Welding Consumable for Welding Super Duplex UNS32750 to UNS32760 1

[xuanthien]

Dear My Friends,

My project have to qualify 1 PQR between Super Duplex A790 UNS 32750 to Super Duplex A790 UNS 32760. Mechanical test require:

1. Pitting Corrosion at 40 Degree (No Pitting)
2. Range Ferrite: 35-65%.
3. Max Hadness 350 HV10

I am wondering which consumable we should use, ER2594 Metrdoe 2507 or ER2594 Metrode Zeron 100X.

What is different between metrode 2507 and metrode Zeron 100X. Pls give your recommendation.

 

[metengr]

Based on excellent experience, I would use ER2594 wire by Sandvik

http://www.smt.sandvik.com/en/mater...welding-products/welding-wire/sandvik-25104l/

I have used Metrode products, but not on superduplex.
If you need to use Metrode, I would probably go with Zernon 100X for wire.

 

[EdStainless]

I agree.
Clean and very dry, Nitrogen in both weld and backing gas (5% and 10% respectively).
Minimum heat input, minimize temp rise.

= = = = = = = = = = = = = = = = = = = =
P.E. Metallurgy, Plymouth Tube

 

[xuanthien]

Hi Edstainless,

If we qualify with minumun heat input, Ferrite content shall be increased 65%. I think the best heat input within arange 1-1.5Kj

 

[weldstan]

That is why Rd has recommended the Nitrogen in both the purge and shielding gas. Nitrogen is an austenite former.

 

[weldstan]

Sorry. "Why Ed..."

 

[EdStainless]

I knew what you meant Stan.

You need nitrogen in welds for both phase balance and to keep the pitting resistance up.
You need to keep heat input down to prevent forming detrimental secondary phases in the HAZ.

All welds in these materials should have corrosion testing as part of the qualification.
I would require testing of both a coupon of the as-weled joint and a coupon of weld metal and HAZ that had all surfaces freshly ground. The first one measure the pitting resistance and the second one measures the formation of detrimental phases.

= = = = = = = = = = = = = = = = = = = =
P.E. Metallurgy, Plymouth Tube

 

[Duwe6]

further, N2 also tends to increase strength in superalloys. That is where the "N" comes from in AL6XN. Should give a small improvement in your duplex.