Overview: What Makes HAYNES HR-160 (UNS N12160) Unique?
HAYNES HR-160 — formally designated UNS N12160 under ASTM/SAE and W.Nr. 2.4886 under DIN/EN — is a solid-solution-strengthened nickel-cobalt-chromium-silicon superalloy engineered specifically for the most aggressive high-temperature corrosive environments in modern industrial operations.
The alloy’s defining feature is its silicon addition of 2.4–3.0 wt%, which generates a continuous, self-repairing SiO² sub-scale beneath the primary Cr²O³ outer oxide layer. This dual-layer diffusion barrier physically blocks sulfur and chlorine penetration to the base metal — a protection mechanism absent in virtually all other commercially available wrought nickel alloys including Inconel 625 and Hastelloy X.
The result: HAYNES HR-160 achieves continuous service temperatures up to 1204 °C (2200 °F) in corrosive gas environments, and field data from waste incineration facilities consistently shows service life extensions greater than 10× versus conventional Ni-Cr alloys under identical operating conditions. For engineers sourcing precision UNS N12160 forged parts, understanding the alloy’s underlying chemistry is critical to correct specification and long service life.
About this guide’s author: Jiangsu Liangyi Co., Limited is an ISO 9001:2015 certified manufacturer with over 25 years of experience in superalloy forging, including Alloy HR-160 / UNS N12160. We are an independent manufacturer and are not affiliated with or endorsed by Haynes International, Inc. All data in this guide is cross-referenced with ASTM, ASME, and published corrosion science literature.
Chemical Composition of HAYNES HR-160 (UNS N12160)
UNS N12160 contains (wt%): Ni ~37% (balance) · Co 27–33% · Cr 26–30% · Si 2.4–3.0% · Fe max 3.5% · Mn max 1.5% · Mo max 1.0% · W max 1.0% · Nb max 1.0% · Ti 0.2–0.8% · C max 0.15% · P max 0.030% · S max 0.015%. The simultaneous high Cr and Si is unique among wrought nickel alloys.
Composition is governed by ASTM B572 / ASME SB-572 (bar/rod), ASTM B435 / ASME SB-435 (plate/sheet), and ASTM B622 / ASME SB-622 (seamless tube). Forged product forms follow the same chemistry envelope.
| Element | Symbol | Min wt% | Max wt% | Typical wt% | Function in Alloy |
|---|---|---|---|---|---|
| Nickel | Ni | 25.0 | Balance | ~37 | Austenitic FCC matrix; corrosion-resistance foundation |
| Cobalt | Co | 27.0 | 33.0 | ~29 | Solid-solution strengthening; thermal stability |
| Chromium | Cr | 26.0 | 30.0 | ~28 | Cr₂O₃ primary scale; oxidation & sulfidation resistance |
| Silicon * | Si | 2.40 | 3.00 | ~2.75 | Key differentiator: SiO₂ sub-scale blocks sulfur diffusion to base metal |
| Iron | Fe | — | 3.50 | ~1.5 | Incidental; controlled to preserve Ni-Co balance |
| Manganese | Mn | — | 1.50 | ~0.5 | Deoxidizer during melting |
| Molybdenum | Mo | — | 1.00 | ~0.2 | Secondary solid-solution strengthener |
| Tungsten | W | — | 1.00 | ~0.2 | Secondary solid-solution strengthener |
| Niobium | Nb | — | 1.00 | ~0.2 | Carbide former; grain boundary stabilizer |
| Titanium | Ti | 0.20 | 0.80 | ~0.5 | Grain stabilization; secondary carbide formation |
| Carbon | C | — | 0.15 | ~0.05 | Strengthening carbides; tightly controlled |
| Phosphorus | P | — | 0.030 | — | Impurity limit |
| Sulfur | S | — | 0.015 | — | Impurity limit |
Why Silicon is the Critical Element: The simultaneous presence of ≥26% Chromium and ≥2.4% Silicon is found in no other broadly available wrought nickel alloy. Chromium forms the primary Cr₂O₃ outer scale; Silicon forms a dense SiO₂ sub-scale at the metal–oxide interface. This two-layer barrier is the mechanism responsible for HR-160’s unique ability to resist simultaneous sulfidation + chloridation + oxidation attack — the defining failure mode in waste incineration, pulp mill recovery boilers, and mixed-fuel combustion systems.
