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Inconel X-750 Round Bars & Rods - ASTM B637 UNS N07750 | Supplier in Mumbai, India
Nicorex Alloys is an ISO 9001 / ISO 14001 certified supplier and stockist of Inconel X-750 round bars and rods based in Mumbai, India. Alloy X-750 (UNS N07750, Werkstoff 2.4669) is a precipitation-hardenable nickel-chromium alloy (70% Ni min, 14-17% Cr) with aluminium and titanium additions, manufactured in accordance with ASTM B637 / ASME SB637.
It is based on the Ni-Cr-Fe chemistry with added Al (0.4-1.0%) and Ti (2.25-2.75%) for γ′ Ni₃ (Al, Ti) precipitation hardening. ASTM B637 defines three heat treatment types. Type 1 (service above 593°C) reaches 1103 MPa (160 ksi) tensile with a mandatory 100-hour stress-rupture qualification at 732°C. Type 2 (service up to 593°C) delivers the highest room-temperature tensile at 1172 MPa (170 ksi). Type 3 provides balanced properties at 1000 MPa (145 ksi). X-750 is non-magnetic at room temperature (Curie -134°C) and NACE MR-01-75 listed. Service spans cryogenic to 816°C (1500°F).
The diameters vary from 3 mm to 500 mm, while the bar lengths vary from 1 meter to 6 meters. The forms include round bar, hex bar, flat bar, square bar, forged bar, and spring wire or bar (to AMS 5698/5699). The conditions include solution treated, ST + stabilised + aged (Type 1), and ST + aged (Types 2 and 3). The density is 8.25 g/cm³, while the melting range is 1393-1427 °C. We are suppliers of Nickel Alloy X750 bar stock with mill test certificate 3.1 as per EN 10204.
Inconel X-750 Bar Specifications
Inconel X-750 bar specifications, dimensions, sizes, conditions, forms and other required information are provided briefly in the following table:
| Standard | ASTM B637 / ASME SB637 |
|---|---|
| AMS | 5667 (Bar, ST), 5671 (Bar), 5698/5699 (Wire Spring) |
| Diameter | 3 – 500 mm |
| Length | 1 – 6 m, cut-to-length |
| Condition | ST, ST+Stabilised+Aged (Type 1), ST+Aged (Type 2, 3) |
| Surface | Black, Bright, Polished, Turned, Ground |
| Tolerance | h9, h10, h11 per ISO 286-2 |
| Forms | Round, Hex, Flat, Square, Forged, Spring Wire/Bar |
Chemical Composition of Inconel X-750 Bar & Rod
The following table shows the Inconel X-750 chemical composition based on ASTM B637, with particular focus on the critical aluminium and titanium hardening elements.
| Nickel (Ni) | Chromium (Cr) | Iron (Fe) | Titanium (Ti) | Aluminium (Al) | Niobium + Tantalum (Nb+Ta) | Carbon (C) | Cobalt (Co) | Manganese (Mn) | Silicon (Si) | Sulphur (S) |
|---|---|---|---|---|---|---|---|---|---|---|
| 70.0 min (balance) | 14.0 – 17.0 | 5.0 – 9.0 | 2.25 – 2.75 | 0.40 – 1.00 | 0.70 – 1.20 | 0.08 max | 1.0 max | 1.0 max | 0.50 max | 0.015 max |
Al (0.4-1.0%) and Ti (2.25-2.75%) form γ′ Ni₃ (Al, Ti) precipitates, the defining feature that separates X-750 from Alloy 600. Nb+Ta (0.7-1.2%) provides secondary δ-phase strengthening at grain boundaries.
Mechanical Properties of ASTM B637 Inconel X-750 Bar
The following are the mechanical properties of Inconel X-750, with a comparison of three different heat treatment types of the alloy for specific high-temperature stress-rupture conditions.
| Property | Tensile (min) | Yield 0.2% (min) | Elongation (min) |
|---|---|---|---|
| Type 1 (>593°C) | 1103 MPa (160 ksi) | 690 MPa (100 ksi) | 16% |
| Type 2 (≤593°C) | 1172 MPa (170 ksi) | 793 MPa (115 ksi) | 18% |
| Type 3 (Balanced) | 1000 MPa (145 ksi) | 621 MPa (90 ksi) | 20% |
Type 2 values apply to bar ≤50.8 mm (2 in.) diameter. Larger bars (50.8-101.6 mm): 1103 MPa tensile, 724 MPa yield, 16% elongation. Type 1 requires a mandatory stress-rupture test: 100 hours min at 732°C / 310 MPa with 5% elongation. This grade of Inconel alloy has a mandatory stress-rupture qualification in the ASTM bar specification.
