| The thesis is composed of two parts. The part one is in which corrosion behaviors of 321 or 430 stainless steels in a uranyl nitrate solution, sodium carbonate solution containing sodium uranyl carbonate were studied. The part two is of oxide characteristics of uranium-niobium alloy. Weighing and electrochemical methods have been used to investigate the uniform corrosion and electrochemical corrosion behaviors of carbon steel, stainless steel, and uranium-niobium alloy in corrosion solutions. The thermo-oxide dynamics were studied by P-V-T measurement and thermo-analysis methods. The specimens under the different testing conditions were characteristized with XRD, AES, XPS, SEM, and TEM, in which phase constitutes, element contents, chemical formation, microstructure, and surface micrograph.The chemical properties and electro-deposition of uranium ion in aqueous solution, and the surface oxidation of iron and its alloy, and results of uranium-niobium alloy in corrosion media were reviewed. The conclusions and base parameter from reference were given. The experimental research and theory calculation have been carried out. The uniform corrosion and electrochemical measurement test have been used to investigate interface behavior of uranyl ion in aqueous solution in forming on the surface of carbon steel and 321 stainless steel. The reaction rating reduced in the uranyl nitrate being saturated during film deposit is CO?, which readily reacts with uranyl ion in solution to form uranyl-carbonate complexes. The potentiodynamic polarization results showed that anodic reaction of carbon electrode was activated with uranyl ion in given potential sweep. Electrochemical impedance spectroscopy (EIS) results indicated that the dynamics of carbon steel electrode in uranyl nitrate is complex, in which intermediate compounds were formed onto the surface of carbon steel. The equivalent circuit for a carbon electrode with inductance and constant phase element was released with a low oxidation state of oxide uranium in the interface. The results of carbon corrosion indicated that a novel method was studied for preparation uranium oxide films onto high purity iron in low acidity uranyl nitrate solution.Passive film was formed onto the surface of stainless steel in nitric acid solution. The uniform corrosion results showed that the corrosion rate of 321 stainless steel was less than 0.04g/m2 h in obtained conditions for 40 days, which was adsorbed onto the surface of stainless steel as UO2(NO3)2 6H2O. Stainless steel in the uranyl nitrate containing chlorine ion and hypochlorous acid ion was corroded with pitting. These results confirmed that non-electrochemical reaction is almost for 321 stainless steel in uranyl nitrate solution. 321 stainless steel had a good anti-corrosive performance in uranyl nitrate solution. Thepassive film formed on the stainless steel electrode was made for the potentiodynamic polarization with increasing concentration of uranyl ion, and anodic reaction was enhanced. The uranium oxide film was formed on the surface of 321 stainless steel in the low polarization potential, and the thickness of film is about 80nm, and varied readily with the different potential sweep. Stainless steel had a good antic-corrosive performance in alkalic solution and sodium carbonate containing uranium solution. The electrochemical corrosion results showed uranyl ion have inhibited the anodic reaction of stainless steel electrode in sodium carbonate solution, and stainless steel in 0.06mol/L Na4UO2(CO3)3 was anti-corrosive at 95癈 for 2000h, and Na2U2O7 and UO3 were formed with hydrolysis of uranyl ion.Uranium-niobium alloy have a good anti-corrosive performance when exposed to ambient conditions. The passive film on the surface of uranium-niobium alloy can reduce the reaction rate with oxygen in room temperature, in which niobium oxide influenced dynamics of the alloy. Results showed that dynamics of uranium-niobium alloy accorded with the parabola law. oxide speed constant and activation energy for U-Nb alloy wit...
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