Mechanical Properties of UNS N12160
HAYNES HR-160 (UNS N12160) minimums: Tensile Strength ≥724 MPa · Yield Strength (0.2%) ≥321 MPa · Elongation ≥66%. Max continuous service: 1204 °C (2200 °F). Austenitic structure: does not form embrittling sigma or mu phase during long-term aging at 650–870 °C.
| Temperature | UTS (MPa, typical) | 0.2% YS (MPa) | Elongation (%) | Notes |
|---|---|---|---|---|
| 23 °C (Room Temp) | ≥724 | ≥321 | ≥66 | Solution-annealed; minimum specification values |
| 538 °C (1000 °F) | ~620 | ~280 | >50 | Typical forged bar data |
| 760 °C (1400 °F) | ~500 | ~240 | >40 | Good ductility retained |
| 982 °C (1800 °F) | ~310 | ~180 | >30 | ASME Code Case 2385 upper design limit |
| 1093 °C (2000 °F) | ~175 | ~130 | >25 | Near continuous service ceiling |
Microstructural stability: Long-term aging at 650–870 °C does not produce embrittling sigma (σ) or mu (μ) intermetallic phases that severely damage ductility in many competing alloys. Instead, only Cr₂₃C₆ carbides and a benign Ni₁₆Ti₆Si₇ G-phase precipitate — with far less impact on room-temperature toughness after elevated-temperature service.
Corrosion Resistance Performance
HR-160’s corrosion performance profile is its defining commercial advantage. Unlike alloys engineered for a single mechanism, HR-160 resists multiple simultaneous attack modes — precisely the condition found in waste incineration, mixed-fuel power generation, and chemical process environments.
Note: Performance index ratings below are engineering assessments based on published ASTM corrosion data and field service literature. They are not customer reviews or third-party ratings.
Why HR-160 Dominates in Sulfidizing Environments
Sulfidation is the primary failure mode in waste incinerators, Claus sulfur recovery plants, pulp and paper recovery boilers, and low-grade fuel combustion systems. Sulfur compounds penetrate the Cr₂O₃ scale on conventional alloys, forming rapidly growing internal sulfides that cause metal loss rates exceeding 1 mm/year on some alloy grades.
HR-160’s dual-layer oxide barrier dramatically reduces sulfur diffusion. Field data from waste incineration facilities shows HR-160 thermocouple tubes achieving service lives more than 10× longer than Ni-Cr alloys and stainless steels under identical operating temperatures and gas compositions.
Mixed Corrosive Atmosphere Performance
Real industrial environments combine sulfur compounds, chlorides, oxygen, nitrogen, and low-melting contaminants. HR-160 is validated for simultaneous resistance to:
- Sulfur — H₂S, SO₂, elemental sulfur vapor, and mixed sulfate deposits
- Chlorine & chloride salts — HCl gas, NaCl, KCl, and MgCl₂ deposits from fuel and feedstock
- Oxidizing atmospheres — high O₂ partial pressure and mixed O₂/SO₂
- Carburizing atmospheres — CO/CO₂-rich combustion gases and hydrocarbon pyrolysis products
- Low-melting compound deposits — V₂O₅, P₂O₅, Na₂SO₄ from residual fuel oils and chemical feedstocks
HAYNES HR-160 vs. Competing Alloys
| Property / Criterion | HR-160 (N12160) | Inconel 625 (N06625) | Hastelloy X (N06002) | 310 SS (S31000) |
|---|---|---|---|---|
| Max service temp (°C) | 1204 | 980 | 1175 | 1100 |
| Sulfidation resistance | Very High | Moderate | Moderate | Limited |
| Mixed atmosphere | Very High | Moderate | Moderate | Limited |
| Oxidation resistance | Very High | High | Very High | High |
| Aqueous corrosion | Moderate | Very High | High | Moderate |
| Weldability | Very High | High | High | Very High |
| Forgability | Very High | Very High | High | Very High |
| ASME code | Code Case 2385 | Sec VIII Div 1 | Sec VIII Div 1 | Sec VIII Div 1 |
Selection Rule: Choose HAYNES HR-160 whenever service involves simultaneous sulfidation + chloridation + oxidation. For purely aqueous corrosion or purely oxidizing service, Inconel 625 or Hastelloy X may provide equivalent protection at similar cost.
Forging and Hot-Working of HAYNES HR-160
HR-160 exhibits strong hot-working and cold-working behaviour — a direct result of its inherently ductile austenitic structure and absence of embrittling intermetallic phases. This makes it one of the more forging-friendly superalloys in its performance class.
- Preheat / soak temperature: 1121 °C (2050 °F). The entire billet cross-section must reach temperature uniformly before deformation begins — especially critical for heavy sections over 400 mm diameter.
- Minimum working temperature: ~980 °C (1800 °F). Surface cracking risk increases significantly below this threshold.
- Intermediate annealing: Permitted at a minimum of 1066 °C (1950 °F) between multi-stage forging passes. Rapid cooling required after each intermediate anneal.
- Post-forge heat treatment: Solution anneal at 1121 °C (2050 °F) + rapid cooling to restore optimum corrosion resistance and ductility for service.
- UT inspection: All forgings ultrasonically inspected per ASTM A388 after final heat treatment and before machining.
