[MW:7186] MW: 7160- Welding of Nimonic 80A

Hi Narendra,

NIMONIC alloy 80A (UNS N07080 or W. Nr. 2.4952 &2.4631) is a wrought, age-hardenable nickel-chromium alloy, strengthened by additions of titanium, aluminum and carbon, developed for service at temperatures up to 815°C (1500°F). It’s a proprietary brand name of Special Metals.

This alloy in work hardened stage is quite difficult to weld . T.I.G. or M.I.G. (dip or pulsed transfer) is satisfactory for section thicknesses up to about 5 mm (0.2 inch). Above this thickness micro-fissuring may occur in the weld and the heat affected zone. The normal precautions for welding nickel alloys should be observed and welding should be carried out on solution treated material. Post-weld heat treatment is necessary to achieve optimum properties for thicker section.

If the extent of welding is minor then weld repair by ER-NiCrMo-3 or ERNiCr-3 would be possible beyond this as per the attached Thyssen Krupp brochure. For major repairs In order to know to what extent the materials have aged, hardness verifications around the area to be repaired should be done. Also if possible prior to welding replications of micro structure to indicate the presence of any high temperature damage, such as creep should help.

You may follow the guidance provide in this attachment to your best use.

We use this alloy in turbine as bolting; however they’re not usually weld repaired.

Thanks.

Pradip Goswami,P.Eng.

Welding & Metallurgical Engineer/Specialist

Email-pgoswami@sympatico.ca,

pgoswami@quickclic.net

From: materials-welding@googlegroups.com [mailto:materials-welding@googlegroups.com] On Behalf Of Narendra Gohil
Sent: Thursday, September 23, 2010 12:35 AM
To: materials-welding@googlegroups.com
Subject: [MW:7160] Welding of Nimonic 80A

Hi,
Need to repair "Keep Plate" which is found damaged at the tip.
Material: Nimonic 80A (2.4631;2.4952,ASTM B637)
Composition: Cr:18-21% ,Ti:1.8-2.7%,Al:1-1.8%,Co:2%,Balance:Ni
Can we repair the item ,using ERNiCrMo-3 / 2.4831?
Thanks & Regards
----------------------------
Narendra Gohil
Welding Engineer
QAFCO
Ph.00974-44228289(O)
Mo.00974-66044289
Email: ngohil@qafco.com.qa

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