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

MAR-M918

≤0.06

≤0.80

≤0.50

≤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.