ammonia-steel 1

[arceki]

I'm looking for some values for corrosion rate of ammonia in contact with some stainless steels 304-(L),316-(L).
And carbon steel, I've looking very hard but I could't find anything just for 316 and carbon steel 1020.
Thanks in advance.

 

[micalbrch]

Check the attached file. Not perfect but at least better than nothing.

 

[arceki]

Thanks micalbrch¡¡¡¡¡¡ it was useful, and thanks for answering so quickly¡¡¡

 

[Guest102023]

arceki, is this application for urea service?

 

[EdStainless]

Unless you are at extreme temperature, pressures, and concentrations; any SS will have a near zero corrosion rate.
We have supplied high alloy SS grades for use in ammonia heat exchangers cooled with seawater.

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Plymouth Tube

 

[arceki]

Ok thank you all.

 

[strider6]

have a look at this paper from NIDI, you can download it for free, just register to the site:

Stainless Steels in Ammonia Production (9013)

Discusses selection of stainless steels from process equipment in ammonia production plants. Contains 22 diagrams, charts, and tables illustrating a typical ammonia production process, and provides technical data on 18 stainless steels that might be used for construction materials. Also covers materials for desulphurization, catalytic steam reforming, carbon monoxide shift, carbon dioxide removal, methanation, synthesis, and turbine-driven centrifugal compression trains. Provides data on the candidate stainless steels.

http://www.nickelinstitute.org/index.cfm/ci_id/15786/la_id/1/ci_doc_id/3135/st_id/13/level/3.html

hope this help

S

Corrosion & Rust Prevention Control

 

[TomEun]

In addition to above valuable references, please find below if you need more information.

- MTI, Materials Selector for for Hazardous Chemicals, MS-6: Ammonia and Caustic Soda
- NACE Conference Paper 03523 Stress Corrosion Cracking of Austenitic Stainless Steel in Fertilizer Plants
- NACE Conference Paper 02439 External SCC Phenomena of Austenitic Stainless Steel in Urea Plants

Thomas Eun

 

[MrMyers]

Carbon steels in anhydrous ammonia service can suffer from stress corrosion cracking if the water content is less than about 0.1%, with the presence of oxygen (also small ppm).

There is some good information available from European Fertiliser Manufacturers Association (EFMA) about this.

I've seen many production plants use low/medium strength plate and weld materials (~300 MPa yield), with PWHT included.

Vapour spaces of vessels are also at risk of SCC, due to the water content of the vapour being 0%.

Risk of SCC increases with increasing temperature, oxygen content and hardness.

Finally, general corrosion/thinning is not a mechanism usually considered for carbon steel in anhydrous ammonia service, but is probably a consideration for aqueous ammonia.