Incoloy 945 (UNS N09945) is an age-hardenable austenitic nickel-iron-chromium alloy containing 45 to 55 percent nickel and 19.5 to 23 percent chromium, with additions of molybdenum, copper, niobium, titanium and aluminium. Niobium, titanium and aluminium precipitate gamma prime Ni3(Ti,Nb,Al) and gamma double prime Ni3(Nb,Ti,Al) phases during age hardening. These give the alloy a minimum 0.2 percent yield strength of 125 ksi (862 MPa) while it keeps its resistance to sulfide stress cracking and chloride stress corrosion cracking. The alloy was developed for high-strength sour oil and gas service.

Incoloy 945 Forgings (UNS N09945): Rings, Flanges, Bars, Discs

Q: What heat treatment is used for Incoloy 945 forgings?

Solution anneal at 1010 to 1066 C (1850 to 1950 F) for 0.5 to 4 hours and water quench, then double age. The first age is 704 to 732 C (1300 to 1350 F) for 6 to 8 hours, followed by furnace cooling at 26 to 56 C per hour to 607 to 635 C (1125 to 1175 F), a hold of 6 to 8 hours, then air cooling. Rough machine before ageing and finish after final heat treatment for best dimensional control.

Q: What is the density of Incoloy 945?

8.2 g/cm3, equal to 0.296 lb/in3. To estimate forging weight, a ring of outside diameter D, bore d and height H in millimetres weighs approximately 3.1416 x (D squared minus d squared) / 4 x H x 8.2 / 1,000,000 kilograms.

1.0What is Incoloy 945?

Incoloy 945 is an austenitic nickel-iron-chromium alloy made precipitation-hardenable by its content of niobium, titanium and aluminium. It is used for wellhead and downhole parts that need a high yield strength together with resistance to hot chloride brine containing hydrogen sulfide.

The main alloying elements each have a defined role. Nickel, 45 to 55 percent, gives resistance to chloride-induced stress corrosion cracking, and together with molybdenum and copper it gives resistance to general corrosion in reducing media. Chromium, 19.5 to 23 percent, forms the protective oxide that resists oxidising environments. Molybdenum, 3 to 4 percent, resists localised attack, meaning pitting and crevice corrosion, in chloride-bearing brines. Niobium, titanium and aluminium react during age hardening to precipitate sub-micron Ni₃(Ti,Nb,Al) gamma prime and Ni₃(Nb,Ti,Al) gamma double prime particles. These particles are distributed uniformly in the matrix and are the source of the alloy's strength.

Names this grade is ordered under

Incoloy 945, trade name of Special Metals Corporation
UNS N09945, Unified Numbering System designation
Alloy 945 or 945 alloy, generic industry usage
Incoloy 945X, UNS N09946, the higher-strength grade with the same composition limits
No EN or Werkstoff number exists for this grade. Specify Incoloy 945 / UNS N09945 on the purchase order.

2.0Chemical composition

Limiting composition in weight percent. Incoloy 945 and 945X have the same composition limits. The two grades differ in strength, not in chemistry.

Table 2.1. Limiting chemical composition of Incoloy 945 and 945X (UNS N09945 / N09946), wt %
Element	Minimum	Maximum	Function in the alloy
Nickel (Ni)	45.0	55.0	Chloride SCC resistance, austenite stability
Chromium (Cr)	19.5	23.0	Passive oxide film, resistance in oxidising media
Iron (Fe)	Balance		Base element, keeps alloy cost below Ni-base grades
Molybdenum (Mo)	3.0	4.0	Pitting and crevice corrosion resistance
Niobium (Nb)	2.5	4.5	Gamma double prime precipitation
Copper (Cu)	1.5	3.0	Resistance in reducing acids
Titanium (Ti)	0.5	2.5	Gamma prime precipitation
Aluminium (Al)	0.01	0.70	Gamma prime precipitation, deoxidation
Carbon (C)	0.005	0.040	Held low to limit grain-boundary carbides
Manganese (Mn)	–	1.0	Residual
Silicon (Si)	–	0.50	Residual
Sulfur (S)	–	0.030	Impurity, restricted for hot workability
Phosphorus (P)	–	0.030	Impurity
Limits per the Special Metals Corporation INCOLOY alloys 945 / 945X bulletin. Product analysis tolerances apply per ASTM B880 when ordered to ASTM B637.

