NIMONIC ® alloy 263 (UNS N07263/W. Nr. 2.4650), an air melted nickel-base alloy, was developed by Rolls-Royce (1971) Ltd. To provide a sheet material which could be readily fabricated and would offer improved ductility in welded assemblies to replace NIMONIC alloy 80A.

It was designed as sheet material to meet specific design criteria in terms of proof stress and creep strength. It is now available in all standard forms.

The welding techniques for this alloy are similar to those in common use for other age-hardenable nickel-base alloys. During salvage welding operations, a preweld heat-treatment is not necessary on age-hardened assemblies but a subsequent age-hardening treatment is desirable after all salvage welding is completed. Material will age in service if temperatures are above 750°C.