Energy From Thorium Discussion Forum

It is currently Jul 22, 2018 11:13 pm

All times are UTC - 6 hours [ DST ]




Post new topic Reply to topic  [ 5 posts ] 
Author Message
PostPosted: Apr 23, 2015 6:41 am 
Offline
User avatar

Joined: Jul 14, 2011 9:22 pm
Posts: 31
Location: Forest Park, GA
So I just finished my first exposure test of 316L in FLiNaK.

The corrosion from the 316, presumably iron and chromium fluorides, are quite thick in the FLiNaK. Raw FLiNaK was a light green color, while the crucibles containing the 316 had the color of a dark wine.

Now this makes me wonder.

I know that my tests were done in open atmosphere leading to accelerated corrosion rates. And I know that 316L isn't exactly being considered as a major design material. But has anyone looked into the changes in material properties of the salt as it takes on corrosion products? I noticed a significant change in viscosity, and this was only a 24 hour test.

Is this something with a research base, or should I put it on my to do list?


Attachments:
File comment: Molten FLiNaK in alumina crucible. Some contamination from corrosion layer on furnace lid.
20150422_163708[1].jpg
20150422_163708[1].jpg [ 2.82 MiB | Viewed 3146 times ]
File comment: Three crucibles that held samples of 316L in FLiNaK eutectic. FLiNaK poured off and coupon removed.
20150422_162559[1].jpg
20150422_162559[1].jpg [ 2.61 MiB | Viewed 3146 times ]
Top
 Profile  
 
PostPosted: Apr 23, 2015 11:29 am 
Offline
User avatar

Joined: Oct 06, 2010 9:12 pm
Posts: 138
Location: Cleveland, OH
Won't you get some contamination from the crucible, too?


Top
 Profile  
 
PostPosted: Apr 23, 2015 11:59 am 
Offline
User avatar

Joined: Jul 14, 2011 9:22 pm
Posts: 31
Location: Forest Park, GA
That's to be determined. Theoretically there should be some odd aluminates forming.
The empty crucibles are actually there to analyze just that. They're going to be ran under X-Ray Diffraction to see if anything formed at the interface between the salt and the alumina.

In practicality, there wasn't any visible corrosion of the alumina. Although this was only for 24 hrs at 750 C.
Also, AlF3 is colorless, while Ferrous Fluoride is a red-violet color. This fits perfectly with the observed FLiNaK color in the crucibles containing 316L.

But I will be investigating the corrosion of alumina as part of my research.


Top
 Profile  
 
PostPosted: Apr 29, 2015 8:23 am 
Offline
User avatar

Joined: Oct 06, 2010 9:12 pm
Posts: 138
Location: Cleveland, OH
Will you be also testing at some lower temperature regimes, say 500 to 650 C? There are many pieces of equipment and piping for most MSR implementations that would be operating at those temperatures rather than the temps for the reactor vessel and heat exchangers.


Top
 Profile  
 
PostPosted: May 02, 2015 6:22 pm 
Offline

Joined: Jul 28, 2008 10:44 pm
Posts: 3065
You should search the ORNL docs - I've heard they did clean molten salt tests with 316 and the results were very good. But oxygen is precluded from most MSR designs and is considered a significant problem - so I wouldn't put any importance to open air results.


Top
 Profile  
 
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 5 posts ] 

All times are UTC - 6 hours [ DST ]


Who is online

Users browsing this forum: No registered users and 1 guest


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Search for:
Jump to:  
cron
Powered by phpBB® Forum Software © phpBB Group