Jiangnan melts this grade by EAF plus VOD plus ESR: electric arc melting, vacuum oxygen decarburisation, then electroslag remelting. The route holds sulfur, phosphorus and non-metallic inclusions low enough for sour-service hardware and gives the ingot soundness needed for large open-die forgings.

3.0Mechanical properties

Incoloy 945 is supplied in several strength grades. State the condition on the enquiry, because the condition decides which property set applies.

3.1 Limiting properties, annealed and aged

Table 3.1. Minimum properties of annealed and aged alloy 945, 945X and 925 at room temperature
Alloy	Producer spec	Yield, 0.2% min	Tensile min	Elong. min	R of A min	Impact min	Hardness
945	HA 119	125 ksi / 862 MPa	150 ksi / 1034 MPa	18%	25%	40 ft·lb / 54 J	32–42 HRC
945X	HA 123	140 ksi / 965 MPa	165 ksi / 1138 MPa	18%	25%	40 ft·lb / 54 J	32–42 HRC
925	HA 46	110 ksi / 759 MPa	140 ksi / 965 MPa	18%	25%	35 ft·lb / 47 J	26–38 HRC

3.2 Limiting properties, cold worked and direct aged shaft grade

Table 3.2. Minimum properties of annealed, cold drawn and aged shaft-grade bar
Alloy	Producer spec	Yield, 0.2% min	Tensile min	Elong. min	R of A min	Hardness
945	HA 121	165 ksi / 1138 MPa	180 ksi / 1241 MPa	15%	20%	38–46 HRC
945X	HA 122	210 ksi / 1448 MPa	220 ksi / 1517 MPa	12%	18%	40–48 HRC
Shaft grades exceed the 40 HRC hardness cap that many sour-service specifications impose. Confirm the applicable NACE MR0175 / ISO 15156-3 or API 6ACRA hardness limit before selecting a shaft grade for wetted service.

3.3 Typical properties by bar diameter

Section size affects properties in open-die forgings, because larger sections cool and age differently. Typical measured values for annealed and aged round bar:

Table 3.3. Typical measured properties, annealed and aged round bar. Impact tested at −75 F (−59 C)
Alloy	Diameter	Yield 0.2%	Tensile	Elong.	R of A	Impact	Hardness
945	25 mm / 1 in	920 MPa / 133 ksi	1194 MPa / 173 ksi	27.8%	48.0%	103 J	40 HRC
945	152 mm / 6 in	972 MPa / 141 ksi	1214 MPa / 176 ksi	22.0%	34.6%	75 J	42 HRC
945	356 mm / 14 in	967 MPa / 140 ksi	1167 MPa / 169 ksi	26.6%	30.7%	105 J	39 HRC
945X	152 mm / 6 in	1025 MPa / 149 ksi	1238 MPa / 180 ksi	27.1%	50.1%	102 J	40 HRC
Typical values from commercially produced material, not guaranteed minima. Order to the Table 3.1 or Table 3.2 limits.

Note on units. SI values are converted at 1 ksi = 6.895 MPa. Where a published table and its conversion disagree, the inch-pound value governs, per ASTM B637.

4.0Physical properties

Table 4.1. Physical properties of Incoloy 945, room temperature unless stated
Property	Metric	Imperial
Density	8.2 g/cm³	0.296 lb/in³
Melting range	1270–1377 °C	2317–2510 °F
Young's modulus	195–201 GPa	28.3–29.1 × 10&sup6; psi
Shear modulus, 23 °C	74 GPa	10.8 × 10³ ksi
Poisson's ratio	0.31
Electrical resistivity	1.10 µΩ·m	663 Ω·cmil/ft
Magnetic permeability at 15.9 kA/m (200 Oe)	1.003, effectively non-magnetic
Thermal conductivity, 23 °C	10.9 W/m·°C	75.9 BTU·in/ft²·h·°F
Specific heat, 23 °C	445 J/kg·°C	0.106 BTU/lb·°F
Mean thermal expansion, 25–93 °C	14.19 × 10⁻⁶ /°C	7.88 × 10⁻⁶ /°F
Mean thermal expansion, 25–538 °C	15.39 × 10⁻⁶ /°C	8.55 × 10⁻⁶ /°F

Weight estimating. At 8.2 g/cm³, a forged ring of outside diameter D, bore d and height H, all in mm, weighs about π(D² − d²)/4 × H × 8.2 / 1 000 000 kg. A 600 mm OD by 400 mm bore by 200 mm ring is therefore about 258 kg finished, before machining allowance.

