2.4851 (NiCr23Fe) Forging Parts | China's Professional Manufacturer
Premium NiCr23Fe open die forgings & seamless rolled rings — manufactured in Jiangyin, Jiangsu, China since 1997. The most technically detailed 2.4851 resource on the web, from a forging manufacturer with 25+ years of experience.
✔ ISO 9001:2015 Certified ✔ 50+ Countries Exported ✔ No MOQ — 30 kg to 30 Tons ✔ Forging Ratio ≥3:1 Guaranteed ✔ EN10204 3.1/3.2 MTC ✔ 24h Quote Response
1150°CMax Continuous Temp
30 TMax Single Piece
6 mMax Ring Diameter
≥3:1Forging Ratio
No MOQFrom 30 kg
50+Countries Served
4–8 wksTypical Lead Time
120,000 TAnnual Capacity
Jiangsu Liangyi Co., Limited is an ISO 9001:2015 certified manufacturer of 2.4851 (NiCr23Fe) open die forgings and seamless rolled rings, located at Chengchang Industry Park, Jiangyin City, Jiangsu Province, China (GPS: 31.9167°N, 120.2833°E; postal code 214400). Founded in 1997, with over 25 years of nickel alloy forging experience, supplying 50+ countries. Contact: sales@jnmtforgedparts.com | +86-13585067993.
What is 2.4851 (NiCr23Fe) Alloy?
2.4851 (also designated NiCr23Fe, or N06601) is a nickel-chromium-iron alloy engineered for outstanding resistance to high-temperature oxidation, carburization, and nitridation at temperatures up to 1150°C (2100°F). Its nominal composition — 58–63% Ni, 21–25% Cr, balance Fe — includes a defining addition of 1.0–1.7% Aluminum (Al) that separates it from standard nickel alloys.
The aluminum is the main differentiator. At temperatures above 800°C, aluminum selectively oxidizes ahead of chromium to form a dense, adherent α-Al₂O₃ (corundum) layer on the alloy surface. Unlike the Cr₂O₃ scale formed by aluminum-free alloys, this Al₂O₃ layer is virtually impermeable to oxygen ions — oxidation effectively stops once the layer is established. This is why 2.4851 parts in our customers' furnaces routinely outperform 2.4816 (Inconel 600) by 35–50% in service life above 950°C.
After producing over 3,000 tonnes of 2.4851 forgings since 1997, our Jiangyin engineering team has observed a consistent pattern: customers who switch from 2.4816 (Inconel 600) to 2.4851 for furnace fixtures operating above 900°C typically report the first maintenance-free replacement cycle extending from 8 months to 13–14 months.
The Al₂O₃ layer re-heals after thermal cycling — but only if the part is not mechanically abraded during service. For applications with sand blasting, abrasive media contact, or mechanical wear at temperature, 2.4856 (Inconel 625) may perform better despite its 2–3× higher raw material cost. We produce both alloys in-house and will recommend 625 when 601 is genuinely not the best fit for your application.
Complete Range of 2.4851 Forged Products
Our Jiangyin, China facility produces a full range of 2.4851 (NiCr23Fe) forgings from 30 kg to 30 tons per piece:
- Forged Bars & Rods — Round bars OD up to 2,000 mm; square, flat, rectangular, hollow bars
- Seamless Rolled Rings — OD 200–6,000 mm, wall ≥50 mm, height up to 800 mm; single ring up to 30 tons
- Forged Discs & Plates — OD up to 3,000 mm; blocks and plates for pressure vessels and turbine discs
- Hollow Components — Sleeves, pipes, tubes, shells, hubs, housings, bushings; OD up to 3,000 mm
- Valve Components — Valve balls, bonnets, bodies, stems, seat rings for gate, globe, ball, and check valves
- Pump & Turbine Parts — Impellers, shafts, casings, turbine discs, rings and blades
