Inconel X-750 (UNS N07750)

Inconel X-750 (also specified as UNS N07750 / Werkstoff No. 2.4669) is a precipitation-hardening nickel-chromium alloy strengthened by titanium, aluminium and niobium. It develops very high strength through age hardening, while retaining good corrosion resistance, oxidation resistance and properties up to about 700 °C. It is especially widely used for high-temperature springs, bolts / fasteners, turbine components and fasteners in gas-turbine and nuclear service.

Overview

• Category: Precipitation-hardening (PH) nickel-based superalloy (Ni-Cr-Ti-Al-Nb)
• Standards: ASTM B637, AMS 5608, AMS 5667, UNS N07750, DIN/EN 2.4669
• Available forms: Round bar / rod, wire, plate, sheet, pipe & tube, forgings, and custom profiles to order (particularly widely used for springs and fasteners).

Chemical Composition (wt%)

Physical Properties

Mechanical Properties

Good high-temperature strength and creep resistance are retained up to approximately 650 °C.

Fabrication & Welding

• Hot working: 1000–1150 °C with uniform heating; air cool or water cool after working.
• Cold working: Good cold-formability (cold rolling, cold drawing), but with a relatively high work-hardening rate.
• Welding: Readily welded by GTAW (TIG), electron-beam welding and similar processes. Clean the surface before welding; post-weld age-hardening is recommended.

Heat Treatment

• Solution treatment: Heat to 980–1010 °C, then water-quench or rapidly air-cool.
• First ageing: Hold at 720 °C for 8 hours, then furnace-cool to 620 °C.
• Second ageing: Hold at 620 °C for 8 hours, then air-cool, to precipitate the gamma-prime strengthening phase and develop final high strength and hardness.

Key Features

• High strength below 650 °C, with excellent tensile, yield and fatigue performance;
• Good corrosion and oxidation resistance in a wide range of environments;
• Precipitation-hardening response allows strength to be greatly increased by heat treatment;
• Good fabrication and welding behaviour for a wide range of components.

Corrosion Resistance

• Good resistance to seawater, neutral salt solutions and nitric acid;
• Strong resistance to pitting and crevice corrosion;
• Resists high-temperature sulfur-bearing and other complex furnace environments to a useful extent.

Typical Applications

• Aerospace: turbine discs, blades, casings and other high-temperature engine parts;
• Power generation: critical components of gas turbines and nuclear reactors;
• Petrochemical: high-temperature, high-pressure corrosion-resistant piping and reaction vessels;
• Automotive: critical components of high-performance engines;
• General: high-temperature springs, bolts, fasteners and sealing elements.

For detailed datasheets, mill certificates (EN 10204 3.1) or inquiries on specific sizes and tolerances, please contact our sales & engineering team.