Sourcing HR-160 Forgings: Jiangsu Liangyi Co., Limited is an ISO 9001:2015 certified manufacturer with over 25 years of superalloy forging experience. For full size ranges, shape options, and technical specifications, see our HR-160 open-die forgings and rolled rings product page.
Cold working: HR-160’s high ductility (≥66% elongation) allows cold working. Cold-formed components must be solution annealed at 1121 °C (2050 °F) and rapidly cooled to eliminate work hardening before entering high-temperature corrosive service.
Heat Treatment of UNS N12160
HAYNES HR-160 (UNS N12160): solution anneal at 1121 °C (2050 °F), rapid cool (water quench for heavy sections; forced-air for light). Intermediate annealing: minimum 1066 °C (1950 °F). Standard supply condition: solution annealed unless otherwise specified on the purchase order.
Welding HAYNES HR-160
HAYNES HR-160 has been designed for reliable weldability across all major industrial welding processes — an important practical advantage given its widespread use in large fabricated assemblies such as recuperators, heat exchangers, and incinerator ducting.
| Process | Suitability | Filler Metal | Notes |
|---|---|---|---|
| GTAW / TIG | Preferred | Matching HR-160 filler wire | Best joint quality; preferred for root passes |
| GMAW / MIG | Good | Matching HR-160 composition wire | High-volume structural welds; faster deposition |
| Resistance Welding | Good | N/A (no filler) | Thin-section sheet; spot and seam welding |
| SMAW (Stick) | Moderate | HR-160 matched electrode | Field repair; lower quality vs. GTAW |
Pre-Weld Cleaning is Non-Negotiable: Thoroughly clean all joint surfaces and adjacent areas. Remove all grease, oil, marking compounds, sulfur compounds, and foreign materials before welding to prevent weld-zone contamination and porosity. Preferably weld in the solution-annealed condition for critical pressure-retaining joints.
Industrial Applications of HAYNES HR-160
HAYNES HR-160 has established itself across a wide range of demanding high-temperature corrosive service environments where conventional alloys have already reached their service limits:
Applicable Standards and Designations
| Standard / Body | Designation | Product Form | Notes |
|---|---|---|---|
| UNS (ASTM/SAE) | N12160 | All product forms | Primary industry identifier in North America |
| DIN / EN | W.Nr. 2.4886 | All product forms | European material number |
| ASTM B572 / ASME SB-572 | UNS N12160 | Rod and bar | Governing standard for forged bar product |
| ASTM B435 / ASME SB-435 | UNS N12160 | Plate, sheet, strip | Flat product forms |
| ASTM B622 / ASME SB-622 | UNS N12160 | Seamless pipe and tube | Covers seamless rolled ring profiles |
| ASTM B619 / ASME SB-619 | UNS N12160 | Welded pipe and tube | Welded product forms |
| ASTM A388 | UT inspection standard | Forgings | Ultrasonic test standard for all forged product |
| ASME Sec. VIII Div. 1 | Code Case No. 2385 | Pressure vessels | Approved to 982 °C (1800 °F) |
| EN 10204 | 3.1 / 3.2 MTC | All product forms | 3.1 = manufacturer-certified; 3.2 = third-party co-signed |
| API 6A | Compatible | Valve & wellhead forgings | Reference for oilfield valve body and stem materials |
How to Specify HR-160 Forged Parts: RFQ Checklist
When requesting a quotation for HAYNES HR-160 / UNS N12160 forged components, provide the following at the RFQ stage for accurate technical compliance and fast turnaround:
Frequently Asked Questions About HAYNES HR-160 (UNS N12160)
Is HAYNES HR-160 the same as UNS N12160?
What is the maximum service temperature of HAYNES HR-160?
Why does HR-160 outperform Inconel 625 in sulfidizing environments?
What is the difference between W.Nr. 2.4886 and W.Nr. 2.4880?
What ASME standard and code case apply to HAYNES HR-160 pressure vessels?
What sizes of HAYNES HR-160 forged parts are available from China?
Get a Quote for HAYNES HR-160 / UNS N12160 Forged Parts
Jiangsu Liangyi Co., Limited is an ISO 9001:2015 certified manufacturer with over 25 years of specialized experience in HAYNES HR-160 superalloy forging, supplying industrial customers across North America, Europe, the Middle East, Southeast Asia, and Australia — currently more than 50 countries.
Every forging is supplied with: EN 10204 3.1 MTC citing both UNS N12160 and W.Nr. 2.4886 · Full dimensional inspection report · UT test record per ASTM A388 · Heat treatment chart. Third-party EN 10204 3.2 MTC and independent witness inspection are available on request.
To discuss open-die forgings, seamless rolled rings, turbine shafts, valve bodies, or precision-machined near-net-shape components — visit our HR-160 product page or contact our engineering team for a no-obligation technical consultation.
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