GH4220

HuaNickel GH4220 is a Ni-Co-Cr-based precipitation hardening deformed superalloy with a service temperature of 900°C~950°C. More aluminum and titanium elements are added to the alloy to form a γ’precipitation strengthening phase, and w(γ’) can reach more than 40%. At the same time, cobalt, chromium, tungsten and molybdenum were added for solution strengthening, and trace amounts of cerium, boron and magnesium were added for grain boundary strengthening. The alloy has high high-temperature strength and high-temperature plasticity, and has good comprehensive properties. It is suitable for manufacturing gas turbine working blades with a working temperature of 900°C~950°C.

GH4220 Chemical composition：

	Ni	Cr	Co	W	Mo	AI	Ti	V	C	Fe	B	Ce	Mg	Mn	Si
Min	Bal	9	14	5	5	3.9	2.2	0.25
Max		12	15	6.5	7	4.8	2.9	0.8	0.08	3	0.02	0.02	0.01	0.5	0.35

GH4220 Physical properties：

Density	8.36g/cm³
Melting point	330~1360℃
Magnetic properties	not

Specific heat capacity

θ/℃	20	100	200	300	400	500	600
c/[J/(kg·℃)]	471.0	472.3	473.1	473.5	473.9	475.2	476.9
θ/℃	700	800	900	1000	1100	1200	—
c/[J/(kg·℃)]	477.3	481.1	484.0	489.9	502.4	523.4

Coefficient of linear expansion

θ/℃	20～100	20～200	20～300	20～400	20～500
α/(10-*℃-1)	12.0	12.2	12.7	13.0	13.5
θ/℃	20～600	20～700	20～800	20～900	20～1000
α/(10-5℃-1)	13.9	14.6	15.2	16.1	17.7

Resilient performance

θ/℃	20	100	200	300	400	500
Ed/GPa	231	224.5	217.5	211	204	198.5
G/GPa	85.1	84.0	82.0	79.5	77.8	76.6
μ	0.35	0.34	0.33	0.32	0.31	0.28
θ/℃	600	700	800	900	950	1000
Ed/GPa	192	183	176	170	150	143
G/GPa	72.8	71.5	66.7	55.7	54.0	53.2
μ	0.32	0.28	0.32	0.52	0.39	0.34

GH4220 Mechanical properties：

Standard number	Variety	Heat treatment	Tensile properties				Room temperatureH B S	Long-lasting performance
			θ/℃	σb/MPa	δ₅/%	ψ/%		θ/℃	σ/MPa	τ/h
GJB 1953A HB 5284	Hot rolled rods	standardheat treatment	950	≥490	≥8.0	≥11.0	341～283	940 (900)	215 (275)	≥40 (≥55)

GH4220 Alloy properties：

The alloy is subjected to a special bending grain heat treatment process to control the precipitation type and morphology of the second phase on the grain boundary, so that it can form a curved grain boundary. The grain boundaries are well matched with the intragranular strength, and the brittleness of the grain boundaries is reduced, thereby significantly improving the high-temperature plasticity and long-lasting strength of the alloy.

GH4220 Uses of alloys：

HuaNickel GH4220 alloy has excellent high-temperature strength and oxidation resistance, and is widely used in aerospace, energy, chemical industry and other fields.

GH4220 Process performance：

Heat treatment process of parts:

The alloy parts are subjected to a bending grain boundary heat treatment system.

Isothermal bent crystal heat treatment: 1220°C×4h/AC to 1070°C±30°C to 1070°C furnace× 2.5h/AC+950°C× 2h/AC.

Slow bending crystal heat treatment: 1220°C×4h/ at (3~7)°C/min cooling to 1100°C/AC+1050°C×4h/AC+950°C× 2h/AC.

Heat treatment of bent crystals in the reciprocal crystal: 1220°C×4h/FC to 1050°C×4h/AC+1125°C×4h/AC+950°C×2h/AC.

Relevant standards：

GJB 1953A、HB5284、GH220、HB/Z140