Key takeaways
Bottom line: For a new, efficiency-driven hot section that must run hotter or thinner, Haynes® 230 (UNS N06230) is the stronger choice — it holds roughly 50% more stress-rupture strength than Hastelloy® X at 925 °C (based on Haynes International's published data). For a proven, cost- or fabrication-sensitive part where the drawing already calls out UNS N06002, Hastelloy® X remains the practical pick.
- Same family: both are solid-solution nickel superalloys sharing about 70% of their composition; neither is age-hardened.
- Strength: Haynes 230 wins at temperature — tungsten strengthening plus stable carbides give ~50% higher stress-rupture strength at 925 °C (1700 °F).
- Temperature: Haynes 230 sustains oxidising service to ~1150 °C and resists grain growth to ~1204 °C; Hastelloy X softens and coarsens sooner.
- Practicality: Hastelloy X is easier to form/weld/repair, more widely stocked and lower in cost.
- Decider: the qualifying specification usually settles it — never substitute without re-qualifying the part.
At a glance: Hastelloy X vs. Haynes 230
A side-by-side summary of the two alloys across the properties that matter for combustor and hot-section forgings.
| Property | Hastelloy X (N06002) | Haynes 230 (N06230) |
|---|---|---|
| Alloy system | Ni-Cr-Fe-Mo | Ni-Cr-W-Mo (+La) |
| Primary strengthener | Molybdenum + iron | Tungsten + stable carbides |
| Stress-rupture at 925 °C | Baseline | ≈ 50% higher |
| Sustained oxidation limit | ~1090 °C useful strength | ~1150 °C (2100 °F) |
| Grain-growth resistance | Coarsens sooner | Stable to ~1204 °C |
| Thermal expansion | Higher | Lower (less distortion) |
| Fabricability / weld repair | Excellent | Good |
| Availability | Very wide | Narrower |
| Relative material cost | Lower | Higher (W, La) |
| Best for | Proven / budget / easy-fab parts | New, hotter, thinner, long-life parts |
Same family, two different backbones
On paper, Hastelloy X and Haynes 230 look like cousins. Both are nickel-base, chromium-rich, solid-solution-strengthened alloys made to resist oxidation while carrying load in the hottest non-rotating parts of a gas turbine. Their compositions overlap by roughly 70%. The difference that matters lives in three elements — molybdenum, tungsten and iron — and in how each alloy stiffens the nickel matrix against creep.
Hastelloy X leans on molybdenum (~9%) plus iron (~18%) for a cost-effective, highly fabricable solid solution. Haynes 230 swaps most of that iron out and trades much of the molybdenum for tungsten (~14%) — a heavier, slower-diffusing atom that pins the lattice more firmly at temperature. Haynes 230 also carries a small, deliberate addition of lanthanum, which anchors the protective chromia scale so it resists spalling under thermal cycling.
| Element | Hastelloy X (N06002) | Haynes 230 (N06230) |
|---|---|---|
| Nickel (Ni) | Balance | Balance |
| Chromium (Cr) | 20.5–23.0 | ~22.0 |
| Tungsten (W) | 0.2–1.0 | ~14.0 |
| Molybdenum (Mo) | 8.0–10.0 | ~2.0 |
| Iron (Fe) | 17.0–20.0 | 3.0 max |
| Cobalt (Co) | 0.5–2.5 | 5.0 max |
| Carbon (C) | 0.05–0.15 | ~0.10 |
| Lanthanum (La) | — | ~0.02 |
Neither alloy is age-hardened; both stay ductile and weldable because they rely on solid-solution strengthening and stable carbides rather than a gamma-prime precipitate. That is why both have been combustor-section staples for so long — and why the real contest is how well each holds those properties over thousands of hours in the fire.
The numbers that decide it
When you reach for one of these alloys, you are usually optimising the same trade-off: keep enough load-carrying strength at red heat to avoid buckling and creep, while resisting oxidation and thermal fatigue for the life of the part. On the strength axis, Haynes 230 wins clearly.
Haynes 230 also expands less as it heats. Its lower coefficient of thermal expansion means smaller dimensional swings and lower thermal stress across a start-stop cycle, protecting tight clearances and extending fatigue life in complex fabrications. Hastelloy X, with more iron in solution, moves a little more with temperature — rarely a problem in itself, but a factor when parts must hold close tolerances through thousands of cycles.
The honest summary: Haynes 230 is metallurgically superior in most high-temperature measures. Hastelloy X earns its place through cost, availability, fabrication ease and an enormous body of qualified service history.
Where Hastelloy X still shows an edge is in reducing and carburising atmospheres and in stress-corrosion resistance for certain petrochemical furnace duty — environments outside the pure oxidising combustor case. So the two alloys are not perfectly interchangeable even when both would "fit" a temperature target.
What this means where the flame actually is
Combustor liners, transition ducts, flame holders, splash plates, nozzle and vane assemblies, and the surrounding ducting all share one demand: hold shape and strength in an oxidising gas stream that swings from cold-start to full-fire many times over. This is the arena both alloys were designed for, and it is where Haynes 230's strength margin turns into real design freedom.