- Custom Near-Net-Shape Forgings — Complex profiles per drawings (DXF / DWG / PDF / STEP / IGES accepted)
Available Dimensions & Delivery Conditions
The size ranges below cover the standard production capability at Jiangsu Liangyi. Dimensions outside these ranges may be feasible on engineering review:
🔩 Round / Flat Bars
- OD: 50–2,000 mm
- Length: up to 6,000 mm
- Square: 50×50 to 600×600 mm
- Flat: width up to 1,500 mm
- Min weight: 30 kg
💍 Seamless Rolled Rings
- OD: 200–6,000 mm
- Wall thickness: ≥50 mm
- Height: 50–800 mm
- Max weight: 30,000 kg
- Ovality: ≤0.5% OD
🔘 Discs & Plates
- OD: 100–3,000 mm
- Thickness: 30–800 mm
- Rectangles: up to 3,000×1,500 mm
- Min weight: 30 kg
- Flatness: ≤2 mm/m
🛢 Hollow / Tube Forgings
- OD: 200–3,000 mm
- Wall: ≥40 mm
- Length: up to 3,000 mm
- Max weight: 20,000 kg
- Bore tolerance: H8–H11
Table 1 — 2.4851 Delivery Conditions Available from Jiangsu Liangyi
| Code | Description | Typical Use | Surface |
|---|
| +F (As-Forged) | Forged, no HT, descaled | Customer performs own HT; rough stock | Shot-blasted Ra 6.3–12.5 µm |
| +AT (Solution Annealed) | 1150–1200°C, rapid cool | Standard delivery — most applications | Shot-blasted Ra 3.2–6.3 µm |
| +AT +M (Rough Machined) | Annealed + turned to drawing + 3 mm stock | Reduce customer machining time | Turned Ra 1.6–3.2 µm |
| +AT +M +F (Finish Machined) | Fully machined to final dimensions | Drop-in replacement parts | Ra 0.8–1.6 µm or per drawing |
Chemical Composition of 2.4851 (NiCr23Fe)
Per DIN 2.4851, EN 10095, and ASTM B564 (N06601). Every heat is verified by in-house OES analysis before forging, documented on the EN10204 3.1 MTC:
Table 2 — Chemical Composition of 2.4851 (NiCr23Fe)
| Element | Min (%) | Max (%) | Role in Alloy |
|---|
| Nickel (Ni) | 58.0 | 63.0 | Austenitic matrix; base corrosion & oxidation resistance |
| Chromium (Cr) | 21.0 | 25.0 | Primary Cr₂O₃ scale former; nitridation resistance |
| Iron (Fe) | Balance (~14%) | Cost reduction; solid solution strengthening |
| Aluminum (Al) ★ Key differentiator | 1.0 | 1.7 | Forms α-Al₂O₃ layer above 800°C; defines superiority over 2.4816 |
| Carbon (C) | — | 0.10 | Controlled low to minimize Cr₂₃C₆ sensitization risk |
| Manganese (Mn) | — | 1.0 | Deoxidizer; minor solid solution strengthener |
| Silicon (Si) | — | 0.50 | Deoxidizer; carburization resistance aid |
| Sulfur (S) | — | 0.015 | Controlled low to prevent hot shortness during forging |
| Copper (Cu) | — | 1.0 | Minor; does not significantly affect HT properties |
Room-Temperature Mechanical Properties
The following minimum values apply to 2.4851 forgings in +AT (solution annealed) condition per ASTM B564 / EN 10095. Actual production values from Jiangsu Liangyi (2020–2024) consistently exceed specification minimums:
Table 3 — Room-Temperature Mechanical Properties, 2.4851 (+AT Condition)
| Property | Spec Minimum | Typical Achieved * | Test Standard |
|---|
| Tensile Strength (Rm) | 550 MPa | 620–680 MPa | ASTM A370 |
| 0.2% Proof Strength (Rp0.2) | 205 MPa | 240–280 MPa | ASTM A370 |
| Elongation (A) | 30% | 38–45% | ASTM A370 |
| Reduction of Area (Z) | — | 45–60% | ASTM A370 |
| Brinell Hardness (HB) | ≤220 HB | 150–185 HB | ASTM E10 |
| Charpy Impact (KV, −20°C) | — | ≥80 J | ASTM E23 |
* From Jiangsu Liangyi production records; not guaranteed minimums. Actual values on each order's MTC.