5.0Corrosion and sour-service qualification

Alloy 945 was developed and qualified for hot production environments carrying high hydrogen sulfide and high chloride content, where alloy 825 does not have the strength and 13Cr does not have the corrosion resistance.

5.1 NACE MR0175 / ISO 15156-3 qualification

Table 5.1. C-ring test conditions used to qualify alloy 945, NACE TM0177 method C, stressed to 100% of actual yield
Severity level	H₂S	CO₂	Chloride	Temperature	Result
Level VII	3500 kPa / 508 psia	3500 kPa / 508 psia	25 wt% NaCl, 150 000 mg/L Cl	205 °C / 401 °F	No failure, 90 days
Level VI-450 °F	3500 kPa / 508 psia	3500 kPa / 508 psia	20 wt% NaCl, 120 000 mg/L Cl	232 °C / 450 °F	No failure, 90 days

Sulfide stress cracking and galvanically induced hydrogen stress cracking tests to NACE TM0177 method A, at 90 percent of actual yield in NACE solution A, also ran 30 days without failure. API 6A lists UNS N09945 and N09946 for any equipment or component up to 205 °C (401 °F) within the stated environmental envelope.

Hydrogen-induced stress cracking

API 6ACRA notes that some age-hardened nickel-base alloys meeting NACE MR0175 and API 6ACRA can still be susceptible to HISC, for example where components are galvanically coupled to a more active material or exposed to seawater under cathodic protection. Subsea designers should carry out their own HISC assessment. Grade qualification alone does not replace it.

5.2 Pitting and stress corrosion cracking, comparative

Table 5.2. Localised corrosion and chloride SCC performance against alloy 925 and 304 stainless steel
Test	Alloy 945	Alloy 925	304 stainless
Critical pitting temperature, ASTM G48	50 °C	35 °C	Not reported
Boiling 25% NaCl, pH 1.5, 108 °C, ASTM G123	No cracks at 720 h	No cracks at 720 h	Cracked at 22 h
Boiling 45% MgCl₂, 155 °C, ASTM G36	Failure at 142 h	Failure at 70 h	Failure at 13 h
ASTM G36 boiling magnesium chloride is a deliberately severe screening test and does not represent production environments.

6.0Incoloy 945 forged products we make

All items below are produced to customer drawing by open-die forging or ring rolling, then heat treated, ultrasonically tested and machined as required. There is no fixed size catalogue. Send a drawing or the dimensions.

Rings and rolled rings

Seamless rolled rings, forged rings, retainer and seat rings, bearing races.

Flanges

Weld neck, slip-on, blind and ring-type-joint flanges, forged to drawing rather than to a stock dimension table.

Bars and blocks

Round, square, flat, stepped and hollow bars. Forged blocks for machining valve bodies.

Discs and blanks

Forged discs, discs with bore, tube sheets and cover plates.

Shafts

Straight, stepped and eccentric shafts, pump shafting, spindles, plunger stock.

Sleeves and bushings

Forged sleeves, bushings, hollow forgings, nozzles and pipe sections.

Valve and wellhead parts

Valve bodies, seat rings, stems, blocks, hangers and Christmas-tree components.

Machined parts

Rough machined with allowance, or finish machined to print with a dimensional report.

Inspection and documentation

Ultrasonic testing to EN 10228-3, SEP 1921 or ASTM A388, acceptance class per your order
Mechanical testing, covering tensile, hardness and Charpy impact including low-temperature testing
Certification to EN 10204 3.1, or 3.2 with third-party witness such as TUV, SGS, BV, LR or your nominated inspector
Additional NDT, covering dye penetrant, magnetic particle where applicable, and PMI verification of grade
Traceability, with heat number marking and a material test report referencing the melt

7.0Forging, heat treatment and machining

7.1 Hot and cold working

The hot working range is 930 to 1150 °C (1700 to 2100 °F), and hot working behaviour is close to that of alloy 718. The alloy accepts up to 40 percent cold work. Its work-hardening rate is similar to Monel K-500, so machining practice developed for stainless steel needs adjusting: the material hardens quickly ahead of a dull tool.

