31254 Clad Vessel Welding Filler Wire/Electrode

[bmoorthy]

Hello all

Background:
In a 25 MM thick Carbon Steel plate(SA 516 Gr 60), 3mm SA 240 Gr 31254 is clad (Explosion Bonded).

This is rolled into a 1800 mm (ID) Shell for a Pressure vessel (U stamped vessel).

The Longitudinal seam is first welded (carbon Steel welding done with 7018-1, MDMT -29 Deg C, No Production coupon, No Impact). Subsequently 31254 is to be restored.

Nozzles are planned to be overlayed (Lowest size of nozzle is 4").
Expected Undiluted chemistry of 2mm (31254)

Question is

1) Can is use Barrier layer as Inconel (As suggested in ASME II C) and final layer with 31254 Wire? ASME or AWS suggests Inconel filler.

I am unable to find a 31254 filler wire (when i did a search, i could not find 31254 filler wire).

2) For Nozzles ID deposition (Planned with GTAW), here again if i perform barrier with Inconel (Er Ni Cr Mo-3 or Er Ni Cr Mo-12) and subsequently with 31254 Wire, is it OK?

Of course i will conduct PQR as per ASME.

The reason for this question is that, Neither ASME/AWS specifies 31254 filler nor does the manufacturer brouchers for SMO 254 (et al) specify 31254 filler wire.

3) The larger question: Suppose for another vessel/Exchanger where there is a pressure butt joint between 31254 Nozzle pipe and nozzle flange,
Can you simply procure a specified alloy wire (Not necessarily classified as filler wire) and use it as a filler wire for weld deposit?

 

[metengr]

Can you simply procure a specified alloy wire (Not necessarily classified as filler wire) and use it as a filler wire for weld deposit?

If this vessel is being built to ASME Section VIII, Div 1, you will need to develop a code case for using filler metal that is comparable to UNS 31254. Also, having a custom filler metal is expensive.

If you review ASME Section VIII, Div 1, Part UHA, UHA-42, Weld Metal Composition, the suggested filler metal for UNS 31254 is ENiCrMo-3,ERNiCrMo-3 or ENiCrMo-12.

 

[SJones]

I wouldn't follow option 3 since wire products will not have been formulated to counter for the effects of welding. You can try - but, if I was the purchaser of the vessel, I would be getting you to do a G48 test for the PQR so you might have to examine consumable choice a bit more carefully.

Steve Jones
Materials & Corrosion Engineer

http://www.pdo.co.om/pdo/

 

[stanweld]

There is a high potential for cracking when welding into Ni base alloys like the NiCrMo alloys with duplex stainless and stainless steel alloys. Use the NiCrMo-3 or NiCrMo-12 alloy for clad restoration and fill.