High-Temperature Mechanical Properties — The Data Engineers Actually Need
Room-temperature data cannot predict furnace or turbine performance. The table below — compiled from published alloy data and our production experience — gives the elevated-temperature tensile properties most supplier websites omit entirely:
Table 4 — 2.4851 (NiCr23Fe) Tensile Properties at Elevated Temperature (+AT Condition)
| Test Temp | Rm (MPa) | Rp0.2 (MPa) | Elongation A (%) | Engineering Notes |
|---|
| 20°C (RT) | 620–680 | 240–280 | 38–45 | Reference baseline |
| 200°C | 560–620 | 195–235 | 36–42 | Ductility well maintained |
| 400°C | 490–550 | 170–210 | 35–40 | Suitable for pressure vessels |
| 600°C | 430–490 | 155–190 | 32–38 | Common furnace fixture temp |
| 800°C | 300–380 | 120–155 | 30–40 | Al₂O₃ layer fully established |
| 1000°C | 120–175 | 75–105 | 35–55 | Creep-dominant regime starts |
| 1100°C | 60–90 | 40–60 | 45–70 | Grain boundary softening |
Why elongation increases above 1000°C: This is not a measurement error. As carbides dissolve and grain boundaries soften, single-phase nickel alloys enter a creep-dominant regime where deformation occurs by grain boundary sliding rather than dislocation movement. Short-term tensile strength falls dramatically, but the material does not fracture suddenly — it creeps slowly. This is why 2.4851 furnace muffle parts show gradual visible distortion before failure, giving operators warning before catastrophic cracking occurs.
Key implication: For parts operating continuously above 900°C, always design to creep rupture strength (Table 6 below), never to short-term Rp0.2. We have seen a number of customer failures caused by applying a room-temperature safety factor to a short-term tensile value at operating temperature — this approach is dangerously non-conservative for long-term high-temperature service.
Physical & Thermal Properties
These values are essential for thermal stress calculations, heat exchanger design, and electrical heating element specification:
Table 5 — Physical Properties of 2.4851 (NiCr23Fe)
| Property | 20°C | 500°C | 1000°C | Unit |
|---|
| Density | 8.11 | 7.98 | 7.82 | g/cm³ |
| Melting Range | 1320–1370 | °C |
| Specific Heat (Cp) | 448 | 510 | 590 | J/(kg·K) |
| Thermal Conductivity (λ) | 11.2 | 18.5 | 26.8 | W/(m·K) |
| Mean CTE (20°C to T) | — | 13.7 | 15.3 | ×10⁻⁶/K |
| Electrical Resistivity (ρ) | 119 | 128 | 132 | µΩ·cm |
| Young's Modulus (E) | 207 | 178 | 140 | GPa |
| Magnetic Permeability | Non-magnetic (µ ≈ 1.001) | — |
The CTE of 2.4851 (≈13.7–15.3 ×10⁻⁶/K) is significantly higher than ferritic carbon steel (≈11–12 ×10⁻⁶/K). In assemblies joining 2.4851 to carbon steel via bolts or welds, differential thermal expansion must be calculated to avoid joint cracking during heating cycles. Always consult a materials engineer for dissimilar metal joints operating above 500°C.
Creep Rupture Strength — The Critical Data for Applications Above 700°C
For parts under sustained load above 700°C, design must use creep rupture strength, not short-term tensile values. The data below gives the stress causing rupture after 100 h and 1,000 h continuous service:
Table 6 — Creep Rupture Strength of 2.4851 (NiCr23Fe), Solution Annealed +AT
| Temperature | Rupture Stress — 100 h (MPa) | Rupture Stress — 1,000 h (MPa) | Typical Application |
|---|
| 700°C | 230–265 | 175–210 | Steam superheater supports |
| 800°C | 130–165 | 95–125 | Gas turbine combustion liners |
| 900°C | 65–90 | 42–62 | Furnace muffles, radiant tubes |
| 1000°C | 28–42 | 17–27 | Annealing baskets (light load) |
| 1050°C | 16–24 | 9–15 | Thermocouple protection tubes |
A real failure case from our customer support files: A customer specified a 2.4851 conveyor belt support bar at 40 MPa working stress at 950°C, derived from room-temperature Rp0.2 of 250 MPa with a safety factor of 6. This looks conservative — but the 1,000-hour rupture stress at 950°C is only 30–40 MPa. The bar crept and deformed out of tolerance in 8 months. Redesigning to 20 MPa working stress (safety factor ~2.0 on creep rupture) extended service life beyond 24 months.
Rule of thumb from our engineering team: For furnace parts above 850°C, design working stress ≤ 50% of the 1,000-hour rupture stress at operating temperature. Apply 2.0 safety factor minimum on creep data, not 6.0 on room-temperature yield.
