2.4975

HuaNickel 2.4975 is a Fe-Ni-Cr-based precipitation-hardened deformed superalloy. The alloy is aged strengthened with a metastable γNi₃(Ti,Al) phase, and a trace amount of aluminum inhibits the conversion of γ’ to ηNi₃Ti phase. The alloy has high yield strength and lasting strength below 650 °C, good oxidation resistance below 760 °C, and stable structure for long-term use.

2.4975Chemical composition：

	Fe	C	Cr	Ni	Mo	Ti	B	AI	Mn	Si	P	S	Cu
Min	Bal	0.02	11	40	5	2.8	0.01	≤
Max		0.06	14	45	6.5	3.1	0.02	0.3	0.5	0.4	0.02	0.008	0.2

2.4975Physical properties：

Density	8.21g/cm³
Melting point	1360℃

Thermal conductivity

θ/℃	100	200	300	400	500
λ/[W/(m·℃)]	12.0	13.5	15.1	16.7	18.2
θ/℃	600	700	800	900	1000
λ/[W/(m·℃)]	19.8	21.2	22.8	24.3	25.1

Coefficient of linear expansion

θ/℃	20～100	20～200	20～300	20～400	20～500
α/(10-6℃-1)	13.5	14.0	14.4	14.9	15.1
θ/℃	20～600	20～700	20～800	20～900	——
α/(10-6℃-1)	15.2	15.5	16.0	16.5

Resilient performance

θ/℃	20	100	200	300	400
Ed/GPa	204	200	194	186	179
E/GPa	198	—		184	173
G/GPa	76	—		68	67
θ/℃	500	600	700	800	900
Ed/GPa	174	167	160	150	144
E/GPa	170	159	一	一	一
G/GPa	65	63		一

2.4975Mechanical properties：

Standard number	variety	heat treatment	Tensile properties at room temperature				room temperatureHBS	650℃Long-lasting performance
			σb/MPa	σpo.2/MPa	δ₅/%	ψ/%		σ/MPa	τ/h
			≥						≥
辽新6-0055	Hot rolled and Forged rods	systemI	1140	825	10	15	388～302	550	23
QJ/DT0160013		systemⅡ	1130	810	12	15	388～341	552	23

2.4975Alloy properties：

HuaNickel 2.4975 alloy has no notch sensitivity after standard heat treatment and long-term aging in the range of 550°C~750°C. However, when forging, if the process parameters are not selected or operated properly, long strips or flakes of harmful phase Ti₂SC and large granular boride and Ti(CN) phases can be precipitated at grain boundaries after standard heat treatment, resulting in notch sensitivity during long-lasting testing, and it is impossible to eliminate notch sensitivity through heat treatment, but can only be re-thermally processed and deformed to obtain a suitable structure. The coefficient of expansion of the alloy is close to that of ferritic hot-strength alloy steels, which allows the two materials to be joined without special regulations for thermal expansion.

2.4975Uses of alloys：

HuaNickel 2.4975 alloy has been used to make rotating parts and fasteners for aero engines and ground gas turbines, and the alloy parts have a long service life.

2.4975Process performance：

Welding process: TIG welding is possible with 2.4975 alloy welding wire

Cutting: Use carbide tools, which should have a positive inclination angle and keep the knife edge sharp. Sulfur-based oil lubrication is recommended, but must be removed before heating at high temperatures. Attention should be paid to the grinding direction in the grinding process to avoid residual tensile stress on the surface of the part, and shot peening should be carried out if it cannot be avoided.

Relevant standards：

GB/T14992、GJB 5280 、GJB 5301 、HB/Z 140 、WS9-7031、QJ/DT 0160013