Which Weld Consumable to use

[ZHA]

Hello All,

Design Code - ASME B31.3
I have a dissimilar weld between API 5L X65 and A519 TP 4130 material coming in one of our jobs.
X65 has chemistry of 0.08 - 0.2% C, 0.15 - 0.4% Si, 1 - 1.35% Mn, 0.4% Ni, 0.3% Cr, 0.15%Mo
4130 has chemistry of 0.28 - 0.33% C, 0.15 - 0.35% Si, 0.4 - 0.6% Mn, 0.15% Ni,0.8 - 1.1% Cr, 0.15-0.25% Mo
I plan to use ER100S-G for GTAW and E101T1-G H4 for the above dissimilar welds. We had used the same for 4130 # 4130 welds.
A519 TP 4130 is unclassified material per ASME B31.3. I have referred API RP 582 (Just for reference) and 4130 has chemistry close 1.25 Cr,0.5 Mo and API RP 582 recommends to use the weld consumable which was used for 1.25 Cr, 0.5 Mo even for dissimilar welds between P1 # P4.
Let me know if the consumable I am selecting is correct or do I need to change it.

Thanks in advance.

Regards,
Himanshu Naik

 

[metengr]

What thickness is the DMW joint? Do you intend to PWHT the DMW?

 

[weldstan]

You could use the E/ER100 series which would more closely match the 4130 strength or a lesser strength alloy to more closely match the strength of the X65. It is assumed that the '100G' fillers are nickel-chrome-moly low alloys with low carbon and you have experience with PWHT of them when joining 4130 to itself.

 

[Dhurjati Sen]

Dear Himanshu,

Use ER 70 S - 2 & E 7018-1.

Follow the heat treatment for 1/2% < Cr <= 2% as per B 31.3

Regards.

DHURJATI SEN

 

[ZHA]

- Metengr - 1/2" thickness and yes we intend to do PWHT
- Weldstan - I agree. I plan to go with ER100S-G
- Dhurjati - You cannot use ER70S-2 since the tensile strength is less than that of the base material. X65 has a tensile strength of 78 Ksi.

Thanks and Regards,
HMN

 

[metengr]

I agree with weldstan, but would also consider a 90 series weld rod to buffer the strength mismatch. Regardless, make sure you use extra low hydrogen electrodes, proper cleanliness with suitable preheat to avoid hydrogen cracking.

 

[weldstan]

With same reasoning as metengr, I would also consider a 90 series filler, chemistry similar to E9018-M.