What Exactly Is Haynes 230 Alloy?
Haynes 230 (UNS N06230, W.Nr. 2.4733, DIN Ni62Cr22W14Mo2) is a nickel–chromium–tungsten–molybdenum superalloy whose strength is derived entirely from solid-solution hardening — not precipitation of secondary phases. That single distinction gives it a fabricability and long-term microstructural stability profile that precipitation-hardened competitors like Inconel 718 cannot match above 700°C.
Developed by Haynes International, Inc., it has become the global benchmark for industrial applications demanding simultaneous oxidation resistance, nitriding resistance, creep strength, and thermal stability at temperatures up to 1149°C (2100°F). It performs where most other alloys begin to fail structurally.
Primary international identifier. Used in ASTM B572 (rod/bar), ASME SB-572, and AMS 5891. Sits in the N0xxxx nickel alloy series alongside Inconel 600 (N06600) and Hastelloy X (N06002). European equivalent is DIN 2.4733 (Ni62Cr22W14Mo2).
Chromium, tungsten, and molybdenum atoms substitute into the nickel FCC lattice, creating lattice distortion that impedes dislocation movement. No aging treatment is needed or possible — the alloy is supplied and used in the solution-annealed (ATA) condition.
Haynes 230 Chemical Composition (UNS N06230)
The table below lists the full compositional range per AMS 5891 / ASTM B572. Nickel is the balance element, typically 57–62%. All values are in weight percent.
| Element | Symbol | Weight % Range | Primary Function |
|---|---|---|---|
| Nickel | Ni | Balance (~47–65%) | Austenitic FCC matrix; base for all properties |
| Chromium | Cr | 20.00 – 24.00% | Cr₂O₃ oxide scale; oxidation & nitriding resistance |
| Tungsten | W | 13.00 – 15.00% | Primary solid-solution strengthener; creep resistance |
| Molybdenum | Mo | 1.00 – 3.00% | Synergistic strengthening with W & Cr |
| Iron | Fe | 3.00% max | Residual; controlled maximum |
| Cobalt | Co | 5.00% max | Residual; low Co content vs. cobalt-base alloys |
| Carbon | C | 0.05 – 0.15% | Controlled carbide strengthening; improves creep |
| Aluminum | Al | 0.20 – 0.50% | Deoxidant; minor oxide scale stability contribution |
| Lanthanum | La | 0.005 – 0.05% | Reactive element; dramatically improves oxide scale adhesion in cyclic oxidation |
| Manganese | Mn | 0.30 – 1.00% | Deoxidant; minor sulfide-former |
| Silicon | Si | 0.25 – 0.75% | Deoxidant; minor oxidation resistance contribution |
| Titanium | Ti | 0.10% max | Controlled impurity; minimal γ′ precipitation |
| Boron | B | 0.015% max | Grain boundary strengthener in trace quantities |
| Phosphorus | P | 0.030% max | Controlled impurity; embrittler if excessive |
| Sulfur | S | 0.015% max | Controlled impurity; lowers oxidation resistance if excessive |
Source: AMS 5891 Rev. C, ASTM B572. All values in weight percent.
Jiangsu Liangyi manufactures Haynes 230 (UNS N06230) forged parts to this AMS 5891 composition, with full chemistry verification on every heat via EN 10204 3.1 mill test certificates.
What Each Key Alloying Element Does
Understanding why each element is present — and at what level — is essential for correctly specifying Haynes 230 and interpreting its performance data.
Haynes 230 Mechanical Properties
Room-Temperature Minimums — AMS 5891 / ASTM B572
Elevated-Temperature Tensile Properties (ASTM E21)
| Temperature | UTS (MPa) | 0.2% YS (MPa) | Elongation (%) | Reduction of Area (%) |
|---|---|---|---|---|
| 21°C (70°F) — Room | 800 | 355 | 47 | 58 |
| 538°C (1000°F) | 720 | 275 | 46 | 57 |
| 649°C (1200°F) | 655 | 255 | 48 | 60 |
| 760°C (1400°F) | 600 | 235 | 52 | 63 |
| 871°C (1600°F) | 510 | 215 | 55 | 67 |
| 982°C (1800°F) | 275 | 180 | 68 | 73 |
| 1093°C (2000°F) | 105 | 75 | 78 | 82 |
Typical average values on solution-annealed forged bar, tested per ASTM E21. Contact Jiangsu Liangyi for heat-specific certified test data.
