• Login
    View Item 
    •   Home
    • UA Graduate and Undergraduate Research
    • UA Theses and Dissertations
    • Master's Theses
    • View Item
    •   Home
    • UA Graduate and Undergraduate Research
    • UA Theses and Dissertations
    • Master's Theses
    • View Item
    JavaScript is disabled for your browser. Some features of this site may not work without it.

    Browse

    All of UA Campus RepositoryCommunitiesTitleAuthorsIssue DateSubmit DateSubjectsPublisherJournalThis CollectionTitleAuthorsIssue DateSubmit DateSubjectsPublisherJournal

    My Account

    LoginRegister

    About

    AboutUA Faculty PublicationsUA DissertationsUA Master's ThesesUA Honors ThesesUA PressUA YearbooksUA CatalogsUA Libraries

    Statistics

    Most Popular ItemsStatistics by CountryMost Popular Authors

    Stability of Metal in Molten Chloride Salt at 800˚C

    • CSV
    • RefMan
    • EndNote
    • BibTex
    • RefWorks
    Thumbnail
    Name:
    azu_etd_15228_sip1_m.pdf
    Size:
    6.809Mb
    Format:
    PDF
    Download
    Author
    Alkhamis, Mohammad
    Issue Date
    2016
    Keywords
    Metal
    Molten Chloride Salt
    Ni-alloy
    Corrosion
    Advisor
    Gervasio, Dominic
    
    Metadata
    Show full item record
    Publisher
    The University of Arizona.
    Rights
    Copyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.
    Abstract
    The stability of Haynes 230 and Hastelloy C-276 nickel alloys exposed to high temperature molten salt with trace contaminants (i.e., water and oxygen) is found to be acceptable for using these metals to house anaerobic MgCl2-KCl and NaCl-KCl-ZnCl2 molten salts at 800oC. The corrosion rate determined by gravimetric tests range from -98 µm/year to 20. 13 µm/year at 800˚C. The corrosion rate is estimated to be 16.14 µm/year for Haynes 230 and 10.03 µm/year for Hastelloy C-276 based on the weight loss and surface area of the coupons when the coupons of Haynes 230 and Hastelloy C-276 alloys are immersed in molten MgCl2-KCl salt in sealed quartz containers and left in an oven at a temperature of 800˚C up to 16 days. The corrosion rate is estimated to be -20.46 µm/year for Haynes 230 and -7.36 µm/year for Hastelloy C-276 based on the weight loss and surface area of the coupons when the alloys are immersed in molten NaCl-KCl-ZnCl2 salt in sealed quartz containers and left in an oven at 800˚C up to 56 days. The corrosion rate of the alloys are well below the DOE requirement of 50 µm/year for the alloys in molten chloride salts to be considered acceptably stable. Ultimate tensile strength (UTS) after immersion of Haynes 230 and Hastelloy C-276 in molten salt ranged from 634 MPa to 860 MPa. The UTS of Haynes 230 is estimated to be 642 MPa after exposure to NaCl-KCl-ZnCl2 for 4 weeks at 800˚c and 841 MPa after exposure to MgCl2-KCl for 4 weeks at 800˚c compared to an untreated sample which achieved a UTS of 851 MPa. Likewise, the UTS of Hastelloy C-276 is estimated to be 692 MPa after exposure to NaCl-KCl-ZnCl2 for 4 weeks at 800˚c and 842 MPa after exposure to MgCl2-KCl for 4 weeks at 800˚c compared to an untreated sample which achieved a UTS of 830 MPa. Molten chloride salts, such as NaCl-KCl-ZnCl2 and KCl-MgCl2, are pretreated by heating and bubbling dry Argon gas in the salt in order to remove oxygen and water and thereby reduce the corrosion of metal containers of molten salt. Monitoring the relative humidity and percent oxygen of the exhaust gas during the sparging of dry Argon at 240 sccm into 150 g of molten chloride salt at 500˚C for NaCl-KCl-ZnCl2 and 700˚C for KCl-MgCl2 allows an estimation time to reach a low level of oxygen and water in the salt and to estimate the amount of oxygen and water removed. Results show water is more difficult to remove than oxygen from the salt. Ten minutes of sparging with dry argon brings oxygen content of exhuast gas to<0.1% O2. Approximately fifty minutes of sparging leaves the exhaust gas only containing<0.7% RH. The total moles of oxygen removed from the salts are estimated to be 0.0043 moles for molten NaCl-KCl-ZnCl2 and 0.0076 moles for KCl-MgCl2. The total moles of water removed from the NaCl-KCl-ZnCl2 salt is estimated to be 0.016108379 moles and 0.002321214 moles from molten KCl-MgCl2.
    Type
    text
    Electronic Thesis
    Degree Name
    M.S.
    Degree Level
    masters
    Degree Program
    Graduate College
    Chemical Engineering
    Degree Grantor
    University of Arizona
    Collections
    Master's Theses

    entitlement

     
    The University of Arizona Libraries | 1510 E. University Blvd. | Tucson, AZ 85721-0055
    Tel 520-621-6442 | repository@u.library.arizona.edu
    DSpace software copyright © 2002-2017  DuraSpace
    Quick Guide | Contact Us | Send Feedback
    Open Repository is a service operated by 
    Atmire NV
     

    Export search results

    The export option will allow you to export the current search results of the entered query to a file. Different formats are available for download. To export the items, click on the button corresponding with the preferred download format.

    By default, clicking on the export buttons will result in a download of the allowed maximum amount of items.

    To select a subset of the search results, click "Selective Export" button and make a selection of the items you want to export. The amount of items that can be exported at once is similarly restricted as the full export.

    After making a selection, click one of the export format buttons. The amount of items that will be exported is indicated in the bubble next to export format.