7.2 Heat treatment

Table 7.1. Recommended heat treatment cycle
Step	Temperature	Time	Cooling
Solution anneal	1010–1066 °C / 1850–1950 °F	0.5–4 h	Water quench
First age	704–732 °C / 1300–1350 °F	6–8 h	Furnace cool 26–56 °C per hour
Second age	607–635 °C / 1125–1175 °F	6–8 h	Air cool
The alloy can be annealed from 954 °C, but 1010 to 1066 °C gives the best combination of grain size and properties. Solution and ageing treatments are run in sequence on the same charge.

7.3 Machining

Machinability is good in either the solution annealed or the aged condition. Use rigid tooling with positive rake angles and methods that limit work hardening. Rough machine before age hardening and finish after final heat treatment, which also helps control distortion. Machinability is comparable to stainless grades 302, 303, 410, 420, 430 and 430F, at a higher strength level.

7.4 Welding

Weld by GTAW or pulsed GMAW, using matching Incoloy filler metal 945 or INCO-WELD filler metal 725NDUR. For pulsed GMAW in spray-arc transfer, keep current below about 185 A on standard power sources. Submerged arc and shielded metal arc welding are not recommended. Cross-weld properties are higher with filler metal 945, and GTAW joints made with it failed in the base metal rather than the weld. Re-anneal and age after welding.

8.0Applications

Alloy 945 is specified where a part has to be strong, hardness-limited for sour service, and resistant to hot chloride brine at the same time.

Downhole and surface gas-well hardware, including tubulars, hangers, landing nipples, tool joints and packers
Wellhead and Christmas-tree components, including forged blocks and bodies, valve bodies, seat rings, stems and bonnets
Subsea and deepwater production systems, including connectors, sleeves and mandrels, subject to a HISC assessment
Pump shafting for chemical, plunger and injection pumps, using the cold worked and direct aged shaft grades
Fasteners, where studs and nuts need both strength and corrosion resistance
High-strength piping and pressure equipment, including forged flanges, tube sheets, nozzles and heat-exchanger components
Process equipment, including columns, towers, separators and preheaters handling chloride-bearing or reducing media

9.0Incoloy 945 compared with neighbouring grades

Table 9.1. Selecting between age-hardened oilfield alloys
Alloy	UNS	Min yield, annealed and aged	Hardness band	CPT, ASTM G48	Where it fits
Incoloy 825	N08825	Not age hardened	Not applicable	Not reported	Corrosion resistance without high strength
Incoloy 925	N09925	110 ksi / 759 MPa	26–38 HRC	35 °C	Moderate strength sour service
Incoloy 945	N09945	125 ksi / 862 MPa	32–42 HRC	50 °C	Higher strength and better pitting resistance than 925, level VII sour service
Incoloy 945X	N09946	140 ksi / 965 MPa	32–42 HRC	50 °C	Same corrosion performance, highest annealed and aged strength in this family
Inconel 718	N07718	Per API 6ACRA	40 HRC max per 6ACRA	Not reported	Widely available and economical, lower corrosion limits than 945
Inconel 725	N07725	Per API 6ACRA	Per spec	Not reported	High corrosion resistance. Special Metals reports 945X as the stronger of the two
Per the Special Metals bulletin, the strength of alloy 945X exceeds that of alloys 718, 725 and 925. Confirm limits against the specification and revision named in your purchase order.

10.0Standards, specifications and approvals

Table 10.1. Documents governing Incoloy 945 forgings
Document	Covers
UNS N09945 / N09946	Grade designation for alloy 945 and 945X
ASTM B637	Precipitation-hardening and cold worked nickel alloy bars, forgings and forging stock
API 6ACRA	Age-hardened nickel-base alloys for oil and gas drilling and production equipment, including microstructure acceptance criteria for N09945
API 6A	Wellhead and Christmas-tree equipment. Lists N09945 and N09946 service limits, PSL 1 to 4
NACE MR0175 / ISO 15156-3	Sour-service qualification, level VII and level VI-450 °F
NACE TM0177	SSC and GHSC test methods used for qualification
Special Metals HA 119, HA 123, HA 121, HA 122	Producer property limits for 945, 945X and shaft-grade bar
EN 10204 3.1 / 3.2	Inspection certificate type
EN 10228-3, SEP 1921, ASTM A388	Ultrasonic examination of forgings

Note on ASTM B564

ASTM B564, Nickel Alloy Forgings, is often quoted for this grade. Its scope does not list UNS N09945. For alloy 945 forgings the correct references are ASTM B637, together with API 6ACRA and NACE MR0175 / ISO 15156-3. If your specification names B564 for N09945, raise it with your material engineer before the order is placed.