The 8-percentage-point gap at 649°C doesn't sound dramatic, but in 50,000+ operating hours of gas turbine service, it translates to reduced wall thickness requirements and longer component replacement intervals — both measurable economic benefits that justify the material cost premium for hot-section forgings.
Creep Rupture Strength — Stress to Cause Rupture in 1,000 Hours
| Temperature | 100-hr Rupture Stress | 1,000-hr Rupture Stress | vs. Hastelloy X at Same Temp. |
|---|---|---|---|
| 871°C (1600°F) | 165 MPa (24 KSI) | 110 MPa (16 KSI) | ~35% higher rupture strength |
| 982°C (1800°F) | 72 MPa (10.4 KSI) | 45 MPa (6.5 KSI) | ~28% higher rupture strength |
| 1093°C (2000°F) | 28 MPa (4 KSI) | 16 MPa (2.3 KSI) | ~22% higher rupture strength |
The Cr-W-Mo solid-solution triad is the mechanism behind these margins. Tungsten's large atomic radius creates maximum lattice distortion — and maximum creep resistance — in the 871–1093°C service window.
Haynes 230 Physical and Thermal Properties
These values directly control component design decisions — from wall thickness in pressure vessel engineering to differential expansion stresses in bolted turbine flanges.
| Property | At 21°C (70°F) | At 538°C (1000°F) | At 871°C (1600°F) |
|---|---|---|---|
| Density | 8.97 g/cm³ | 8.80 g/cm³ (est.) | 8.65 g/cm³ (est.) |
| Melting Range | 1301–1371°C (2375–2500°F) | ||
| Specific Heat | 397 J/kg·K | 481 J/kg·K | 536 J/kg·K |
| Thermal Conductivity | 8.9 W/m·K | 14.8 W/m·K | 19.7 W/m·K |
| Mean Thermal Expansion Coeff. (from 21°C) | — | 13.9 µm/m·°C | 15.6 µm/m·°C |
| Young's Modulus | 211 GPa | 182 GPa | 138 GPa |
| Magnetic Permeability | 1.0003 — essentially non-magnetic across full service range | ||
Haynes 230's mean thermal expansion coefficient of 13.9 µm/m·°C (21–538°C) is lower than Hastelloy X at 14.8 µm/m·°C and considerably lower than austenitic stainless steels (17–18 µm/m·°C). In a thermally cycled bolted flange assembly operating between ambient and 900°C, this lower coefficient means reduced differential expansion stresses and better long-term joint integrity — a quantifiable lifetime benefit.
Haynes 230 vs. Competing High-Temperature Alloys
The table below compares Haynes 230 against five alloys most commonly evaluated alongside it. Application parameters always govern the correct selection — this table identifies where each alloy genuinely wins and loses.
| Alloy | Max Temp. | Haynes 230 Advantage | Competitor Advantage |
|---|---|---|---|
| Hastelloy X (N06002) | ~1080°C | +35% creep rupture at 871°C; better nitriding; lower thermal expansion | Higher Mo (9%) for aqueous corrosion; wider filler availability |
| Inconel 601 (N06601) | ~1100°C | Superior nitriding resistance; higher creep strength >900°C; no σ-phase risk | Higher Al for sulfidizing; lower material cost |
| Inconel 625 (N06625) | ~980°C | Much higher strength >900°C; better nitriding resistance | Superior aqueous/chloride corrosion; better for marine service |
| Inconel 718 (N07718) | ~700°C | Can operate to 1149°C vs. 718's 700°C limit; no γ″ dissolution risk | Much higher room-temp yield (1035 MPa); ideal for cold high-stress fasteners |
| 310S Stainless (S31008) | ~1040°C | Far superior creep strength, nitriding and oxidation resistance above 900°C | Significantly lower material cost; easier to machine and weld |
Contact Jiangsu Liangyi for a free application-specific alloy selection recommendation based on your operating temperature, atmosphere, and stress profile.
