Welding between duplex and inconel/SS316L

[Giuseppe76]

We would need to perform a pipe-to-pipe welding for dissimilar materials (duplex-Inconel and Duplex-SS316L), I am not a welding eng so I would like to know if someone has experiences on that and which is your advice in terms of process and filler materials.

rgds

 

[metengr]

What size pipe (diameter) and wall thickness? Typically, the filler metal for duplex stainless to Inconel will be similar to ENiCrFe-3 and for duplex to stainless steel, 2209 or E309MoL. Among other parameters to consider - weld joint detail, cleanliness, no preheat, and strict monitoring of interpass temperature (less than 350 deg F).

 

[stanweld]

What Grade of Inconel? Alloy 600, Alloy 625? What grade of Duplex - 2205?
What is the service fluid?

 

[Giuseppe76]

Several dimensions ( are for few umbilicals with main and internal pipes). Grades should be 2205 and 625 or 316L, with water and oil.
I let you know once I have more info.

which is the best process in that cases?

thanks

 

[stanweld]

2205 to 625: use ERNiCrMo-3 or up alloy to ERNiCrMo-4 or better.
2205 to 316L: see metengr.
Best process will depend on economy as well as quality. Rrecommend GTAW and/or GMAW.

 

[Giuseppe76]

I recover the dimensions:

- 12.7 x 1.47 mm
- 19.05 x 1.1 mm
- 12.7 x 1.0 mm
- 28.58 x 1.47 mm

The main pipe is a plastic sheath.

thanks for your help

 

[wegm]

In addition, you could have a look at this link:

http://www.weldinguide.com/viewtopic.php?f=2&t=9

 

[birken]

Duplex 2205 to Inconel 625:
P.No. 10H to 43
Pre-heat: 10 C (50 F)
Filler wire (GTAW): ERNiCr-3 (AWS 5.14)
Interpass temperature: 150 C (300 F) max.
Electrode (SMAW): ENiCrFe-3 (AWS 5.11)
PWHT: None

Duplex 2205 to SS316L:
P.No. 10H to 8
Pre-heat: 10 C (50 F)
Filler wire (GTAW): ER309 (AWS 5.9)
Interpass temperature: 150 C (300 F)
Electrode (SMAW): E309-16 (AWS 5.4)
PWHT: None

Birken

 

[Giuseppe76]

Thanks,

Very usefull

 

[stanweld]

Birken,
Straight 309 and ERNiCr-3 would not be recommended. Neither filler metal would have the corrosion resistance in the environment for which the base metals were selected.

 

[wegm]

Sorry, the above link doesn't work, you could have a look at this link:

http://www.weldinguide.com/gdanastasiadis/viewtopic.php?f=2&t=9