Welding 304 Stainless sheet for ammonia atmosphere 2

[kellnerp]

I need to make a vertical weld in 304 SS 0.187 thick. The weld carries load and so must be sound. Any thoughts as to what the process should be? I was planning on using ER316L wire and MIG from one side.

 

[Goahead]

I am always amazed when 304 is selected for welding.
It should be known that sensitization (that is precipitation of chromium carbides) will follow, depleting of chromium the material near the weld and preparing a preferred path for intergranular attack.
Standard precaution would be to select 304L or 321 instead, with 347 filler metal.
If 316 is not needed as base metal, what should it contribute in the weld bead?

http://www.welding-advisers.com/

 

[EdStainless]

You get a lot of weld segregation is stainless, the welds will have less pitting resistance than the base metal. The common choice is to use overalloyed filler. In this case though, I don't recal that Mo helps you in ammonia.

Make sure that you use 304L. If you really feel that you need overalloyed filler consider 309L.


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Corrosion, every where, all the time.
Manage it or it will manage you.

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