• Login
    View Item 
    •   Home
    • Theses & Dissertations
    • 2019 - Mines Theses & Dissertations
    • View Item
    •   Home
    • Theses & Dissertations
    • 2019 - Mines Theses & Dissertations
    • View Item
    JavaScript is disabled for your browser. Some features of this site may not work without it.

    Browse

    All of Mines RepositoryCommunitiesPublication DateAuthorsTitlesSubjectsThis CollectionPublication DateAuthorsTitlesSubjects

    My Account

    Login

    Mines Links

    Arthur Lakes LibraryColorado School of Mines

    Statistics

    Display Statistics

    Thermal spray cladding optimization for steel drill pipe

    • CSV
    • RefMan
    • EndNote
    • BibTex
    • RefWorks
    Thumbnail
    Name:
    Ott_mines_0052N_11738.pdf
    Size:
    6.431Mb
    Format:
    PDF
    Download
    Author
    Ott, Wesley L.
    Advisor
    Yu, Zhenzhen
    Date issued
    2019
    Keywords
    iron based cladding
    oxide characterization
    voltage parameter
    MPEA
    droplet behavior
    thermal spray
    
    Metadata
    Show full item record
    URI
    https://hdl.handle.net/11124/173072
    Abstract
    Thermal spraying is commonly used to apply a hard and wear resistant coating to the outside of drill pipe. These coatings, however, are susceptible to impact damage and brittle fracture. A fundamental understanding is needed for the relationship among wire composition, spray parameters, and developed microstructure to improve coating toughness and bonding strength to the substrate. Characterization of the coating’s main features was determined by optical microscopy (OM) and scanning electron microscopy (SEM) analysis. Effect of process parameter voltage was evaluated by four-point bend testing with digital image correlation and Vickers and nano-indentation testing across the coating-substrate interface. It was found that as the voltage increased, the number of defects, primarily oxides, decreased. The decrease in oxide content led to increased coating strength at the higher voltage conditions. The oxide concentration did not exhibit a linear relationship with voltage, indicating that no significant change would occur above 36.5V. A new composition coating was proposed to increase strength and toughness while still maintaining wear properties. The new multi principle element alloy (MPEA) coating composition (Fe0.32Co0.08Cr0.2Ni0.32Mo0.07Ta0.01) was based on favorable findings reported for the FeCoCrNiMo0.2 MPEA. Two wires of different material were arced together to form the final coating. The effect of spray pressure on the mechanical properties of the coatings was evaluated by four-point bend testing, Vickers hardness, and dry sand rubber wheel wear testing. OM and SEM characterizations were performed on the new coatings. It was found that the anode and cathode wires did not mix within the arc, during flight, or upon deposition resulting in a coating with two different splat compositions. An increase in spray pressure from 172 to 310 kPa, resulted in the dramatic increase in oxide concentration from 21% to 64% but an 8% decrease in outer-fiber stress. The maximum new coating strength was found to be two times that of the HH1 coating. The wear rate was over three times greater than that of the HH1 coating. The two spray pressure conditions tested exhibited virtually the same wear rate suggesting that the spinel oxides responsible for the exceptional wear behavior of the FeCoCrNiMo0.2 MPEA did not form due to the lack of mixing.
    Rights
    Copyright of the original work is retained by the author.
    Collections
    2019 - Mines Theses & Dissertations

    entitlement

     
    DSpace software (copyright © 2002 - 2023)  DuraSpace
    Quick Guide | Contact Us
    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.