Welding P8 to P10H

[powerplantcwi]

I am looking at a project that will involve welding new a 304ss (P8) vessel to a existing s32101 duplex (p10H) vessel in a paper mill flue gas scrubber system. I am looking for advice on process and choice of filler metal for GTAW, GMAW, and/or FCAW applications, I have seen recommendations on ER309, ERNiCrMo-3, ERNiCrMo-10, ER2209, Zeron 100X, etc. The project will involve a overhead tee joint welded from both sides and horizontal butt joints welded from one side. Does anyone have experience with these? I will have to qualify a new WPS/PQR and would like non-vendor input, as they all assure me their products are the best.

Thanks

 

You could weld it with any of those fillers.
However, you only need to match the corrosion resistance of the less resistant base metal, in this case 304SS. You want to avoid the procedural complications of duplex SS fillers, and also the greater cost and poorer weldability of the Inconel types. 309/309L will do the job. 309L is standard industry practice for welding duplex to austenitic SS and carbon steel, and in fact technical specs often will require it.

"Everyone is entitled to their own opinions, but they are not entitled to their own facts."

 

[metengr]

powerplantcwi;
I like the phrase non-vendor input....You might want to review this document regarding fabrication of Duplex Stainless steel. It will help with your project.

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

 

[DekDee]

metengr,
I didn't recognise the link till I opened it - the International Molybdenum Organisations - Practical Guidelines for Duplex Fabrication has been my bible for many years.

powerplantcwi,
As per ironic metallurgists post and metengrs link it comes down to 2209, 309L or 309LMo
Good luck,
Cheers,
Shane

 

[weldstan]

Not knowing the service conditions at the spec break; nevertheless, I would advise that the weld metal have superior corrosion resistance to that of 304 and all of your selections would suffice in that regard. For ease of welding, I would recommend either 309L or 309LMo.

 

[Dhurjati Sen]

Nobody has recommended ER308L.

What could be the reason?

Regards.

DHURJATI SEN

 

[powerplantcwi]

I have literature stating that 309L is good for welded the lean duplex to itself. one of my vendors is recommending a wire that matches the UNS# of the base. I am leaning toward the 309L for the dissimilar weld so it would definitely make the rod supply easier with less chance of contamination. Any of you have experience using the 309L for welding duplex to itself?