Because 230 keeps more strength at temperature, a designer can specify a thinner liner gauge for the same creep life — less mass to heat, faster thermal response, better fuel efficiency. Its grain and carbide stability also mean fewer surprises after long dwell at temperature: less coarsening, less embrittling phase formation, and a scale that stays put through cycling. Hastelloy X remains entirely capable here, and countless engines still run it reliably; the question is usually whether the extra 230 performance is worth its cost on a new design versus a proven one.
For rotating or pressure-boundary hardware — turbine disks, high-pressure rings, reactor and vessel forgings — the logic shifts again, and precipitation-hardened grades such as Inconel® 718 or high-temperature solid-solution alloys like Inconel® 617 often join the comparison. For the static hot section, though, the Hastelloy X versus Haynes 230 pairing is the classic decision.
Which alloy for your part?
Reduce it to intent. If you are protecting an existing, qualified design and want the easiest path to a sound forging, Hastelloy X is usually right. If you are designing a new hot section around efficiency, weight or a higher temperature ceiling, Haynes 230 gives you room the older alloy cannot.
Reach for Hastelloy X
UNS N06002 · AMS 5754 / AMS 5536
- The drawing or spec already calls out N06002
- Budget and lead time are priorities
- Complex forming, welding or field weld-repair is expected
- Reducing or carburising furnace atmospheres are involved
- A long qualified service record must be preserved
Reach for Haynes 230
UNS N06230 · AMS 5891 / ASTM B564
- New design targeting higher efficiency or thinner gauges
- Sustained metal temperatures approaching 1100–1150 °C
- Severe thermal cycling where low expansion helps
- Long-life parts where grain and phase stability matter
- Weight reduction justifies the higher material cost
One rule sits above all of these: the qualifying specification wins. Combustor and hot-section hardware is almost always tied to an OEM material and process spec, and a substitution — even a "better" one — has to be re-qualified. Confirm the drawing, the mechanical-property requirements and the heat-treatment before you switch a part from one alloy to the other.
Frequently asked questions
Is Haynes 230 a drop-in replacement for Hastelloy X?
Not automatically. The alloys share roughly 70% of their composition and both are solid-solution combustor materials, but they are qualified to different specifications and diverge on long high-temperature exposure. Haynes 230 usually enables thinner, longer-life hot-section parts; Hastelloy X is often retained where a proven, already-qualified service history exists. Always confirm the drawing specification, mechanical requirements and heat-treatment before substituting.
Which alloy is stronger at combustor temperatures?
Haynes 230, by a clear margin. Near 925 °C (1700 °F) its stress-rupture strength can be about 50% higher than Hastelloy X, thanks to tungsten solid-solution strengthening and very stable primary carbides that resist grain growth. That headroom is what lets designers move to thinner, more efficient gauges.
When is Hastelloy X still the better choice?
Where a long qualified service record must be preserved, where cost and lead time matter, where easier forming, welding and weld-repair are priorities, or where the component drawing explicitly specifies UNS N06002 to AMS 5754. Hastelloy X is also generally more available and lower in cost, and holds an edge in some reducing and carburising furnace atmospheres.
What is the maximum service temperature of Hastelloy X and Haynes 230?
Both resist oxidation to roughly 1200 °C, but Haynes 230 retains useful strength much closer to that ceiling. Haynes 230 tolerates sustained oxidising service to about 1150 °C (2100 °F) and resists grain growth even at 1204 °C (2200 °F) for short exposures, whereas Hastelloy X loses strength and coarsens sooner at those temperatures.
Can Jiangsu Liangyi supply both alloys as forgings and rolled rings?
Yes. We produce both Hastelloy X (UNS N06002) and Haynes 230 (UNS N06230) as open-die forgings and seamless rolled rings, VIM/ESR or VIM/VAR melted. Each shipment includes a mill test report and a manufacturer-issued EN 10204 3.1 material certificate; independent EN 10204 3.2 certificates (SGS, BV or TÜV) are available on request. ISO 9001 is the only third-party certification we currently hold.
Sources & references
- Haynes International — HAYNES® 230® alloy for Gas Turbine & Aerospace Applications (tech brief): stress-rupture advantage over Hastelloy X at 1700 °F and sustained oxidation resistance to 2100 °F.
- Haynes International — HAYNES® 230® alloy product page: stable primary carbides and grain-growth resistance to 2200 °F, low thermal expansion.
- ASTM International — ASTM B572 and related nickel-alloy material specifications: composition and mechanical-property requirements for UNS N06002.
- Published UNS grade data for UNS N06002 and UNS N06230 (nominal compositions and property ranges).
Figures are indicative and provided for engineering guidance. For design or purchase, verify against the governing specification and a current mill test report.
Liu Mingru — Senior Metallurgical Engineer, Jiangsu Liangyi Co., Limited. Educated at Zhejiang University, with over 10 years in nickel-based superalloy forging, melting and metallographic quality control. Property comparisons here are drawn from published grade data for UNS N06002 and UNS N06230 and the sources listed above, and are provided for engineering guidance only. Last reviewed 4 August 2026.
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