11.0How to order Incoloy 945 forgings

Send the following to sales@steelforgepieces.com and we will quote the same working day.

Table 11.1. Information needed for a quotation
Item	Example
Grade and strength condition	Incoloy 945 (N09945), annealed and aged, 125 ksi min yield, or 945X
Drawing or dimensions	PDF, DWG or STEP, or OD by bore by height with machining allowance
Machining state	As forged, rough machined with allowance, or finish machined to print
Quantity and schedule	Prototype single piece, or annual quantity with call-off
Specification and revision	ASTM B637, API 6ACRA, NACE MR0175 / ISO 15156-3, client spec number
Testing and NDT	UT class to EN 10228-3, Charpy at −46 °C, hardness survey, PMI
Certification	EN 10204 3.1, or 3.2 with named third party
Delivery terms and port	FOB Shanghai, CIF Houston, DAP address

Start an enquiry by email Or call +86 189 2135 9659

12.0Frequently asked questions

What is Incoloy 945?

Incoloy 945 (UNS N09945) is an age-hardenable austenitic nickel-iron-chromium alloy containing 45 to 55 percent nickel and 19.5 to 23 percent chromium, with additions of molybdenum, copper, niobium, titanium and aluminium. Niobium, titanium and aluminium precipitate gamma prime Ni₃(Ti,Nb,Al) and gamma double prime Ni₃(Nb,Ti,Al) phases during age hardening. These give the alloy a minimum 0.2 percent yield strength of 125 ksi (862 MPa) while it keeps its resistance to sulfide stress cracking and chloride stress corrosion cracking. The alloy was developed for high-strength sour oil and gas service.

What is the UNS number for Incoloy 945?

Incoloy 945 is UNS N09945. The higher-strength variant, Incoloy 945X, is UNS N09946. There is no equivalent EN or Werkstoff number, so purchase orders should specify Incoloy 945 / UNS N09945 or Incoloy 945X / UNS N09946 directly.

Is Incoloy 945 approved for sour service?

Yes. Incoloy 945 is qualified under NACE MR0175 / ISO 15156-3 up to level VII, and to level VI at 450 °F (232 °C). Level VII qualification was demonstrated by C-ring tests to NACE TM0177 method C at 205 °C in 3500 kPa H₂S, 3500 kPa CO₂ and 25 wt percent NaCl (150 000 mg/L chloride) stressed to 100 percent of yield, with no failures after 90 days. API 6A lists UNS N09945 for any equipment or component up to 205 °C (401 °F).

What is the difference between Incoloy 945 and Incoloy 945X?

The two grades have the same chemical composition limits and differ in strength. Annealed and aged Incoloy 945 has a minimum 0.2 percent yield strength of 125 ksi (862 MPa) and minimum tensile strength of 150 ksi (1034 MPa). Incoloy 945X is the high-strength grade at 140 ksi (965 MPa) minimum yield and 165 ksi (1138 MPa) minimum tensile. Both fall in a 32 to 42 HRC hardness band. Cold worked and direct aged shaft grades reach 165 ksi minimum yield for 945 and 210 ksi for 945X.

What is the difference between Incoloy 945 and Incoloy 925?

Incoloy 945 is the stronger and more pitting-resistant of the two. Annealed and aged alloy 945 has a minimum yield strength of 125 ksi (862 MPa) against 110 ksi (759 MPa) for alloy 925. Its critical pitting temperature in the ASTM G48 ferric chloride test is 50 °C against 35 °C for alloy 925. The hardness bands also differ: 32 to 42 HRC for alloy 945 and 26 to 38 HRC for alloy 925.

Which standards and specifications apply to Incoloy 945 forgings?

