Study On Preparation Process And Corrosion Resistance Of B10 Cu-Ni Alloy Chemical Conversion Film

In this paper,based on the fact that B10 Cu-Ni Alloy due to its excellent anti erosion corrosion property in seawater,is the used widely as piping material in seawater for the research background.In view of to the demand corrosion resistance and anti-erosion property to B10 Cu-Ni Alloy surface,we conduct the research that the B10 Cu-Ni Alloy surface modification technology to improve the alloy surface anti erosion corrosion property in seawater.The article elaborates two parts of content.The first part is the technology research of B10 Cu-Ni Alloy cerium nitrate chemical conversion film and the mechanism why the chemical conversion film own excellent corrosion resistance in seawater.The second part is the exploration to B10 Cu-Ni Alloy electrochemical conversion film technology under the cerium nitrate environment.Primarily,the article explores the process of cerium nitrate chemical conversion film,discusses a series of parameters for the film forming process,and illustrates the influence of pH value,reaction temperature and the validity period of solution three aspects to the conversion film,ultimately determine the optimal parameters of the process.What's more,the article analyses the morphology characterization and chemical composition of chemical conversion film made by the optimum process conditions through scanning electron microscopy?SEM/EDX?and electron energy spectrum analysis?XPS?.The results show that the conversion film surface is uniform and no obvious defects.The percentage of Ce in conversion film is higher,and the rare earth Ce of the conversion film mainly exist in Ce⁴⁺as oxide or hydroxide such as CeO?OH?₂,CeO₂ andanother part of complex Ce/Cu/Ni corporate oxide or hydroxide.Finally,using the electrochemical impedance spectroscopy?EIS?continuous test the changes of the corrosion resistance for the cerium nitrate chemical conversion film in seawater,and analyzes the reason and the mechanism of the film owning the excellent corrosion resistance in detail.The analysis shows that the conversion film immersing still keep excellent corrosion resistance at least 3 months?2476h?in seawater.The cause of excellent corrosion resistance for the chemical conversion film is that there is a special process of transfer-repair-densification on the basis of the mass transfer between the seawater and the film.Another point is the effect of crosslinking and occlusion of the Ce complex oxide and hydroxide in the conversion film.Secondly,in view of the shortcomings of the pure cerium nitrate chemical conversion film process,the article explores the possibility using electrochemical treatment to create cerium salt conversion film on Cu-Ni Alloy surface.The specific process includes:1.Anodic polarization?increasing potential cycle scan?;2.Alternating current?AC?passivation;3.BTA corrosion inhibitor process.In addition,according to the characteristics of the cerium salt conversion technology,the experimental design innovates the anodic polarization,optimizes the parameters in part of the process.Each part of the process specially uses different electrochemical test methods to track test for indicating effect of every process.The result preliminary characterizes anti erosion corrosion property of the electrochemical conversion film under the cerium nitrate environment in seawater to B10 Cu-Ni Alloy.The exploration of new technology also provides a possible method for more advanced chemical conversion technology.