Alloy Decision Guide: 2.4851 vs Competing Alloys — A Manufacturer's Honest Assessment
This comparison is written from 25 years of production and customer feedback data — not from alloy marketing materials. Jiangsu Liangyi produces all four alloys listed and recommends competitors' alloys when they genuinely suit the application better:
Table 7 — 2.4851 (NiCr23Fe) vs Competing Alloys: Head-to-Head Comparison
| Property / Factor | 2.4851 NiCr23Fe | 2.4816 NiCr15Fe (Inconel 600) | 2.4856 NiCr22Mo9Nb (Inconel 625) | 1.4841 (310S Stainless) |
|---|
| DIN / UNS | 2.4851 / N06601 | 2.4816 / N06600 | 2.4856 / N06625 | 1.4841 / S31008 |
| Ni Content | 58–63% | 72% min | 58% min | 19–22% |
| Al Content (oxidation key) | 1.0–1.7% ★ | None | 0.4% max | None |
| Max Continuous Service Temp | 1150°C ★ | 1000°C | 980°C | 1050°C (lower load) |
| Oxidation Resistance (air, 1000°C) | Excellent ★ | Good | Good | Moderate |
| Carburization Resistance | Very Good ★ | Good | Very Good | Moderate |
| Aqueous Corrosion Resistance | Good | Excellent ★ | Excellent ★ | Moderate |
| Chloride Pitting Resistance | Moderate | Moderate | Excellent ★ (PREN ~51) | Low (PREN ~24) |
| Weldability | Good — ERNiCrFe-13 | Good — ERNiCrFe-7 | Excellent — ERNiCrMo-3 | Good — ER310 |
| Forging Difficulty | Moderate (well-proven) | Easy | Harder (Nb segregation) | Moderate |
| Relative Raw Material Cost | $ (Base reference) | $ (Similar) | $$$ (2–3× higher) | $$ (30–40% lower) |
| Best For | Furnace fixtures, gas turbines, radiant tubes, nuclear, chemical processing above 900°C | Aqueous corrosion, alkaline solutions, food processing, low-temperature furnace use | Offshore oil & gas, seawater, severely corrosive environments, fatigue-important parts | Lower-cost furnace parts, heat exchanger baffles, non-critical HT fixtures |
When NOT to choose 2.4851 — our engineers' honest advice:
1. Strongly reducing atmospheres with very low O₂ partial pressure (H₂/CH₄ mixtures <10⁻²⁰ atm O₂): The Al₂O₃ layer cannot form; internal oxidation and nitridation occur. Consider 2.4360 (Alloy 400) or higher-Ni superalloys.
2. Seawater or chloride-rich aqueous environments: 2.4851 is not optimized for chloride pitting. Use 2.4856 (Inconel 625) or 1.4547 (254 SMO) instead. We have seen 2.4851 flanges in offshore seawater applications fail from pitting within 6 months — an application where 2.4816 would actually perform better.
3. Applications requiring PWHT at 650–750°C: Carbide sensitization can occur in this range. For welded pressure vessels needing stress relief in this temperature window, specify low-carbon variants or consider 2.4856 (no sensitization risk due to niobium stabilization).
2.4851 International Standard Cross-Reference
All the following designations refer to the same alloy. Procurement teams searching under any of these names are looking for 2.4851 (NiCr23Fe):
Table 8 — 2.4851 (NiCr23Fe) Equivalent Designations by Standard
| Standard Body | Designation | Country/Region | Full Reference |
|---|
| DIN / EN | 2.4851 / NiCr23Fe | Germany / Europe | DIN 2.4851; EN 10095 |
| ASTM / UNS | N06601 | USA | ASTM B564 (forgings), B167 (tube) |
| ASME | SB564 / SB167 | USA | ASME Boiler & Pressure Vessel Code |
| ISO | NiCr23Fe (ISO 9722) | International | ISO 6208, ISO 9722 |
| JIS | NCF 601 | Japan | JIS G4902 |
| BS | NA 49 | United Kingdom | BS 3075, BS 3076 |
| GOST | ХН60ВТ | Russia / CIS | GOST 5632 |
| Trade Names | Inconel 601 (Special Metals); Nicrofer 6023 H (VDM); Pyromet 601 (Carpenter) | Global | Manufacturer proprietary |
Our 2.4851 Forging Manufacturing Process — Jiangyin, China
At our Jiangyin, Jiangsu plant, Jiangsu Liangyi controls the entire production chain from alloy melting to final inspection. This vertical integration eliminates quality gaps that occur when brokers source forgings from third-party foundries:
Alloy Melting
EAF → LF → VOD
30-ton capacity
OES verified
Ingot / Billet
Cast & homogenized
Soaking 1180–1220°C
UT pre-check
Open Die Forging
2,000–6,300 T press
Ratio ≥3:1 guaranteed
Temp monitored
Ring Rolling
1 m / 5 m machines
OD up to 6,000 mm
Laser geometry check
Heat Treatment
10 computer furnaces
