الفهرس | Only 14 pages are availabe for public view |
Abstract 1- The corrosion of zirconium, Zircaloy-2, and Zircaloy-4 in pure deionized water, lithium hydroxide aqueous solution, and mixtures of lithium hydroxide and boric acid aqueous solution have been studied using cyclic potentiodynamic polarization technique. 2- A review of waterside corrosion data, including information available in the present work, it was found that the Zr-4 waterside corrosion closely follows the zirconium and Zr-2 corrosion at room temperature and increasing corrosion resistance to lithiated solutions in the order Zr > Zr-4 > Zr-2. 3- In LiOH aqueous solution, it was found that the corrosion rate of the three specimens is accelerated in high concentration of LiOH. By contrast, moderate concentrations of LiOH solutions at room temperature appear capable, at most, only of generating superficial pores in oxide films. The mechanism which was suggested for acceleration corrosion is the porosity generation model. 4- In mixtures of LiOH and H3BO3 aqueous solution, it is clear from the present study that the presence of boron as boric acid abates the deterioration effect of LiOH on the corrosion resistance of the materials and the corrosion rate slows down than those in LiOH aqueous solution only. 5- from the cyclic potentiodynamic polarization curves, the uniform corrosion is the dominant and localized corrosion appears at some certain concentration values of LiOH in absence of boric acid. 6- The appearing of erratic results, irreproducible, has limited the ability to quantify the effect of lithium in corrosion process and a contributing in accelerated uniform corrosion of nuclear fuel cladding material,Zircaloy. |