(1. 上海大學 材料研究所，上海 200072； 2. 上海大學 微結(jié)構(gòu)重點實驗室，上海 200444； 3. 中廣核研究院有限公司，深圳 518031)
摘 要: 利用靜態(tài)高壓釜腐蝕試驗研究了Zr-Nb-Fe管狀樣品在LiOH溶液(360 ℃, 18.6 MPa, 0.01 mol/L)中的腐蝕行為；利用OM、SEM和TEM觀察了合金和氧化膜的顯微組織和氧化膜的形貌。結(jié)果表明：Zr-Nb-Fe合金中的第二相為體心立方的β-Nb、面心立方和密排六方的Zr(Nb,Fe)2。Zr-Nb-Fe管狀樣品腐蝕150 d時腐蝕增質(zhì)曲線發(fā)生轉(zhuǎn)折，轉(zhuǎn)折后的腐蝕速率顯著加快，氧化膜表面出現(xiàn)包狀凸起，該包狀凸起比片狀樣品的凸起形貌較圓些，其周圍氧化膜明顯變厚且較為疏松。轉(zhuǎn)折后樣品的吸氫量雖有增加，吸氫分數(shù)卻明顯降低，因而氧化膜中包狀凸起的形成與未被鋯合金吸收的氫需要通過氧化膜向外逸出有關(guān)。
關(guān)鍵字: Zr-Nb-Fe合金；LiOH溶液；包狀凸起；吸氫分數(shù)
（1. Institute of Materials, Shanghai University, Shanghai 200072, China; 2. Laboratory for Microstructures, Shanghai University, Shanghai 200444, China; 3. China Nuclear Power Technology Research Institute, Shenzhen 518031, China）
Abstract:The corrosion behavior of Zr-Nb-Fe in lithiated solution(360 ℃, 18.6 MPa, 0.01 mol/L) was investigated by autoclave tests. The microstructure of Zr-Nb-Fe alloy and the morphology of oxide film were observed by OM, SEM and TEM. The results show that the second phase particles(SPPs) including β-Nb with a body-center cubic(BCC) and Zr(Nb, Fe)2 with a hexagonal close packed(HCP) structure and face-center cubic(FCC) structure are observed in Zr-Nb-Fe alloy. The corrosion mass curve breaks away when the Zr-Nb-Fe alloy is corroded for 150 d, then the corrosion rate increases rapidly. Cellular bulge morphology is forms on the external surface of oxide film and the surrounding oxide film is thick and loose. Cellular bulge morphology formed on the tube specimen is roundish compare with that formed on the plate specimen. The hydrogen uptake of specimen after breaking away increases but hydrogen uptake fraction decreases. So the formation of cellular bulge morphology is related to the unabsorbed hydrogen diffusing out through oxide film.
Key words: Zr-Nb-Fe alloy; LiOH solution; cellular bulge; hydrogen uptake fraction