UNS N09945 is covered by ASTM B637 for precipitation-hardening nickel alloy bars, forgings and forging stock, by API 6ACRA for age-hardened nickel-base alloys in drilling and production equipment, and by NACE MR0175 / ISO 15156-3 for sour service. Producer property limits are defined in Special Metals specifications HA 119 for alloy 945, HA 123 for 945X, and HA 121 and HA 122 for shaft-grade bar. ASTM B564 is sometimes quoted for this grade, but its scope does not list UNS N09945.

What heat treatment is used for Incoloy 945 forgings?

Solution anneal at 1010 to 1066 °C (1850 to 1950 °F) for 0.5 to 4 hours and water quench, then double age. The first age is 704 to 732 °C (1300 to 1350 °F) for 6 to 8 hours, followed by furnace cooling at 26 to 56 °C per hour to 607 to 635 °C (1125 to 1175 °F), a hold of 6 to 8 hours, then air cooling. Rough machine before ageing and finish after final heat treatment for best dimensional control.

Can Incoloy 945 be welded?

Yes, by gas tungsten arc welding (GTAW) and pulsed gas metal arc welding (P-GMAW), using matching Incoloy filler metal 945 or INCO-WELD filler metal 725NDUR. Submerged arc welding and shielded metal arc welding are not recommended. Filler metal 945 GTAW joints give higher cross-weld properties than 725NDUR deposits. Weldments should be re-annealed and aged after welding.

What is the density of Incoloy 945?

8.2 g/cm³, equal to 0.296 lb/in³. To estimate forging weight, a ring of outside diameter D, bore d and height H in millimetres weighs about π(D² − d²)/4 × H × 8.2 / 1 000 000 kilograms.

Is Incoloy 945 magnetic?

No, it is effectively non-magnetic. Magnetic permeability is 1.003 at 200 oersteds (15.9 kA/m), because the alloy has a stable austenitic structure.

Which forged shapes can Jiangyin Jiangnan Metal supply in Incoloy 945?

Jiangyin Jiangnan Metal Co., Ltd. produces Incoloy 945 forged rings and seamless rolled rings, forged flanges, round and stepped bars, discs and blanks, shafts and eccentric shafts, sleeves and bushings, tube sheets, hollow forgings, and forged blocks for valve and wellhead components, all made to customer drawing.

How do I request a quotation for Incoloy 945 forgings?

Email a drawing or dimensions to sales@steelforgepieces.com or call +86 189 2135 9659. State the grade and strength condition (945 or 945X), whether the part is rough or finish machined, the quantity, the applicable specification such as ASTM B637 or API 6ACRA, the required NDT such as ultrasonic testing to EN 10228-3 or ASTM A388, and whether EN 10204 3.1 or 3.2 certification is needed. Quotations are normally issued within 24 hours.

13.0Supplier

Jiangyin Jiangnan Metal Co., Ltd. is an open-die forging factory in Jiangyin, Jiangsu Province, China. The company forges parts to customer drawing in carbon steel, alloy steel, tool steel, stainless steel and nickel alloys, including Incoloy 945 (UNS N09945) and Incoloy 945X (UNS N09946). Parts are supplied heat treated, ultrasonically tested and certified to EN 10204 3.1 or 3.2.

Company: Jiangyin Jiangnan Metal Co., Ltd.
Factory address: No.1 Chengxiqiao Road, Zhouzhuang Town, Jiangyin City, Jiangsu Province, China
Telephone and WhatsApp: +86 189 2135 9659
Email: sales@steelforgepieces.com
Website: steelforgepieces.com
Capability: Open-die forging, ring rolling, heat treatment, machining, NDT

Quoting this datasheet

The technical data on this page may be quoted with attribution. Suggested citation:

Jiangyin Jiangnan Metal Co., Ltd. "Incoloy 945 Forgings (UNS N09945): composition, mechanical properties and sour-service data." steelforgepieces.com/Nickel-Alloy/Incoloy-945.html, updated 19 August 2026. Supplier contact: sales@steelforgepieces.com, +86 189 2135 9659.

Property data compiled from the Special Metals Corporation INCOLOY alloys 945 / 945X bulletin, ASTM B637, API 6ACRA, API 6A and NACE MR0175 / ISO 15156-3. Values are for guidance. The specification and revision named in your purchase order governs.

Published 20 May 2013. Revised 19 August 2026 by the technical department, Jiangyin Jiangnan Metal Co., Ltd.