Physical Properties of Inconel X-750 Bars and Rods
The following are the physical properties of Inconel X-750, which are essential in determining the thermal expansion limits of the alloy. They include the density and melting point of the alloy.
| Property | Density | Melting Range | Elastic Modulus | Thermal Conductivity (20°C) | Thermal Expansion (20-100°C) | Electrical Resistivity (20°C) | Curie Temperature |
|---|---|---|---|---|---|---|---|
| Value | 8.25 | 1393-1427 | 213 | 12.0 | 12.6 × 10⁻⁶ | 1.22 | -193 |
| Unit | g/cm³ | °C | GPa | W/m·°C | /°C | µΩ·m | °C |
Inconel X-750 Round Bar Equivalent Grades
The following is a table showing the international equivalent designations of the UNS N07750 bar to ensure international material compliance with specific project requirements.
| UNS | Werkstoff Nr. | JIS |
|---|---|---|
| N07750 | 2.4669 | NCF 750 |
Get Inconel X-750 Round Bars at Competitive Prices
Available Forms of Inconel X-750 Bars
Nickel Alloy X-750 bar stock forms:
Inconel X-750 Round Bar
Inconel X-750 Hex Bar
Inconel X-750 Flat Bar
Inconel X-750 Forged Bar
Inconel X-750 Rectangular Bar
Inconel X-750 hollow
Inconel X-750 Rods
Precipitation Hardening & High-Temperature Creep Resistance of Inconel X-750 Bar
Type 1 (service above 593°C): Solution at 1149°C (2100°F), 2-4 hr, air cool. Stabilise at 843°C (1550°F) for 24 hr, air cool. Age at 704°C (1300°F) for 20 hr. The stabilisation step develops grain boundary carbides that improve creep-rupture resistance. Specify Type 1 for gas turbine components, nuclear reactor springs, and boiler tube hangers. The gamma-prime precipitates provide primary strengthening, while the δ-phase at grain boundaries improves notch rupture life.
Type 2 (service up to 593°C): Solution at 982°C (1800°F), 0.5 hr min, air cool. Age at 732°C (1350°F)/8 hr, furnace cool to 621°C (1150°F), total 18 hr, air cool. Delivers highest room-temperature tensile (1172 MPa). Specify Type 2 for bolting, springs, and fasteners.
Type 3 (balanced): Solution at 1079-1121°C, 1-2 hr, air cool. Age at 704°C for 20-24 hr. Specify heat treatment type on your purchase order; cost and lead time differ, especially for Type 1 with its 24-hour stabilisation step.
Machining & Welding of Inconel X-750 Bar
Inconel X-750 machining is similar to Alloy 600 in the solution-treated condition. Machine before ageing; aged material reaches 38 HRC. Use carbide tooling at 15-30 m/min with heavy steady feeds. Avoid light rubbing cuts that work-harden the surface.
Hot work at 982-1177°C. Avoid 649-870°C (low-ductility zone). Weld by GTAW, GMAW, or SMAW using INCONEL 718 filler or ERNiCr-3 for corrosion-only service. Post-weld solution anneal + full ageing restores strength. Interpass temp: 150°C max.
How to Order Inconel X-750 Round Bar & Rod
Following are some of the industries where Inconel X-750 is applicable
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Turbine blades, combustion bolting, exhaust springs, blade retaining rings (Type 1).
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Hold-down springs, CRDM components, and guide tube support pins (ASME Sections III/VIII).
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Valve springs and wellhead bolting (NACE MR-01-75).
-
Thrust chamber fasteners and cryogenic valve springs.
-
Furnace bolting and radiant tube supports.
How to Order Inconel X-750 Round Bar & Rod
Please provide the following 12 details for placing an order for Inconel X-750:
-
Product Form: Round, Hex, Flat, Square, Forged, Spring Wire/Bar
-
Diameter / Size: mm or inches
- Length: standard 1–6 m or custom cut
- Quantity: in kg, MT, or number of pieces
- Heat Treatment TYPE: Type 1, Type 2, or Type 3 – CRITICAL for X-750
- Condition: Solution Treated, or ST + Aged per specified Type
- Surface Finish: Black, Bright, Polished, Turned, Ground
- Tolerance: h9, h10, h11 or custom
- Specification: ASTM B637 / ASME SB637 / AMS 5667 / AMS 5671
- Additional Testing: PMI, UT, MPI, Stress-Rupture Test per ASTM B637, Hardness
- Test Certificates: EN 10204 3.1, 3.2
- Packaging & Delivery: standard, export-grade, wooden case
Always specify heat treatment type on your purchase order. Contact Nicorex Alloys for stock availability and price.
Frequently Asked Questions
What is the Difference between Inconel 600 and Inconel X-750?
Both share Ni-Cr-Fe chemistry (70% Ni, 14-17% Cr). Alloy 600 is solid-solution only. X-750 adds Al and Ti for γ′ precipitation hardening, reaching 1172 MPa tensile vs ~620 MPa for annealed 600, with superior creep-rupture strength at elevated temperatures.
Which Heat Treatment Type Should I Specify?
Type 1 for sustained loads above 593°C (turbines, nuclear springs). Type 2 for highest room-temperature tensile up to 593°C (bolting, fasteners). Type 3 for balanced properties.
Is Inconel X-750 Bar Suitable for Nuclear Applications?
Yes. Approved under ASME BPVC Sections III and VIII. Used for reactor hold-down springs, CRDM components, and guide tube pins. Maintains radiation-stable properties in high-purity reactor water.
Can Inconel X-750 Bar Be Cold Formed?
Yes, in the solution-treated condition. After ageing (up to 38 HRC), formability is limited. Complete all forming and machining before ageing. Spring-temper wire (AMS 5698/5699) is supplied pre-hardened for direct spring forming.