Hastelloy X: Complete Properties & Application Guide

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Overview

Hastelloy X (UNS N06002 / W.Nr. 2.4665) is a nickel-chromium-iron-molybdenum superalloy with exceptional oxidation resistance and high-temperature strength up to 1200°C. It combines good forming and welding characteristics with outstanding resistance to stress corrosion cracking in petrochemical applications.

Chemical Composition

The chemical composition of Hastelloy X is carefully controlled to achieve its unique combination of properties and performance characteristics.

Element	Min %	Max %
Nickel (Ni)	47.0	Balance
Chromium (Cr)	20.5	23.0
Iron (Fe)	17.0	20.0
Molybdenum (Mo)	8.0	10.0
Cobalt (Co)	0.50	2.50
Tungsten (W)	0.20	1.00
Carbon (C)	0.05	0.15
Silicon (Si)	—	1.0

Mechanical Properties at Room Temperature

The mechanical properties of Hastelloy X vary depending on product form and heat treatment condition. The data below represents typical values for solution-annealed material.

Property	Value
Tensile Strength	690 MPa
Yield Strength (0.2% offset)	275 MPa
Elongation in 2 inches	40%
Density	8.22 g/cm3
Melting Point	1355 °C
Max Service Temperature	1200 °C

Corrosion Resistance

Excellent oxidation resistance up to 1200°C. Good resistance to carburization and nitridation. Resistant to stress corrosion cracking in petrochemical environments. The alloy forms a protective chromium oxide scale that provides long-term protection.

Applications

The unique combination of properties makes Hastelloy X suitable for a wide range of demanding applications:

• Gas Turbines: Combustion chambers, transition pieces, and afterburner components.
• Industrial Furnaces: Furnace rolls, retorts, and high-temperature structural components.
• Petrochemical: Catalyst regeneration systems and process heaters.
• Heat Treatment: Muffles, baskets, and fixtures for high-temperature service.
• Aerospace: Jet engine tailpipes and thrust reverser components.

Available Product Forms

Hangbo Alloy Group manufactures and supplies Hastelloy X in the following product forms, conforming to ASTM, AMS, and ASME specifications:

• Round Bars: Diameters from 6 mm to 300 mm, hot-finished or cold-drawn, solution annealed.
• Seamless Tubes & Pipes: Sizes from 6 mm OD to 219 mm OD, various wall thicknesses.
• Plates & Sheets: Thicknesses from 0.5 mm to 50 mm, hot-rolled or cold-rolled.
• Forgings: Custom flanges, rings, discs, and complex shapes per customer drawing.
• Welding Wire: Diameters 0.8 mm to 5.0 mm, precision-wound coils and spools.

Related Standards

Standard	Description
ASTM B435	Plate, Sheet, and Strip
ASTM B619	Welded Pipe
ASTM B622	Seamless Pipe
ASTM B572	Bar and Rod
ASTM B366	Fittings
AMS 5536	Sheet and Strip

Elevated-Temperature Strength and Oxidation

Hastelloy X is the reference material for gas-turbine combustion cans, transition ducts and industrial furnace muffles — applications where oxidation, thermal fatigue and fabricability matter more than peak creep strength.

Temperature	Tensile (MPa)	0.2 % Yield (MPa)
20 °C	760	360
650 °C	600	270
815 °C	380	210
980 °C	150	95
Oxidation limit	continuous ≈ 1175 °C

Design to the creep and stress-rupture envelope for load-bearing parts; short-time tensile values overstate long-term capability above about 800 °C.

Fabrication, Welding and Machining Guidance

• Solution anneal at 1175 °C with rapid cool; hot work between 1180 °C and 950 °C.
• Weld by GTAW / GMAW using ERNiCrMo-2 (Hastelloy X filler) for matching oxidation resistance and strength.
• Excellent weldability for a superalloy — no preheat, no post-weld heat treatment for thin-gauge sheet fabrications.
• Ageing at 650–870 °C causes some hardening from secondary carbide precipitation; allow for reduced ductility in long service.
• Machine annealed with carbide tools and positive rake; see our machining guide for parameter starting points.

Frequently Asked Questions

Is Hastelloy X a corrosion alloy or a heat-resistant alloy?

Primarily heat-resistant. It handles oxidising and reducing furnace atmospheres up to 1175 °C, and offers moderate aqueous corrosion resistance — but for wet chemical duty, a C-type alloy such as C-276 is the better choice.

How does it compare with Inconel 625 at high temperature?

Hastelloy X has better oxidation resistance and thermal fatigue behaviour above 900 °C; Inconel 625 has higher strength and far better aqueous corrosion resistance. Combustion hardware favours X; chemical process equipment favours 625.

Can Hastelloy X be formed into complex sheet fabrications?

Yes — that is one of its main advantages. It can be readily formed and welded into combustor liners and ducting, then used without post-weld heat treatment.

What is the chemical composition of Hastelloy X?

UNS N06002 / W.Nr. 2.4665: about 47% min nickel, 20.5-23% chromium, 17-20% iron, 8-10% molybdenum, 0.5-2.5% cobalt and 0.2-1.0% tungsten.

What are its mechanical properties?

Tensile about 690 MPa, yield about 275 MPa and 40% elongation in the solution-annealed condition.

What is the maximum service temperature?

Excellent oxidation resistance up to about 1200 °C, making it a workhorse for gas-turbine and furnace components.

What applications suit Hastelloy X?

Gas-turbine combustors and afterburners, industrial furnace parts and petrochemical equipment needing stress-corrosion-cracking resistance.

Is Hastelloy X weldable?

Yes - it is readily formed and welded, which is one reason it is widely used for fabricated high-temperature components.

What standards cover Hastelloy X?

UNS N06002 / W.Nr. 2.4665, supplied to the relevant AMS and ASTM product specifications.

Contact Us for Hastelloy X

Hangbo Alloy Group maintains extensive inventory of Hastelloy X in all standard product forms. We can provide mill test certificates, third-party inspection reports (SGS, TUV), and custom processing services.

For quotations, material certifications, or technical consultation, contact our sales team or call +86 166 2109 2936. We typically respond within 10 minutes.