Incoloy 907 / 909(Ni - Co - Nb)

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1. Introduce

– Ni – Co – Nb alloys with high Co content

– Alloys designed to overcome the limitations of Invar alloys

(Addition of Co to Ni – Fe alloy → increase in curie temperature → decrease in high temperature coefficient of thermal expansion of the alloy)

– No Cr added, resulting in low coefficient of thermal expansion and susceptibility to oxidation in high temperature environments

– Difference between Incoloy 907 and Incoloy 909 : Si content (Incoloy 907 has about 0.25% less Si than 909)

– Incoloy 909 : Alloy designed to overcome the limitations of Incoloy 907 (Si added to improve notch rupture resistance properties)

– UNS N19907 / UNS N19909

* UNS

Abbreviation of Unified Numbering Systems for Metals and Alloys
Unified numbering system for metals and alloys
A representative number that is compatible with metals and alloys defined in many material – related codes such as ASTM, AISI, ASME, AWS, etc.

* N : Nickel and nickel alloys

* 907 / 909 : N19907 / N19909 : 19XXX : Fe & Co (Precipitation – Hardenable)
(The last two or three digits of the six UNS numbers are used as the alloy model number)

* Incoloy

– An alloy containing less than 50% Ni, with a higher content of Fe compared to Inconel (Ni – Cr – (Mo))

* Invar alloy limitations : loss of low expansion properties in temperature range above 200°C

* Curie temperature : temperature at which magnetic materials lose their ferromagnetic properties and are replaced by paramagnetism

* Coefficient of Thermal Expansion : The length stretched in a specific direction when the temperature of the material increases by 1℃

→ Low coefficient of thermal expansion : increases power, fuel efficiency, thermal fatigue and thermal shock resistance

2. Property

– High strength, low thermal expansion coefficient

Element	Impact
Ni	Provides strength, toughness, corrosion resistance, heat resistance
Co	Provides high temperature strength, high temperature hardness
Nb	Provide strength
Si	Provides notch rupture resistance

[Incoloy 907 / 909 Chemical Composition (%)]

	Ni	Fe	Al	Ti
907	35.00 ~ 40.00	36.45 ~ 47.33	Max. 0.20	1.30 ~ 1.80
909	35.00 ~ 40.00	36.35 ~ 47.15	Max. 0.15	1.30 ~ 1.80

	Si	Co	Nb
907	0.07 ~ 0.35	12.00 ~ 16.00	4.30 ~ 5.20
909	0.25 ~ 0.50	12.00 ~ 16.00	4.30 ~ 5.20

[Incoloy 907 / 909 Mechanical Properties]

	Tensile Strength (MPa)	Yield Strength (MPa)	Elongation (%)
907	Min. 1341	Min. 1120	Min. 15.00
909	Min. 1276	Min. 1034	Min. 15.00

[Incoloy 907 / 909 Physical Properties]

	Density (g/㎤)	Melting Range (℃)	Specific Heat (0-100℃) / (J/Kg℃)	Curie Temperture (℃)
907	8.33	1335 ~ 1400	431	400 ~ 455
909	8.19	1395 ~ 1430	427	400 ~ 455

3. Standard & Specification

– Specification : UNS N19907 / UNS N19909

	ASTM	SAE
Incoloy 907	B366, B408	AMS 5541, AMS 5542, AMS 5544, AMS 5548
Incoloy 909	–	AMS 5884, AMS 5893, AMS 5892

4. Available Form

– Plate & Sheet & Strip

– Coil

– Forgings

5. Application & Product

– Aerospace, Marine, Power generation, chemical

Application	Product
Aerospace	Turbine disks, Turbine blades, Combustion chamber casings
Marine	Drilling rigs, Seawater desalination plants, Submarine hulls
Power generation	Turbine blades, Boiler tubes, Heat exchangers
Chemical	Reactors, Heat exchangers, Piping