Cooper/Nickel (Orbital)

[GemmellG]

Developing a Cooper/Nickel(Orbital)welding procedure Material is 4" Sch40 ASTM B466 UNS-C70600 Weld Filler ERCuNi(67). Shielding gas Argon 100% Back Purge Argon 100%. Applying hot pass is were we are having issues. Does anyone have any ideas as I have run out. Attached is a photo of the fit-up & completed root pass. Thanks.

 

I can't make out any problem in these photos, what is your issue?

"Everyone is entitled to their own opinions, but they are not entitled to their own facts."

 

[GemmellG]

Root pass went in really nice but when we started to weld the hot pass the wire would not fuse to the weld puddle. We tried adjusting amperage ect with no success.

 

[Ron]

That is Cupro-Nickel, not Cooper-Nickel. Cupro refers to the copper component of the alloy.

Are you pre-heating? Have you changed wire to see if bad batch?

 

[metengr]

Check your electrode connection to the work piece or table.

 

[GemmellG]

Ron No we are not preheating I did consider the wire as the issue but the root pass was perfect. Thanks.
metenr yes we did check all of the electrical connections including the programing for each pass still no success. Thanks.

 

[metengr]

Try changing your shielding gas to add 2-3% H[sub]2[/sub] to the Argon.

 

[EdStainless]

Looks like a lot of surface oxidation. Better delivery of the shield gas and more coverage would be a start.
Welding Cu/Ni is usually straightforward.

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P.E. Metallurgy, Plymouth Tube

 

[matschka]

Make sure you wire brush the root surface vigorously with a clean, not used SS wire brush. CU/NI
oxides have to be removed. That is why your 2nd pass will not adhere to the surface. It is like TIG welding Inconel, you have to vigorously wire brush the surfaces or the metal will not adhere.
Also you have to have a Hi-Level of cleanliness to get rid of any surface contaminants.

 

[weldstan]

I would suggest changing flow characteristics - nozzle size and flow rate in addition to metengr's suggestion.

 

[GemmellG]

Added 2% H2 to the Argon worked perfect all mechanical test was acceptable. Thanks to all

 

[btrueblood]

I'd want to see a sectioned weld to verify no porosity.

 

...because beauty is only skin deep.

"Everyone is entitled to their own opinions, but they are not entitled to their own facts."

 

[EdStainless]

... but ugly goes all the way through.

Applies to both welds and people.

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P.E. Metallurgy, Plymouth Tube

 

[matschka]

Hydrogen is a reducing gas, the weld surface produced by hydrogen addition to argon is in both cases very clean and without oxides.

 

[GemmellG]

Please see attached Macro showing weld profile & no defects.