+AT: 1150–1200°C
Data-logged records
CNC Machining
Per customer drawing
ISO 2768 tolerances
CMM verified
Final Inspection
100% UT + FPI
OES + mech. test
EN10204 3.1/3.2 MTC
Export Packing
ISPM 15 crate
VCI film + desiccant
Photo documentation
Why Forging Ratio ≥3:1 Matters — The Insider Explanation
Forging ratio (reduction ratio) = starting billet cross-section ÷ finished forging cross-section. Jiangsu Liangyi guarantees minimum 3:1 for all 2.4851 forgings — a specification many competitors omit. Here is why it matters:
As-cast nickel alloy ingots contain dendritic segregation (core richer in Ni, interdendritic zones richer in Cr/Fe) and shrinkage porosity (micro-voids from solidification). At forging ratio below 2.5:1, these defects may survive into the finished forging — invisible on dimensional inspection but detected by UT or causing in-service failure. At 3:1 reduction:
- Dendritic segregation is mechanically broken up and diffused by subsequent heat treatment
- Micro-porosity is welded shut under compressive forging stress (compressive closure requires 3:1+ reduction for nickel alloys)
- Grain matrix refines from as-cast ASTM 1–3 to forged ASTM 4–7
- Impact toughness and fatigue life improve 30–60% versus as-cast or low-reduction forgings
How to verify your supplier's forging ratio: Request the starting billet dimensions (diameter and length) on the material test report alongside finished forging dimensions. Calculate: FR = (D_billet)² ÷ (D_forging)² for round sections. If a supplier cannot provide billet traceability, they cannot prove their forging ratio. At Jiangsu Liangyi, billet dimensions and heat number are reported on every MTC — you can verify our forging ratio independently.
Heat Treatment Procedures for 2.4851 Forgings
Table 9 — Heat Treatment Procedures for 2.4851 (NiCr23Fe), Jiangsu Liangyi Standard
| Treatment | Temperature | Hold Time | Cooling | Purpose |
|---|
| Solution Annealing (+AT) — Standard | 1150–1200°C | Min 1 h per 25 mm thickness | Rapid air or water quench below 400°C within 3 min | Dissolve carbides; maximize corrosion resistance & ductility |
| Stress Relief | 870–980°C | 2–4 hours | Air cool | Relieve forging residual stress without full recrystallization |
| Sensitization Zone (AVOID) | 650–750°C | Any duration | — | Cr₂₃C₆ precipitation at grain boundaries — reduces corrosion resistance. Never hold at these temperatures. |
| Pre-heat for Welding | No preheat required (<50 mm) | — | — | For >50 mm, warm to 100–150°C |
| Post-Weld HT (PWHT) | 900–950°C | 2 hours | Air cool rapidly through 650°C | Improve HAZ ductility; not mandatory but recommended for pressure vessels |
2.4851 (NiCr23Fe) Weldability & Fabrication Guide
2.4851 has good weldability by all standard arc processes. However, the aluminum content that gives it superior oxidation resistance also creates specific challenges absent in lower-aluminum nickel alloys. This section is based on our engineering team's direct experience preparing weld qualification coupons and reviewing customer welding procedure specifications (WPS).
Table 10 — Filler Metal Recommendations for Welding 2.4851 (NiCr23Fe)
| Process | Recommended Filler | AWS Classification | Notes |
|---|
| GTAW (TIG) — Preferred | ERNiCrFe-13 (matching filler) | AWS A5.14 | Best oxidation resistance match; use for all HT service above 700°C |
| GTAW / GMAW (alternative) | ERNiCrFe-7 (Inconel 82) | AWS A5.14 | Lower Al; acceptable below 800°C; better hot crack resistance |
| SMAW (Stick) | ENiCrFe-12 | AWS A5.11 | Field repairs; control heat input carefully |
| SAW (Submerged Arc) | ERNiCrFe-13 + basic flux | AWS A5.14 | Not preferred — Al burn-off and porosity risk; avoid for HT service |
| Dissimilar — to carbon steel | ERNiCr-3 (Inconel 82) | AWS A5.14 | Buffer layer; limit dissimilar joint to service below 500°C due to CTE mismatch |
Key Welding Precautions for 2.4851
- Cleanliness is critical: Nickel alloys are extremely sensitive to sulfur and phosphorus. Degrease all surfaces within 50 mm of the weld joint with acetone before welding. Fingerprints (sulfur from sweat), cutting oil, paint, and marking ink all cause weld cracking.
