2 h AC+580 °C/50 h AC was the worst due to the presence of coarse second phase particles. The corrosion resistance of these specimens treated at 820 °C/2 h AC+C.R.+580 °C/50 h AC and 〖JP2〗700 °C/4 h AC+C.R.+580 °C/50 h AC is in between. Heat treatments have less influence on hydrogen uptake of N36 than that of Zr4. This may be the reason that the second phase particles in N36 alloy is less reactive with hydrogen than that of Zr(Fe,Cr)2 SPPs in Zr4.

Key words: corrosion resistance, hydrogen uptake, second phase particles, zirconium alloy