Incoloy 907 Introduction

Overview

As a leading supplier & manufacturer in China, AEETHER supply cost-effective Incoloy 907 Products.

INCOLOY® alloy 907 (UNS N19907) is a nickel-iron-cobalt alloy having high strength along with a low coefficient of thermal expansion. The alloy is strengthened by age-hardening heat treatments.

The combination of low expansion and high strength makes INCOLOY alloy 907 useful for gasturbine components. The low expansion enables closer control of clearances and tolerances for greater fuel efficiency. The high strength makes possible higher strength-to-density ratios for lower weight in aircraft engines. For those reasons, INCOLOY alloy 907 is used for gas-turbine seals, shafts, casings, and other structural parts.

The properties of INCOLOY alloy 907 are attractive for other applications including instrumentation, glass-to-metal sealing, ceramicmolding dies, and electricity generation.

Mechanical Properties

In the age-hardened condition, INCOLOY® alloy 907 has high mechanical properties. For example, when heat treated for optimum tensile properties, INCOLOY alloy 907 has yield and tensile strengths similar to those of INCONEL® alloy 718.

INCOLOY alloy 907 normally receives one of two heat treatments, depending on whether the strength requirements of the application are tensile limited or rupture limited. For tensile-limited applications, the age-hardening treatment is: 1325°F (720°C)/8 h, furnace cool at 100°F (55°C)/h to 1150°F (620°C)/8 h, air cool.

For rupture-limited applications, the treatment is: 1425°F (775°C)/12 h, furnace cool at 100°F (55°C)/h to 1150°F (620°C)/8 h, air cool.

Before either age-hardening treatment, the alloy is given a solution anneal of 1800°F (980°C)/1 h, air cool. Heat treatment of INCOLOY alloy 907 is covered by a U.S. patent.

Corrosion Resistance

INCOLOY alloy 907 contains no chromium because the presence of that element would increase thermal expansion. The absence of chromium, however, makes the alloy more susceptible to oxidation in high-temperature atmospheres. In some applications, INCOLOY alloy 907 may require a protective coating to prevent excessive oxidation. Figure 3 compares INCOLOY alloy 907 with INCONEL® alloy 718 (19% chromium) in a cyclic oxidation test at 1200°F (650°C).

A characteristic of INCOLOY alloy 907 is that unlike other alloys of comparable strength, it has good resistance to embrittlement in high-pressure hydrogen.

Physical Properties

Density		g/cm3	8.33
		lb/in.3	0.301
Melting Range		°F	2440 - 2550
		°C	1335 - 1400
Curie Temperature		°F	750 - 850
		°C	400 - 455
Specific Heat		Btu/lb-°F	0.103
		J/kg-°C	431
Thermal Conductivity at 200°F (93°C)		Btu-in/ft2-h-°F	108.5
		W/m-°C	15.6
Electrical Resistivity		ohm circ mil/ft	419
		μΩ-m	0.697
Young’s Modulus (70°F)		103 ksi	23.9
		GPa	165
Shear Modulus (70°F)		103 ksi	8.8
		GPa	61
Poisson’s Ratio			0.36

Mechanical Properties

Temperature		Yield Strength (0.2% Offset)		Tensile Strength		Elongation	Reduction of Area
°F	°C	ksi	MPa	ksi	MPa	%	%
Age hardened for tensile-limited applications
70	20	162.5	1120	194.5	1341	15.0	36.5
800	427	142.4	982	168.3	1160	14.9	40.7
1000	538	137.5	948	164.3	1133	13.8	42.2
1200	649	126.2	870	151.2	1043	10.2	26.8
1400	760	82.0	565	93.9	647	20.9	52.0
Age hardened for rupture-limited applications
70	20	128.5	886	175.5	1210	16.0	25.0
800	427	105.1	725	154.8	1067	16.6	32.6
1000	538	105.5	727	150.2	1036	15.8	38.0
1200	649	98.7	681	136.5	941	19.8	42.2
1400	760	63.5	438	77.4	534	31.5	70.2