k8凯发国际

    Corrosion&Coating

    EIS measurements of 4 coating samples

    Source：Corrtest Time：2021-12-22 View：764
    EIS measurements of 4 coating samples
    Aim: to evaluate the protection of coating(through different treatments) on the low carbon steel based on EIS measurements
    Four types of samples:
    #1: coating sample through oiling plate vitrification 
    #2: coating sample through oiling plate phosphating
    #3: coating sample through Chromium-free passivation plate vitrification
    #4: coating sample through Chromium-free passivation plate degreasing
    Corrosion media: 3.5% NaCl solution
    Experiment method: EIS- Frequency
    Experiment Setup: CS350 potentiostat galvanostat,  CS936 flat corrosion cell,(exposure WE area 1cm2. The cell is put in a Faraday cage. )
    Pt mesh (built-in in flat corrosion cell) as CE, CS900 saturated calomel electrodes as RE, Coating sample as WE.
    Parameters setting: AC amplitude is 10mV during measurement, frequency range is 100kHz~0.01Hz, choose “logarithmic” scan, points/decade is “10”.

     
    1. EIS plots of the four samples

    2-1: EIS of #1coating sample through oiling plate vitrification
     

    2-2 EIS of #2: coating sample through oiling plate phosphating

     
    2-3 EIS of #3 coating sample through Chromium-free passivation plate vitrification
     
    2-4 EIS of #4 coating sample through Chromium-free passivation platedegreasing
     
    Impedance of sample #1 and #2
    Table 1 coating impedance data
    Test time/h 0.01Hz coating impedance /Ω•cm2
      #1 vitrification 
         		 #2: phosphating
    24 1.11×109 9.73×108
    72 2.99×109 3.18×109
    240 6.40×109 3.10×109
    480 4.65×109 2.42×109
    Impedance of sample #3 and #4
    Table 2 impedance data
    Test time/h 0.01Hz coating impedance/Ω•cm2
    Sample #3 Sample #4
    24 1.08×109 1.12×109
    72 2.89×109 2.80×109
    240 3.01×109 2.92×109
    480 2.59×108 7.38×108

    3. Conclusion
       (1)Under the same conditions, compared with the sample #2, the impedance of the coating #1 is bigger, indicating that the sample #1 has better anti-corrosion abilities.
       (2) Under the same conditions, compared with the sample #4, the impedance of the coating #3 is bigger, indicating that the sample #3 has better anti-corrosion abilities.

    About Us   Potentiostat/Galvanostat   Accessories   Support   Contact Us  

    Copyright By © 2008-2026 Wuhan Corrtest Instruments Corp., Ltd

    This website stores cookies on your computer. These cookies are used to improve your website experience and provide more personalized services to you, both on this website and through other media. To find out more about the cookies we use, see our Privacy Policy.
    We won't track your information when you visit our site. But in order to comply with your preferences, we'll have to use just one tiny cookie so that you're not asked to make this choice again.
    Decline
    Accept