- Low heat input: Target below 1.5 kJ/mm. High heat input causes grain coarsening in the HAZ, reducing toughness. Multiple thin passes are better than fewer thick passes.
- Back-purge with argon: For tube and pipe welds, back-purge with argon (dew point ≤−40°C) to prevent Al₂O₃ inclusions in the root pass. Failure to back-purge creates brittle oxide inclusions detectable on radiographic testing (RT) or causing root pass cracking.
- Interpass temperature: Maximum 150°C. Allow each pass to cool. Do not peen — nickel alloys are susceptible to strain-age cracking.
- Avoid sensitization range: Never allow slow cooling through 650–750°C during any stage of fabrication or PWHT. Use a water-cooled quench fixture if needed for heavy sections.
Common Failure Modes in 2.4851 Forgings — And How to Prevent Them
Based on 25 years of post-failure analysis from our global customer base, these are the most common root causes of 2.4851 part failure in service:
❌ Failure Mode 1: Thermal Fatigue Cracking
Repeated rapid thermal cycling (furnace doors opened frequently, quench-and-reheat operations) causes surface tensile stresses on cooling that initiate cracks after hundreds to thousands of cycles. Presents as a surface crazing network after 6–18 months.
Specify +AT condition for maximum ductility. Reduce thermal shock rate. Use thinner cross-sections to equalize temperature gradient. For severe cycling (>500 cycles/year with ΔT >600°C), consider 2.4856 (Inconel 625) for better fatigue resistance.
❌ Failure Mode 2: Creep Deformation at Operating Temp
Part slowly deforms out of tolerance over months/years above 900°C under sustained load, even at stresses well below room-temperature yield strength. Common in furnace basket supports and conveyor parts.
Design to 1,000-hour creep rupture strength (Table 6 above). Apply safety factor of 2.0–2.5 on rupture stress. Never apply a room-temperature-derived safety factor to short-term Rm at operating temperature.
❌ Failure Mode 3: Intergranular Oxidation (IGA)
Oxygen penetrates grain boundaries faster than the Al₂O₃ layer forms, causing grain boundary attack. Seen when parts heat up slowly through 500–800°C in air, or after contamination with sulfur compounds (SO₂, H₂S, organic residues).
Ensure rapid heat-up through 500–800°C range. Keep operating atmosphere free of sulfur. Inspect incoming feedstock for pre-existing sensitization using ASTM A262 Practice E. Clean machined surfaces before installation.
❌ Failure Mode 4: Aqueous SCC in Preheaters
Stress corrosion cracking in aqueous environments (steam preheaters, heat exchangers) exposed to chloride-bearing fluids above 80°C. Not a risk in dry gas service, but seen in mixed-phase applications.
For aqueous service above 80°C with chlorides, upgrade to 2.4856 (Inconel 625) or 2.4858 (Alloy 825). Remove residual forming stress via full solution anneal. Avoid crevice geometries in the joint design.
❌ Failure Mode 5: Residual Porosity from Low Forging Ratio
Residual casting porosity from an ingot worked at forging ratio <2.5:1 appears as linear UT indications. Parts may pass dimension test and visual check, but fail UT acceptance or crack in pressure test.
Specify minimum forging ratio 3:1 in the purchase order. Request billet traceability documentation. Require 100% UT per ASTM A388. Jiangsu Liangyi guarantees ≥3:1 and documents billet dimensions on every MTC.
❌ Failure Mode 6: HAZ Cracking After Welding
Heat-affected zone cracking ("liquation cracking" or "ductility dip cracking") in 2.4851 welds caused by S/P impurities at grain boundaries combined with weld residual tension stress. Often seen in first repair welds on in-service parts.
Follow all welding precautions in Section 10. Clean with acetone. Low heat input (<1.5 kJ/mm). For weld-important applications, specify forging chemistry with S <0.010% and P <0.015% — we routinely get S <0.008% at our Jiangyin melt shop.
Industrial Applications & Global Case Studies
2.4851 (NiCr23Fe) forgings are specified across six major industries where temperatures exceed 700°C or where combined high-temperature and corrosive conditions exist:
Heat Treatment Industry
Annealing baskets, carburizing fixtures, nitriding trays, radiant tubes, muffles, retorts, flame shields, conveyor belts and burner nozzles. The dominant global application — 2.4851 is the standard alloy for furnace internals above 900°C.
