Multimet N155,Multimet Tube,UNS R30155

Multimet N155,Multimet Wire,UNS R30155

Multimet N155 (Multimet Wire, UNS R30155) - Introduction with Composition, Properties, Applications and Product Forms

Multimet N155, commercially known as Multimet and designated by UNS R30155, is a cobalt-based superalloy celebrated for its exceptional high-temperature strength, oxidation resistance, and thermal fatigue resistance. This alloy is specifically engineered to thrive in extreme thermal environments, making it a vital material in aerospace, energy, and industrial applications where components are exposed to elevated temperatures, cyclic loading, and harsh atmospheres. It is available in a comprehensive range of forms to meet diverse industrial needs, including Bar (Round bar, Flat bar), Ribbon, Wire, Rods, Tube, Pipe, Foil, Plate, Sheet, Strip, and Forging Stock. Multimet Wire, in particular, is valued for its uniform mechanical properties, high-temperature stability, and precision, making it ideal for welding, thermal spray coatings, and intricate components in gas turbine engines and high-heat industrial systems. Below is a detailed overview of its chemical composition, key properties, practical applications, and available product forms.

Chemical Composition

The precisely balanced chemical composition of Multimet N155 (Multimet, UNS R30155) is the foundation of its exceptional high-temperature performance and corrosion resistance. The typical composition (by weight) is as follows:

Cobalt (Co): 29-31% (the primary element, forming the alloy’s matrix and providing high-temperature stability)

Chromium (Cr): 20-22% (enhances oxidation and corrosion resistance, forming a protective oxide layer at elevated temperatures)

Nickel (Ni): 20-22% (improves ductility and toughness, complementing cobalt’s high-temperature properties)

Tungsten (W): 13-15% (contributes to high-temperature strength through solid-solution strengthening and carbide formation)

Molybdenum (Mo): 3.0-4.0% (strengthens the alloy matrix and enhances resistance to creep)

Iron (Fe): 3.0-4.0% (aids in workability and balances the alloy’s mechanical properties)

Carbon (C): 0.10-0.15% (forms carbides with tungsten, chromium, and molybdenum, improving grain boundary strength)

Silicon (Si): ≤ 1.0% (aids in deoxidation during manufacturing and enhances oxidation resistance)

Manganese (Mn): ≤ 1.0% (enhances hot workability and controls sulfur content)

Boron (B): 0.005-0.015% (aids in grain boundary strengthening, reducing creep rupture)

This carefully engineered composition, with its blend of cobalt, chromium, nickel, and refractory metals, delivers the alloy’s signature high-temperature strength, oxidation resistance, and thermal fatigue resistance—key to its performance in extreme thermal environments.

Key Properties

Multimet N155 (Multimet Wire, UNS R30155) and its various forms exhibit extraordinary properties that make them indispensable in high-temperature applications:

Mechanical Properties (solution-annealed condition):

Tensile strength: 1000-1200 MPa (145,000-174,000 psi) at room temperature

Yield strength (0.2% offset): 550-650 MPa (79,800-94,300 psi) at room temperature

Elongation (in 50 mm): 15-25% (good ductility for forming and fabrication)

Reduction of area: 20-30% (excellent toughness, enabling complex shaping)

Hardness: 30-35 HRC (Rockwell hardness, reflecting high strength)

High-Temperature Properties:

Continuous service temperature: Up to 1100°C (2012°F) (maintains strength and oxidation resistance)

Creep resistance: Excellent resistance to creep deformation at temperatures up to 980°C (1800°F), with a 1000-hour creep rupture strength of ~180 MPa (26,100 psi) at 870°C (1600°F)

Oxidation resistance: Superior resistance to oxidation and scaling at temperatures up to 1150°C (2102°F), due to a dense chromium oxide layer

Thermal fatigue resistance: Withstands repeated thermal cycling without cracking, critical for components in gas turbines and high-heat industrial systems

Corrosion Resistance:

General corrosion: Excellent resistance to atmospheric corrosion, high-temperature gases, and combustion by-products

Oxidation and sulfidation: Resists oxidation in air and sulfidation in sulfur-containing environments up to high temperatures

Chemical resistance: Withstands exposure to fuels, lubricants, and industrial chemicals, making it suitable for harsh industrial environments

Physical Properties:

Density: 8.6-8.8 g/cm³ (0.311-0.318 lb/in³)

Thermal conductivity: 19-21 W/(m·K) at 20°C (68°F); increases to 28-31 W/(m·K) at 1000°C (1832°F)

Coefficient of thermal expansion: 13-15 μm/(m·K) (20-1000°C)

Modulus of elasticity: 230-240 GPa (33,400-34,800 ksi) at room temperature; decreases to ~170 GPa (24,600 ksi) at 1000°C

Melting point: 1350-1400°C (2462-2552°F)

Product Forms

Multimet N155 (Multimet, UNS R30155) is manufactured in a diverse range of forms to accommodate specialized high-temperature applications:

Bar: Available as Round bar (diameters from 10 mm to 200 mm) and Flat bar (thickness 5 mm to 100 mm, width 20 mm to 500 mm), ideal for machining into turbine components, valve stems, and high-temperature fasteners.

