中国有色金属学报(英文版)
Transactions of Nonferrous Metals Society of China
| Vol. 30 No. 3 March 2020 |
（1. Institute of Materials, Shanghai University, Shanghai 200072, China;
2. Science and Technology on Reactor Fuel and Materials Laboratory, Nuclear Power Institute of China, Chengdu 610213, China）
Abstract:To better understand the role of dissolved oxygen (DO) in affecting corrosion behavior of zirconium alloys, the Zr-0.85Sn-0.16Nb-0.37Fe-0.18Cr (wt.%) alloy was corroded in super-heated steam at 500 °C and 10.3 MPa under 1×10-6 DO and deaeration conditions. The microstructure of the alloy and oxide films was investigated by SEM, TEM, EDS and EBSD. Results show that the corrosion is aggravated under 1×10-6 DO. Compared with the deaeration condition, the oxide film is looser, and has more micro-cracks and more uneven inner surface under DO condition. For the oxide film forming under deaeration condition, the selected area diffraction (SAED) spots of planes (002)m, and (101)t are strong, while those of the (001)m and are weak. However, for the oxide film forming under DO condition, the SAED spots of planes (111)m, (200)m and (101)t are strong, while those of the (100)m and (110)m are weak. The higher DO content in super-heated steam accelerates the growth of oxide films, thus decreasing the corrosion resistance of zirconium alloys.
Key words: zirconium alloy; dissolved oxygen; corrosion; microstructure; oxide film; super-heated steam