Where Haynes 230 Is Used — Industry by Industry
Three properties together define Haynes 230's application space: oxidation resistance to 1149°C, industry-best nitriding resistance, and solid-solution creep strength that requires no aging treatment. Any application where all three matter simultaneously is a Haynes 230 application. Jiangsu Liangyi supplies custom Haynes 230 open die forgings and seamless rolled rings across all four industries covered below.
- →Combustion cans and transition ducts
- →Hot-section heat shields and shrouds
- →Seal rings and labyrinth rings
- →Turbine discs and guide rings
- →Thermocouple protection sheaths
- →Nitriding furnace retorts and baskets
- →Radiant tubes and burner shrouds
- →Heat-treating trays and grates
- →Recuperator internals
- →Thermocouple protection tubes
- →Catalyst grid supports
- →Heat exchanger tube sheets
- →Reformer tube headers and flanges
- →Pressure vessel nozzles
- →Bellows and expansion joints
- →Gas turbine combustor components
- →Afterburner flame holders
- →Exhaust system structural rings
- →High-temperature fasteners (>800°C)
- →Transition duct forgings
Fabrication Guidelines for Haynes 230 Forgings
One of Haynes 230's most significant but under-documented advantages is its fabricability. Because strengthening is achieved through solid-solution hardening rather than precipitation of γ′ or γ″ phases, the alloy does not require complex multi-stage aging heat treatments after fabrication — reducing downstream processing cost and risk.
Welding — Processes and Parameters
| Process | Filler Metal | Key Parameters | Best For |
|---|---|---|---|
| GTAW / TIG (preferred) | Haynes 230-W (ERNiCrWMo-1) | 100% Ar, ≥15 L/min; interpass <93°C; no preheat to 25mm | All section thicknesses; highest weld integrity |
| GMAW / MIG | Haynes 230-W wire | 75% Ar / 25% He; pulsed arc; interpass <93°C | Higher deposition on thicker sections |
| SAW (Submerged Arc) | Haynes 230-W | Low-fluoride flux; low heat input; interpass <93°C | Heavy tube sheets and large flanges |
| EBW / LBW | None (autogenous) | Vacuum environment; minimal HAZ | Precision aerospace components |
No mandatory PWHT is required for most industrial applications. For components in continuous service above 870°C, a post-weld solution anneal at 1177°C for 15–30 minutes followed by rapid quench is strongly recommended to restore full HAZ microstructure — especially for nitriding furnace internals and turbine hot-section components.
Machining — Recommended Cutting Parameters
Haynes 230 work-hardens rapidly and has low thermal conductivity — both factors that concentrate heat at the cutting edge. The parameters below, refined over 25+ years of production experience at Jiangsu Liangyi, consistently achieve Ra ≤ 1.6 µm:
| Operation | Tooling | Cutting Speed | Feed Rate | Coolant |
|---|---|---|---|---|
| Rough Turning | PVD TiAlN carbide (P20–P30) | 30–45 m/min | 0.15–0.25 mm/rev | Flood, continuous |
| Finish Turning | PVD TiAlN carbide | 45–60 m/min | 0.08–0.12 mm/rev | Flood, continuous |
| Milling | Solid carbide, positive rake | 20–35 m/min | 0.06–0.12 mm/tooth | Flood or high-pressure |
| Drilling | Solid carbide, 135° point, through-coolant | 8–15 m/min | 0.04–0.08 mm/rev | Through-tool coolant mandatory |
- AMS 5891 Rev. C — Nickel Alloy, Corrosion and Heat Resistant, 62Ni-22Cr-14W-2Mo-0.10C (Haynes Alloy 230) — SAE International
- ASTM B572-22 — Standard Specification for UNS N06002, N06230, N12160, and R30556 Alloy Rod — ASTM International, West Conshohocken, PA
- ASME Boiler and Pressure Vessel Code, Section II Part B, SB-572 — Specification for UNS N06230 Rod
- EN 10302:2008 — Creep Resisting Steels, Nickel and Cobalt Alloys — Designation 2.4733 (Ni62Cr22W14Mo2) — European Committee for Standardization (CEN)
- ASTM E21-20 — Standard Test Methods for Elevated Temperature Tension Tests of Metallic Materials — ASTM International
- Haynes International Technical Bulletin H-3009 — HAYNES 230 Alloy — Haynes International, Kokomo, Indiana, USA (property reference data)
Need Custom Haynes 230 Forgings?
