Corrosin resistant material in high chloride, high graphite enviroment
Corrosin resistant material in high chloride, high graphite enviroment
(OP)
Hi,
I'm trying to develop a material that will be stable in a aquous mixture of 10% graphite and 40% wt. chloride salt. It should have a low dissolved oxygen content due to being sealed. As you can imagine, quite corrosive! - plastics not an option.
Where's the best place to start?
Nickle showed signs of nickle chloride after just a day so are nickle alloys a lost cause?
Cheers
I'm trying to develop a material that will be stable in a aquous mixture of 10% graphite and 40% wt. chloride salt. It should have a low dissolved oxygen content due to being sealed. As you can imagine, quite corrosive! - plastics not an option.
Where's the best place to start?
Nickle showed signs of nickle chloride after just a day so are nickle alloys a lost cause?
Cheers





RE: Corrosin resistant material in high chloride, high graphite enviroment
Is the chloride salt just sodium chloride or some combination of non-oxidising cationic salts i.e.
If temperatures/stresses aren't high, why do you think plastics are out?
Graphite is nasty as its extreme electropotential is almost certain to generate galvanic corrosion unless you use a noble metal.
RE: Corrosin resistant material in high chloride, high graphite enviroment
plastics are out as they are not compatable with the rest of the system, otherwise would be ideal!
temp <100 degrees, atmospheric pressure and no stress, although the system will be agitated.
yes just NaCl.
tantalum/silicon carbide coating overkill? bit costly...
thanks
RE: Corrosin resistant material in high chloride, high graphite enviroment
RE: Corrosin resistant material in high chloride, high graphite enviroment
RE: Corrosin resistant material in high chloride, high graphite enviroment
I think salt water on its own would corrodes silver.
about 10 litre inner volume, streached cubiod shaped.
RE: Corrosin resistant material in high chloride, high graphite enviroment
I concur with cloa, some type of ceramic should be considered, due to low stresses/pressure. Depending on the desired durability/life of the system, you may want to consider a Ni-Cr-Mo alloy like C-276 or titanium (ASTM Grade 7, CP + 0.15Pd)?
RE: Corrosin resistant material in high chloride, high graphite enviroment
Have you looked at a Cr alloy such as 33?
At Ti with Ru or Pd (one of the very low %) would be a good option as well.
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Plymouth Tube
RE: Corrosin resistant material in high chloride, high graphite enviroment
We don't know your geometry or anything else about your process, but if it really is "no stress, atmospheric pressure" and nothing else is important, but plastics are out, glass sounds good- unless EdStainless proves me wrong. Or make it out of graphite!
The graphite and the resulting galvanic cell is the problem for the metals. But your conditions aren't all that severe really. Hastelloy C, titanium (as others have noted, added Pd gives some crevice corrosion resistance) would probably do.
Tantalum would too, but would be at risk of embrittlement. Beware- not all tantalum coatings are usefully protective. Have a look at www.tantaline.com - but the sizes they can do are limited and the price can be steep.
RE: Corrosin resistant material in high chloride, high graphite enviroment
I have seen alumina, zirconia, and reaction bonded SiC come apart in hot water due to attack of grain boundary phases.
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Plymouth Tube
RE: Corrosin resistant material in high chloride, high graphite enviroment
A new,low cost material that has very low permiability and good chloride resistance is geopolymer concrete, with many varieties to choose from. Ductility is improved by addition of fibres.
RE: Corrosin resistant material in high chloride, high graphite enviroment
RE: Corrosin resistant material in high chloride, high graphite enviroment
http://www.sub-one.com/breakthrough.html