Typical Application: 2.4851 radiant tubes operating at 970–990°C in controlled endothermic atmospheres. Customers switching from 2.4816 to 2.4851 in this temperature range consistently report longer service intervals due to the superior Al₂O₃ oxidation layer. We supply radiant tubes in custom diameters and lengths with +AT condition as standard.
Power Generation
Gas turbine combustion liners, transition ducts, diffuser assemblies, containment rings; steam turbine parts; superheater supports; thermocouple sheaths and grid spacers in nuclear reactors.
Typical Application: 2.4851 seamless rolled rings for gas turbine hot section parts operating above 1000°C. We produce rings in OD 500–3,000 mm for combustion liners, transition ducts, and containment rings. EN10204 3.1 or 3.2 MTC available; third-party inspection arranged upon customer request.
Nuclear Power
Reactor coolant pump casings, impellers, containment seal chambers; thermocouple protection tubes; atmosphere generators for fuel rod processing. ASME Section III compliance needed.
Typical Application: 2.4851 large-diameter forgings for nuclear power plant auxiliary parts needing ASME material documentation. We produce discs and rings up to OD 3,000 mm with 100% UT per ASTM A388 and full material traceability. Customers' authorized inspection agencies review and co-sign documentation as required.
Oil & Gas
Wellhead Christmas trees, casing heads, tubing hangers; valve bodies, stems and seat rings for sour service (H₂S); sour water stripper condenser parts. API 6A material requirements.
Typical Application: 2.4851 valve body forgings for sour service (H₂S) environments. We produce valve blanks meeting NACE MR0175 / ISO 15156 chemistry and hardness requirements, with full MTC documentation. Hydrostatic testing per customer specification available on-site. Typical lead time 6–8 weeks from order confirmation.
Chemical Processing
Nitric acid (HNO₃) production catalyst grids; ammonia reformer furnace internals; catalyst regenerator components; ethylene cracking furnace elements; sulfuric acid air preheaters.
Typical Application: 2.4851 large rings and discs for chemical plant reactors and catalyst supports at 600–700°C in corrosive gas atmospheres. We produce rings up to OD 6,000 mm, wall from 50 mm. High Cr + Al content provides excellent resistance to nitric acid vapors at elevated temperatures.
Aerospace & Defense
Jet engine igniter brackets, combustion chamber liners; afterburner components; industrial gas turbine combustion baskets; high-temperature test rig fixtures.
Typical Application: 2.4851 precision-machined rings for high-temperature combustion and turbine parts. We machine rings to dimensional tolerances of ±0.1–0.2 mm with 100% FPI on all finished surfaces. First-article inspection (FAI) documentation available. All machining performed under ISO 9001:2015 quality system at our Jiangyin facility.
Standards, Certifications & Quality Assurance
Our 2.4851 (NiCr23Fe) forgings are produced to the following international material standards and can be supplied with documentation meeting:
- ASTM B564 / ASME SB564 — Material standard for Nickel Alloy Forgings (N06601)
- DIN 2.4851 / EN 10095 — Heat-resistant steels and nickel alloys
- API 6A (PSL1–PSL4) — Material requirements for wellhead and Christmas tree equipment
- ASME Section VIII Div.1 / Div.2 — Material & dimensional requirements for pressure vessel parts
- ASME Section III — Material requirements for nuclear power plant components (customer's N-Stamp contractor responsible for final certification)
- NACE MR0175 / ISO 15156 — Sour service (H₂S)
- ISO 9001:2015 — Full facility Quality Management System (certificate available upon request)
Quality control is 100% — not sampling:
- 100% Ultrasonic Testing (UT) per ASTM A388, acceptance Level B or C per customer spec
- 100% Fluorescent Penetrant Inspection (FPI) per ASTM E165 on all machined surfaces
- OES chemical analysis (ASTM E1086) — every heat, before forging begins
- Mechanical testing (tensile, hardness, Charpy impact) per ASTM A370 — every heat/lot
- EN10204 3.1 standard; 3.2 (co-signed by independent inspector) on request
- Full traceability: heat number → cast number → forging number → test certificate number
- Third-party inspection: SGS, Bureau Veritas (BV), TÜV SÜD, Lloyd's Register (LR) upon request
- Customer source inspection at our Jiangyin, China facility is welcome at any stage
Why Choose Jiangsu Liangyi as Your 2.4851 Forging Partner?
