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A conductive, non-corrosive liquid

  1. Dec 21, 2014 #1
    Hey guys,

    I am working on a project and I need to use use a conductive (even with poor conductivity) but non-corrosive liquid. I don't think that salt water with non corrosive inhibitor is "non-corrosive" enough.

    This is not my major so I am kinda of stuck in the research until I find this, I hope you can give me some names.

    Thank you,
     
  2. jcsd
  3. Dec 22, 2014 #2

    Bystander

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    It's gonna take a little more detail than what you've given. We've played "Goldilocks" before: "How about this?" "Too hot." Have you got temperatures, time frames, other materials you're working with, minimum conductance.
     
  4. Dec 22, 2014 #3

    Astronuc

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    Thermal conductivity or electrical conductivity? What metal alloy is one using for the piping/tubing? What are the temperatures and pressures?
     
  5. Dec 23, 2014 #4
    electrical conductivity, the fluid is not in contact with any piping/tubing, however, I am worried from corrosion in copper coils which will be in contact with the fluid. High temperature (100 - 200 degree C) and high pressure (avg 2500 psi)

    Thank you Astronuc
     
  6. Dec 23, 2014 #5
    Temperature is going to be high (100 to 200 degree C), I don't have a time frame but of course slower corrosion is more time so == much better (if that what you means). I only looked into water with 25% KCl and the electric conductivity was perfect for me, however the corrosion problem showed up and I don't know where/how to start looking for alternatives.

    Thank you
     
  7. Dec 23, 2014 #6

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    Heat exchanger in an electrically heated bath, current flowing through bath, or bath is its own resistance element; high pressure in Cu tubing at 100 - 200 C. Don't tell me, let me guess, oxygen in the tubing at 100-200 C, and the tubing is the cathode for an oxygen/X fuel cell. Gonna be corrosive as all get out.

    Kreskin is not here. Karnak the Magnificent is not here. Kenny Kingston and Madame Cleo are not available. The rest of the membership are not mind readers, and have no way of divining what information might or might not be useful to you. I've just given you an example of what can be put together with vague information and no details of what this is supposed to be, or what it's supposed to accomplish. You're developing a high pressure plating bath for chrome plating rifle bores for all we know, but we can't give you "magic" solutions for sparsely constrained problems.
     
  8. Dec 23, 2014 #7
    I don't want magical solutions, and I am sorry if the information in my question were confusing.
    The help I need is in finding fluids that are non-corrosive, have a conductivity similar to that of salt water with 25% KCl (resistivity around 0.012 ohm.m at 100 C) and can operate at temperature as high as 200 C.
    I know very little in this regard and don't know what other information might be relevant. I also didn't not expect that there are much fluids that satisfy my need (non-corrosive and not bad electric conductor) so that I have to give more information to narrow the options. Please let me know what other information do you see important/relevant.
     
  9. Dec 23, 2014 #8

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    Acetonitrile, and amides are out for the temperature range you require due to decomposition reactions/stability problems. Ethylene carbonate at 200 C? Probably same problems. Aqueous solutions containing dissolved electrolytes at those temperatures are very corrosive. Hg? Does not play well with Cu. You may be looking at an impossible problem, and this is the object of the interrogation --- there may be work-arounds, but no one is going to be able to help you find them without some idea of what you're trying to do.
     
  10. Dec 23, 2014 #9

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    Gallium might be something you could use. Metallurgy with Cu? I've no idea. Reasonably inert. Oxidation resistance at the temperatures you want? Unknown.
     
  11. Dec 24, 2014 #10
    Thank you Bystander
     
  12. Dec 24, 2014 #11

    Astronuc

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    I'm still not sure what fluid one wants in the pipe and outside/external to the pipe (tubing). Which is the hotter fluid?

    Some advanced steels, e.g., 4-7 Mo stainless steels have shown good resistance to hot saltwater. Stainless steels like 254 SMO, 904L, 1925 hMo, 4565, AL-6XN, 654 SMO, and others with Mo up to 8% would probably work.

    http://www.imoa.info/molybdenum-uses/molybdenum-grade-stainless-steels/steel-grades.php

    http://www.swcc.gov.sa/files%5Cassets%5CResearch%5CTechnical%20Papers%5CCorrosion/EFFECT%20OF%20SEAWATER%20LEVEL%20ON%20CORROSION%20BEHAVIOR%20OF%20DIFFERENT%20.pdf [Broken]

    http://www.swcc.gov.sa/files\assets\Research\Technical Papers\Corrosion/CORROSION BEHAVIOR OF SOME CONVENTIONALAND HIGH ALLOY STAINL.pdf [Broken]

    http://www.outokumpu.com/SiteCollec...nce-austenitic-stainless-steel-data-sheet.pdf
     
    Last edited by a moderator: May 7, 2017
  13. Dec 25, 2014 #12

    Vanadium 50

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    There are copper-gallium solders. That would make me want to look more carefully at that.

    Nevertheless, it's clear that the OP doesn't want to describe the application in detail. Fair enough, but that means we'll be playing 20 questions with him. "Nope. It can't be blue".
     
  14. Dec 27, 2014 #13
    Sounds good
    Thank you Astronuc I will give it a try
     
    Last edited by a moderator: May 7, 2017
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