MAR-M918
Mar-M918 is a Ni-Cr-Co based solid solution reinforced deformation superalloy. Its composition is characterized by 20%Co, 20%Cr, 20%W, and adding trace element lanthanum to strengthen grain boundaries. The alloy has high strength and creep resistance at 1000 ℃, and still has good second strength at 1100-1200 ℃. The alloy has excellent oxidation resistance and good cold forming and welding properties.
Equivalent Grades
Trademark | GB | GOST | ASTM | UNS | DIN | W.Nr. | NF | BS | JIS | SS |
MAR-M918 | GH3170 | – | MAR-M918 | – | – | – | – | – | – | – |
Chemical Composition, %
Alloy | C | Si | Mn | P | S | Cr | Ni | Co | W | Al | La | B | Zr |
MAR-M918 | ≤0.06 | ≤0.80 | ≤0.50 | ≤0.013 | ≤0.013 | 18.0-22.0 | Bal | 15.0-22.0 | 17.0-21.0 | ≤0.50 | 0.10 | ≤0.005 | 0.1-0.2 |
Typical Physical and Mechanical Properties (RT, Annealed+Aged)
Density, g/cm3 | Melting Point, ℃ | Tensile Strength, MPa | Yield Strength, MPa | ELongation, % | Hardness, HRB |
9.34 | 1395-1425 | 855 | 427 | 45 | – |
Available Products and Specifications
Rod, Bar, Wire and Forgings | – |
Plate, Sheet and Strip | – |
Pipe and Tube | – |
Welding Product | – |
Others | – |
Features
- High strength and creep resistance at 1000 ℃
- Good second strength at 1100-1200 ℃
- Excellent oxidation resistance and good cold forming and welding properties
Applications
Alloy have been used in the manufacture of aeroengine power combustor adjusting plate parts, recommended for aeroengine combustor and other high-temperature components, and as nozzle material for rocket engines. The μ phase precipitates out of the alloy after long-term aging at 900-1000 ℃, which reduces the plasticity of the alloy at room temperature, but it can still meet the requirements of use.