Jiangsu Liangyi manufactures custom Haynes 230 (UNS N06230) open die forgings and seamless rolled rings from 30 kg to 30,000 kg. ISO 9001:2015 certified. EN 10204 3.1/3.2. Ships to 50+ countries with a 24-hour quote response.
Frequently Asked Questions About Haynes 230 Alloy
What is the maximum service temperature of Haynes 230?
Haynes 230 is rated for continuous service up to 1149°C (2100°F) in oxidizing atmospheres, where its Cr₂O₃ protective scale remains stable and adherent. For short-duration excursions, it can withstand temperatures up to approximately 1200°C before oxidation rate becomes structurally significant. This makes it the highest continuous-service-temperature alloy available in the weldable, solid-solution-strengthened nickel alloy category that can also be forged in heavy sections.
What is the difference between Haynes 230 and Hastelloy X?
Both are nickel-chromium solid-solution alloys for high-temperature service, but they differ in strengthening approach and performance ceiling. Haynes 230 uses tungsten (13–15%) as its primary solid-solution strengthener, delivering approximately 35% higher creep rupture strength at 871°C and superior nitriding resistance. Hastelloy X uses higher molybdenum (9%) and has slightly better aqueous corrosion resistance at lower temperatures. For most gas turbine hot-section forgings operating above 850°C, Haynes 230 is the superior choice.
Does Haynes 230 require heat treatment after welding?
For most industrial applications, post-weld heat treatment is not mandatory. The alloy's solid-solution-strengthened microstructure is relatively tolerant of the weld heat-affected zone. However, for components operating continuously above 870°C — particularly nitriding furnace internals, turbine combustion components, and anything subject to cyclic thermal loading — a post-weld solution anneal at 1177°C for 15–30 minutes followed by rapid quench is strongly recommended to homogenize the HAZ and restore full high-temperature mechanical properties.
What standards govern Haynes 230 forgings?
The primary standards are AMS 5891 (aerospace and industrial), ASTM B572 (rod and bar for general industrial use), and ASME SB-572 (ASME Boiler and Pressure Vessel Code equivalent). European market projects reference EN 10302 and DIN 2.4733. Oil and gas projects may additionally reference NACE MR0175 / ISO 15156 for sour service. Jiangsu Liangyi produces Haynes 230 forgings compliant with all of these standards — specify the applicable standard when submitting your RFQ.
Why does Haynes 230 have better nitriding resistance than other nickel alloys?
Nitriding resistance is primarily determined by the nature and continuity of the protective oxide scale. Haynes 230's 22% chromium content produces a dense, continuous Cr₂O₃ scale that is also an effective nitrogen barrier. The addition of lanthanum (0.005–0.05%) greatly improves scale adhesion during thermal cycling, preventing spallation events that would expose bare metal to nitriding attack. Low aluminum and titanium content — both nitride-formers — further reduces susceptibility. Together, these factors make it the industry standard for nitriding furnace retorts and baskets operating in ammonia-based atmospheres at 900–1050°C.
Is Haynes 230 magnetic?
No. Haynes 230 has a magnetic permeability of approximately 1.0003 — essentially non-magnetic. Its austenitic FCC crystal structure, stabilized by high nickel and chromium content, remains non-magnetic across its entire service range from cryogenic to 1149°C. Unlike some austenitic stainless steels, Haynes 230 does not transform to martensite under severe cold working. This makes it suitable for scientific instruments, MRI-adjacent equipment, and electronic industry furnace components requiring magnetic neutrality.
What is the recommended filler metal for welding Haynes 230?
Haynes 230-W (AWS A5.14 classification ERNiCrWMo-1) is the preferred filler metal. It is compositionally matched to the base alloy, ensuring equivalent high-temperature strength, oxidation resistance, and nitriding resistance in the weld deposit. If Haynes 230-W is unavailable, Inconel Filler Metal 625 (ERNiCrMo-3) is acceptable for applications below 900°C, but the weld zone will have lower creep strength above that temperature due to the absence of tungsten.