Ribbon: Thin, flat strips (thickness 0.1 mm to 1 mm, width 5 mm to 100 mm) used in thermal spray coatings, electrical heating elements, and high-temperature seals.

Wire: Multimet Wire (diameters 0.5 mm to 6 mm) is widely used for welding (TIG, MIG) and thermal spray applications, as well as for manufacturing precision springs and thermocouple sheaths in high-temperature environments.

Rods: Solid cylindrical rods (diameters 3 mm to 50 mm) used for gas tungsten arc welding (GTAW) and gas metal arc welding (GMAW) of high-temperature components.

Tube and Pipe: Hollow forms (outer diameter 6 mm to 100 mm, wall thickness 1 mm to 10 mm) for high-temperature fluid handling, such as in rocket engine coolant systems and industrial furnaces.

Foil: Ultra-thin sheets (thickness 0.02 mm to 0.1 mm) used in high-temperature gaskets, heat shields, and thin coatings for thermal management.

Plate and Sheet: Flat forms (plate: thickness 3 mm to 50 mm; sheet: 0.3 mm to 3 mm) for fabricating turbine blades, combustion liners, and heat-resistant structural components.

Strip: Narrow, flat strips (thickness 0.1 mm to 2 mm, width 3 mm to 50 mm) for precision components such as turbine seals, electrical contacts, and heat exchanger fins.

Forging Stock: Billets and ingots for hot forging into complex shapes, such as gas turbine disks, rocket engine nozzles, and high-pressure valve bodies.

Applications

The exceptional high-temperature strength, oxidation resistance, and thermal fatigue resistance of Multimet N155 (Multimet Wire, UNS R30155) across its various forms make it a critical material in industries requiring reliable performance under extreme thermal conditions:

Aerospace and Aviation:

Gas turbine engines: Turbine blades, vanes, and combustion liners (from plate, bar, and forging stock) for jet engines, withstanding high temperatures and centrifugal forces.

Aerospace fasteners: High-temperature bolts, nuts, and studs (from bar and wire) securing components in jet engines and aircraft structures.

Rocket propulsion systems: Nozzle components, heat shields, and fuel lines (from tube, forging stock, and sheet) resisting extreme heat from rocket fuel combustion.

Energy and Power Generation:

Gas turbines: Hot-section components (from plate, bar, and forging stock) for industrial gas turbines, enduring high temperatures and cyclic loading.

Waste-to-energy plants: Combustion liners and heat recovery components (from sheet and plate) withstanding corrosive and high-temperature flue gases.

Nuclear power: Heat exchanger tubes and structural components (from tube and plate) resisting radiation and high-temperature coolants.

Industrial and Manufacturing:

High-temperature furnaces: Heating elements, furnace liners, and thermocouple sheaths (from wire, tube, and foil) operating in air or inert atmospheres.

Chemical processing: Reactor components, catalyst support grids, and heat exchangers (from plate, tube, and bar) withstanding aggressive chemicals at elevated temperatures.

Metallurgical processing: Rolls, fixtures, and tooling (from bar and plate) for hot metal forming and heat treatment applications.

Defense and Military:

Missile systems: Propulsion components, guidance system parts, and heat shields (from forging stock, tube, and sheet) withstanding extreme thermal and mechanical stress.

Military aircraft engines: Critical components (from bar, plate, and forging stock) requiring high strength and durability in harsh operational environments.

Specialized Applications by Form:

Wire: Welding filler metal for joining high-temperature components, thermal spray coatings, and thermocouple wires.

Bar/Plate: Turbine disks, blades, and structural components in gas turbines and aerospace systems.

Tube/Pipe: High-temperature fluid transport in aerospace and industrial systems, such as coolant lines and fuel injectors.

Strip/Ribbon: Seals, gaskets, and heating elements in high-temperature machinery and furnaces.

In summary, Multimet N155 (Multimet Wire, UNS R30155) — available in forms from Bar and Wire to Plate and Forging Stock — delivers exceptional high-temperature strength, oxidation resistance, and thermal fatigue resistance. Its diverse product forms enable tailored solutions across aerospace, energy, industrial, and defense sectors, establishing it as a critical material in applications requiring reliable performance under extreme thermal conditions.

Packing of Standard Packing:

 Typical bulk packaging includes palletized plastic 5 gallon/25 kg. pails, fiber and steel drums to 1 ton super sacks in full container (FCL) or truck load (T/L) quantities. Research and sample quantities and hygroscopic, oxidizing or other air sensitive materials may be packaged under argon or vacuum. Solutions are packaged in polypropylene, plastic or glass jars up to palletized 1334 gallon liquid totes Special package is available on request.