Nickel Alloys

Austenitic Ni-Fe-Cr alloy specifically developed for sulfuric acid resistance. Nb-stabilized against sensitization. Cu addition gives outstanding resistance to H2SO4 at all concentrations up to 80%. Used for sulfuric acid piping, heat exchangers, mixing tanks, pickling equipment, and pharmaceutical processing.

Super-austenitic stainless steel (Fe-31Ni-27Cr-3.5Mo-1Cu) with ultra-low carbon. Exceptional resistance to sulfuric acid, phosphoric acid, and chloride stress corrosion cracking. Solution-annealed: Rm 500–750 MPa, Rp0.2 ≥220 MPa, A ≥35%. Density 8.0 g/cm³, PREN ~39–47. UNS N08028, ASTM B709/B668. Applications: phosphoric acid evaporators, sulfuric acid piping, oil/gas sour service (NACE MR0175), seawater heat exchangers, nuclear fuel reprocessing. Alleima trade name Sanicro 28.

Super austenitic Ni-Cr-Mo alloy — Ni 31%, Cr 27%, Mo 6.5%. Between 926 (Ni 25%) and C-276 (Ni 57%) in the alloy hierarchy. PREN >50. Outstanding resistance to pitting, crevice corrosion, and SCC in highly aggressive chloride and acid environments. Used for FGD scrubbers, phosphoric acid production, sulfuric acid condensers, and seawater systems. Trade name: Nicrofer 3127 hMo (VDM).

Iron-nickel-chromium alloy (Fe-32Ni-21Cr) with controlled carbon (0.05–0.10%) and grain size for optimized creep-rupture strength above 600°C. Solution-annealed: Rm ≥450 MPa, Rp0.2 ≥170 MPa, A ≥30%. Density 7.94 g/cm³, E-Modul 196 GPa. Excellent resistance to carburization, oxidation, and nitriding to 1100°C. UNS N08810, ASTM B407/B408/B409. Applications: ethylene cracking tubes, reformer furnace tubes, heat exchangers, nuclear steam generators, chemical reactors. Variant 800HT (N08811/1.4959) has tighter Al+Ti control for even higher creep strength.

Improved version of Hastelloy C-276 with better resistance to oxidizing media and higher chromium. Considered the most versatile Ni-Cr-Mo alloy for chemical processing. Resists both oxidizing and reducing acids, chlorides, and mixed media. Used for flue gas desulfurization, pharmaceutical, and universal chemical processing.

The most versatile corrosion-resistant alloy available. Ni-Mo-Cr-W composition resists both oxidizing and reducing environments. Outstanding resistance to pitting, stress corrosion cracking, and wet chlorine gas. Used in chemical processing, flue gas desulfurization, pulp & paper, and waste treatment.

Nickel-chromium-iron-molybdenum solid-solution superalloy — exceptional combination of oxidation resistance, fabricability, and high-temperature strength. NOT age-hardenable (solid-solution only). Oxidation-resistant to 1200°C, good ductility after 16000h at 650-870°C. Outstanding formability and weldability for a superalloy. Used for gas turbine combustor cans, transition ducts, afterburners, furnace hardware, and petrochemical process equipment.

Nickel-chromium-tungsten alloy — THE combustor can material for gas turbines. Outstanding oxidation resistance to 1149°C for prolonged exposure. Excellent long-term thermal stability (no sigma/mu phase after 16000h at 649-870°C). Lower thermal expansion than most high-temp alloys. Lanthanum addition improves oxide scale adherence. Used for gas turbine combustion cans, transition ducts, furnace retorts, and catalyst grids in nitric acid production.

Nickel-iron-chromium alloy with Mo, Cu, and Ti additions. Excellent resistance to both reducing and oxidizing acids, stress corrosion cracking, and pitting. Cost-effective alternative to pure Ni alloys. Used in chemical processing, pollution control, oil/gas recovery, and acid production.

Nickel-chromium-iron alloy — the standard engineering material for combined heat and corrosion resistance. Not precipitation hardenable. Virtually immune to chloride-ion stress corrosion cracking. Service from cryogenic to 1095°C. Used for furnace components, nuclear steam generators, chemical plant equipment, and food processing.

