Welding disimilar stainless steel
Welding disimilar stainless steel
(OP)
Is it ok to weld 316SS to 2205(duplex) stainless steel.
On a seawater RO(quite high pressures) the duplex is the pipework and the 316 is a ball valve.
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Welding disimilar stainless steel
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RE: Welding disimilar stainless steel
I would upgrade the valve material to an Alloy 20. This material can be welded to the Duplex 2205 using a nickel-base filler metal. The interpass temperature must be less than 300 deg F during welding.
RE: Welding disimilar stainless steel
I wouldn't bother with 904L. It is expensive (high Ni) and not very corrosion resistant. Go to a 6%Mo alloy.
If you do need to weld an autenitic stainless to a duplex you will want to use a high alloy austenitic filler so that the weld is austenitic. If the weld is 'sort of' duplex you can get some very poor mechanical properties.
If I were welding 316L to 2205 I would use a 6% Mo filler.
If I were welding a 6%Mo stainless to 2205 I would use a 'C' type Ni-Cr-Mo alloy (C-276 or similar).
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Corrosion never sleeps, but it can be managed.
http://www.trenttube.com/Trent/tech_form.htm
RE: Welding disimilar stainless steel
RE: Welding disimilar stainless steel
The NiCrMo-3 (625) fill is a good idea Stan. It is versitile, strong and corrosion resistant.
= = = = = = = = = = = = = = = = = = = =
Corrosion never sleeps, but it can be managed.
http://www.trenttube.com/Trent/tech_form.htm
RE: Welding disimilar stainless steel
sorry my mistake! its not seawater. Just brackish water.
Appreciate all your answers though.
So just to confirm it will be 316 to 2205.
RE: Welding disimilar stainless steel
RE: Welding disimilar stainless steel
rmw
RE: Welding disimilar stainless steel
we are using 316 and 2205 SS
im not exactly sure of the feed water quality.
The materials have been specified by the client.
We had a 316SS ball valve with threaded BSP fittings and they wanted us to machine a new 2205 end.
However our fabricator has informed me that he can just machine out the thread and socket weld the 2205 into the 316
I just wanted to check that this was ok.
RE: Welding disimilar stainless steel
RE: Welding disimilar stainless steel
http://www.outokumpu.com
Here is how to get to the document at the above site.
Page: Home / Stainless Home / About us / Divisions / North America / Publications, North American Division
RE: Welding disimilar stainless steel
A 6%Mo austenitic stainless filler would be a good option. Your filler must have higher Mo than either of the materials that you are joining in order to get decent weld metal corrosion resistance.
And as always, clean welds are good welds. Good shielding and post-weld acid cleaning will go a long way.
= = = = = = = = = = = = = = = = = = = =
Corrosion never sleeps, but it can be managed.
http://www.trenttube.com/Trent/tech_form.htm