Weld Overlay / Stress Relieving 2

[CRAMETAL]

Hi Gents,

We have AISI 4130 Flange welded with a pipe (P1 group material 25 mm WT) and stress relieved. Is it acceptable to clad internally with Inconel 625 by weld overlay on stress relieved spool? Can any one please advise on the WPS / PQR requirement?

Thanks!

 

[metengr]

BAALAAS;
You need to answer the questions below before a reasonable recommendation can be made.

What is the service application of the above item?
What is the applicable construction code for this item?

 

[EdStainless]

If it were mine I would require PWHT. since this is a hardenable steel you had to SR after welding, why would overlay be any different?

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Plymouth Tube

 

[metengr]

With adequate preheat applied to the 4130 you may be able to work around PWHT, as is currently allowed for other low alloy steels. For an overlay the thickness which typically governs PWHT is the nominal thickness of the overlay, and not necessarily the wall thickness of the substrate.

 

[stanweld]

Are you overlaying the entire spool? If so and the carbon steel wall thickness is such that PWHT is not required, I would overlay the pipe independently of the the flange. I would make the butt weld joining the overlayed flange to the overlayed pipe with ER/ENiCrMo-3 weld filler metal. I may or may not PWHT depending on hardening issues and thermal cycling service issues and service fluid.

Per ASME IX you will need two overlay PQRs, one for the 4140 and one for the P1 material. You will also need at least one butt welding PQR.

 

[CRAMETAL]

Thanks to all.

Hi Metengr:

The Service Application: Sweet and wet Sour Gas service
Design Code: B31.8

Hi EDStainless:

We will get the flange (API 10M) weld with A694 transition piece (both carbon steel) and stress relieved from one vendor. Then it shall be cladded interanlly (inconel) by another vendor. Can it be cladded after stress relieving?

Hi Stanweld, Thanks. please see above the requirement and give your opinion.

 

[metengr]

Review ASME B31.8, B825 Stress Relieving under B800, which is in Chapter IX, Sour Gas Service. You will need to stress relieve.

 

[SJones]

The principal decision driver will be whether it is required to hit 250 HV10 max in the low alloy steel and carbon steel to comply with ISO 15156. The end user has the option to waive this requirement if they have the confidence in the cladding integrity for the design lifetime. Is the hardness requirement being imposed?

Steve Jones
Materials & Corrosion Engineer

http://www.linkedin.com/pub/8/83b/b04

 

[CRAMETAL]

Hi SJones,

Thanks for your response. Yes, the hardness shall not exceed 250 HV.

 

[jbeckhou]

I would suggest using AISI 4130 L80 mech. tubing instead of pipe for this project. Require only one WPS. Since your welding on API-6A flanges, suggest reviewing API-6A welding requirements. If I remember correctly, NACE requires PWHT.

See the attached link for information about PWHT.

Petrotrim Services
www.petrotrim.com