Nickel-chromium-iron alloy with aluminum for outstanding high-temperature oxidation resistance up to 1200°C. The Al forms a protective oxide scale resistant to spalling under cyclic thermal conditions. Better oxidation resistance than Inconel 600 (which lacks Al). Used for furnace hardware (baskets, trays, fixtures), radiant tubes, thermocouple protection tubes, catalyst support grids, and thermal reactors in automotive exhaust systems.

Nickel-chromium-cobalt-molybdenum alloy for the highest temperature service of any Inconel — continuous use to 1000°C+. Unique combination of high-temperature strength, oxidation resistance, and carburization resistance. 12% Co for solid-solution strengthening at extreme temperature. ASME Code Case N-47-28 for nuclear service to 950°C. Used for gas turbine combustors, petrochemical reformer tubes, catalyst grid supports, and next-generation nuclear heat exchangers (VHTR).

Nickel-chromium-molybdenum-niobium superalloy. Solid-solution strengthened (no precipitation hardening required). Outstanding corrosion resistance from cryogenic to 982°C. Used for jet engine exhaust systems, marine components, chemical processing, flare stacks, and nuclear applications.

High-chromium (27-31%) nickel alloy — THE nuclear PWR steam generator tube material, replacing Inconel 600 due to superior SCC resistance. Ni 58% min + Cr 30% = exceptional resistance to oxidizing media, nitric acid, and high-temperature atmospheres. Also used for coal gasification, radioactive waste processing, and sulfuric/hydrofluoric acid environments.

Precipitation-hardenable nickel-iron-chromium alloy (Ni-40Fe-16Cr-3Nb-1.7Ti). Similar properties to Inconel 718 but significantly better machinability and fabricability due to delayed hardening response. Solution-annealed: Rm ~757 MPa, Rp0.2 ~383 MPa. Precipitation-hardened: Rm ~1334 MPa, Rp0.2 ~1112 MPa, A ~24%. Excellent resistance to postweld strain-age cracking. Max service temperature ~705°C. Applications: gas turbine discs, compressor blades, turbine shafts, fasteners, ring forgings for power generation and aerospace.

THE most widely used aerospace superalloy. Precipitation-hardened Ni-Cr-Fe alloy strengthened by gamma-prime and gamma-double-prime phases (Nb). Unique slow aging kinetics allow welding without cracking. UTS >1275 MPa aged. Used for gas turbine discs, jet engine components, rocket motors, cryogenic tanks, and oil/gas downhole tools. Service to 700°C.

Age-hardenable Ni-Cr-Fe superalloy for high-temperature spring and fastener applications. Strengthened by gamma-prime precipitation (Al+Ti). Oxidation and corrosion resistant to ~700°C service. Used for gas turbine springs, rocket engine thrust chambers, nuclear reactor components, and high-temp fasteners.

Nickel-copper alloy with excellent resistance to seawater, hydrofluoric acid, and alkaline environments. One of the few alloys resistant to HF acid at all concentrations. Used for marine engineering, chemical processing, oil refinery piping, and valve/pump components.

Age-hardenable version of Monel 400. Al and Ti additions enable precipitation hardening to double the strength of Monel 400. Retains excellent seawater and HF acid resistance. Used for pump shafts, impellers, doctor blades, oil well tools, and marine fasteners.

Nickel-chromium age-hardenable alloy with Ti + Al for gamma-prime strengthening. Developed originally for gas turbine blades. Good creep resistance to ~700°C. Used for exhaust valves, springs at elevated temperatures, nuclear engineering fasteners, and gas turbine components. ≈ UNS N07080.

Precipitation-hardened Ni-Cr-Co superalloy — Ti+Al for gamma-prime strengthening. Creep-resistant to 920°C (higher than Nimonic 80A at ~815°C). Co 15-21% for solid-solution strengthening. Used for gas turbine blades, turbine discs, exhaust re-heaters, high-temp springs, and motorsport engine valves. Also hot-working tools.

Nickel-based gamma-prime strengthened superalloy — THE turbine disc material. Excellent creep-rupture strength up to 650°C (rotating) and 870°C (static). Developed 1950s by Pratt & Whitney. Triple-aged (solution + stabilize + precipitation) for peak properties. Superior to Inconel 718 above 650°C. Used for compressor and rotor discs, shafts, spacers, seals, rings, casings, and fasteners in gas turbine engines.