(1. 上海大學(xué) 微結(jié)構(gòu)重點實驗室，上海 200444；
2. 上海大學(xué) 材料研究所，上海 200072)
摘 要: 采用靜態(tài)高壓釜腐蝕實驗研究添加微量Pd元素的Zr-4合金在(360 ℃，18.6 MPa)條件下0.01 mol/L LiOH水溶液中的耐腐蝕性能，采用TEM和SEM研究合金和氧化膜的顯微組織。結(jié)果表明：添加0.05%~0.2% Pd(質(zhì)量分?jǐn)?shù))均可明顯改善Zr-4合金在LiOH水溶液中的耐腐蝕性能，其中添加0.1% Pd時改善作用最顯著，隨著添加Pd含量的進(jìn)一步增加，對Zr-4合金耐腐蝕性能的改善作用減弱。在Zr-4合金中Pd元素以Zr2(Fe,Cr,Pd)、Zr2(Pd,Fe)形式的第二相析出，其中Zr2(Pd,Fe)第二相尺寸較大。固溶在α-Zr中的Pd和尺寸較小的Zr2(Fe,Cr,Pd)型第二相可以提高Zr-4合金的耐腐蝕性能；析出尺寸較大的Zr2(Pd,Fe)第二相后會對Zr-4合金的耐腐蝕性能產(chǎn)生不利的影響。
關(guān)鍵字: 鋯合金；Zr-4合金；耐腐蝕性能；氧化膜
（1. Laboratory for Microstructures, Shanghai University, Shanghai 200444, China;
2. Institute of Materials, Shanghai University, Shanghai 200072, China）
Abstract:The corrosion resistance of Zr-4 alloy with Pd addition in 0.01 mol/L LiOH solution at 360 ℃ and 18.6 MPa was studied by autoclave test. The microstructures of the alloys and oxide layers were investigated by TEM and SEM. The results show that the corrosion resistance of Zr-4 alloy in LiOH solution is markedly improved with the addition of 0.05%-0.2% Pd. And the Zr-4 alloy with the addition of 0.1%Pd shows the best corrosion resistance. The role of improving the corrosion resistance of Zr-4 alloy weakens when the Pd content further increases. The alloying element of Pd is precipitated as the second phase particles (SPPs) of Zr2(Fe,Cr,Pd) and Zr2(Pd,Fe) in Zr-4 alloys. The SPPs of Zr2(Pd,Fe) are comparably coarse. The solid solution of Pd in α-Zr matrix and the precipitates of fine SPPs of Zr2(Fe,Cr,Pd) are beneficial to improve the corrosion resistance of Zr-4 alloy, while the coarse SPPs of Zr2(Pd,Fe) are harmful to the corrosion resistance.
Key words: zirconium alloy; Zr-4 alloy; corrosion resistance; oxide film
