Welding of duplex SS pipe 30 "

[mariolucas75]

Please help me on advise

What critical factors / variables to be considered while welding duplex SS pipes, the environment is marine and there is no fully equipped welding shop...
As a quick research it was advised - "heat input and interpass temperature must be controlled during welding"... what is the key reason to control it ?
Is there anything else ?

Thank so much for your help

 

[XL83NL]

API TR 938-C

 

[EdStainless]

I presume that you are talking about 2205?
And you will use the 2209 filler?
What welding method(s)?
Pure Ar for shield gasses?
If you get too hot you will form intermetallic compounds in the weld metal and/or HAZ.
This will lower the mechanical toughness and significantly lower corrosion resistance.
You also have to be concerned about the austenite:ferrite ratio.
I have written weld procedures for 2205 that resulted in welds with corrosion resistance that would meet the requirements for annealed wrought material.

 

[DekDee]

Please help me on advise

What critical factors / variables to be considered while welding duplex SS pipes, the environment is marine and there is no fully equipped welding shop...
As a quick research it was advised - "heat input and interpass temperature must be controlled during welding"... what is the key reason to control it ?
Is there anything else ?

Thank so much for your help

" and there is no fully equipped welding shop..." - not a good way to start !!!

 

[SJones]

https://www.imoa.info/download_files/stainless-steel/Duplex_Stainless_Steel_3rd_Edition.pdf