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HAYNES® Alloys

Welding and Fabrication

ULTIMET® alloy is very amenable to the Gas Metal Arc (GMA/MIG), Gas Tungsten Arc (GTA/TIG), and Shielded Metal Arc (SMA/Stick) welding processes. Matching filler metals (i.e. spools, reels, coils, and cut straight lengths of solid wire, and coated electrodes) are available for these processes. Guidelines for weld surfacing with ULTIMET® alloy are detailed in a separate Haynes International document "ULTIMET® Weld Overlay Guidelines". Other arc processes have been used to weld ULTIMET® alloy; for more information on consumable availability for these other processes, please consult Haynes International.

Wrought products of ULTIMET® alloy are supplied in the Mill Annealed (MA) condition, unless otherwise specified. This solution annealing procedure has been designed to optimize the alloy’s corrosion resistance and ductility. Following all hot forming operations, the material should be re-annealed, to restore optimum properties. The alloy should also be re-annealed after any cold forming operations that result in an outer fiber elongation of 7% or more. The annealing temperature for ULTIMET® alloy is 1177°C (2150°F), and water quenching is advised (rapid air cooling is feasible with structures thinner than 10 mm (0.375 in). A hold time at the annealing temperature of 10 to 30 minutes is recommended, depending on the thickness of the structure (thicker structures need the full 30 minutes).

ULTIMET® alloy can be hot worked and cold-worked. However, it is very strong, and work-hardens rapidly during cold-working. The alloy may therefore require frequent, intermediate anneals, if cold-working is employed. Please consult Haynes International for more details.

While cold-work does not usually affect the resistance of ULTIMET® alloy to general corrosion, and to chloride-induced pitting and crevice attack, it can affect resistance to stress corrosion cracking. For optimum corrosion performance, therefore, the re-annealing of cold-worked parts (following an outer fiber elongation of 7% or more) is important.

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