- 25+ Years Specialized in Ni-Alloy Forging: Founded 1997; sole focus on high-temperature and corrosion-resistant alloy forgings
- Fully Integrated Production: 30-ton EAF+LF+VOD → 6,300-ton press → 5-meter ring roller → 10 HT furnaces → CNC machining → full inspection lab — all in Jiangyin
- Guaranteed Forging Ratio ≥3:1: Documented on every MTC with billet traceability
- No MOQ: 30 kg prototypes to 30-ton production pieces — identical quality standards
- Full Dimension Range: Rings OD 200–6,000 mm; bars up to 2,000 mm OD; single pieces up to 30 tons
- 50+ Countries Exported: USA, Germany, UK, Netherlands, Japan, South Korea, Australia, Saudi Arabia, UAE, India, Brazil, and more
- 120 km from Shanghai Port: Fast, cost-effective worldwide shipping via FOB / CIF / DDP
- T/T and L/C Payment: T/T (30% + 70%) or L/C at sight for orders >USD 50,000
- 24-Hour Quote Response: Send drawings to sales@jnmtforgedparts.com
How to Order — 5-Step Process
1
Send Inquiry
Email drawings (DXF / DWG / PDF / STEP / IGES), quantity, material grade (2.4851), delivery condition (+AT or machined), required standard.
⏱ Your action: ~5 min 2
Technical Review & Quote
Engineers review drawings, confirm DFM feasibility, return quotation with weight, unit price, lead time, and engineering notes.
⏱ Our response: within 24 h 3
Order Confirmation
Confirm PO. We issue Manufacturing & Quality Control Plan (MQCP) for your review. 30% T/T deposit typically required.
⏱ 1–3 business days 4
Production & Inspection
Full production per MQCP. Progress photos on request. Third-party inspection arranged. EN10204 3.1/3.2 MTC prepared.
⏱ 4–12 weeks (by product) 5
Packing & Shipment
ISPM 15 crates + VCI film + desiccant. Balance T/T or L/C payment. Full export documentation provided.
⏱ 3–5 days packing Packaging, Trade Terms & Payment
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Wooden Crates
ISPM 15 certified fumigated wood. Custom sizes per forging dimensions.
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Anti-Corrosion
VCI (Vapor Corrosion Inhibitor) film wrapping + silica gel desiccant. 2-year protection guarantee.
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Incoterms
FOB Shanghai / Ningbo; CIF worldwide; DDP to your door. EXW Jiangyin for customer forwarder.
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Payment Terms
T/T: 30% deposit + 70% before shipment. L/C at sight for orders >USD 50,000.
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Documents
Commercial Invoice, Packing List, B/L, CO (Form A/E), EN10204 3.1 or 3.2 MTC, UT/FPI reports.
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Lead Times
Raw +AT: 4–6 wk. Rough machined: 6–8 wk. Finish machined: 8–12 wk. Rush negotiable.
Frequently Asked Questions — Answered by Our Engineers
What is the maximum temperature 2.4851 (NiCr23Fe) can withstand?
1150°C (2100°F) continuous in oxidizing air atmospheres. For intermittent service, peak excursions to 1200°C are tolerable with reduced lifetime. The aluminum content (1.0–1.7%) forms an α-Al₂O₃ protective layer above ~800°C that effectively halts further oxidation. In reducing atmospheres with very low oxygen partial pressure, the Al₂O₃ layer cannot form — consult our engineers for atmosphere-specific guidance.
What is the difference between 2.4851 and Inconel 600 (2.4816)?
The important difference is aluminum content: 2.4851 contains 1.0–1.7% Al; Inconel 600 (2.4816) contains none. Above 900°C, 2.4851's Al₂O₃ layer provides 3–5× better oxidation resistance than the Cr₂O₃ layer alone. In our 25+ years of production, customers switching from 2.4816 to 2.4851 for furnace fixtures above 950°C report 35–50% longer service life. Inconel 600 is preferred for aqueous corrosion applications (higher Ni ~72%, better in alkaline solutions) or where temperature stays below 850°C. For dry high-temperature oxidizing/carburizing service above 900°C, 2.4851 is the clear technical choice.
Is 2.4851 (NiCr23Fe) weldable? What filler metal should I use?
Yes, 2.4851 has good weldability. For service above 700°C, use ERNiCrFe-13 (AWS A5.14) for best oxidation resistance matching. For service below 800°C or where crack resistance is critical, ERNiCrFe-7 (Inconel 82) is acceptable. Key precautions: degrease all surfaces with acetone (nickel is sulfur-sensitive), heat input <1.5 kJ/mm, back-purge tube welds with argon, interpass temperature ≤150°C, and avoid slow cooling through 650–750°C sensitization range. See Section 10 for full welding guide.
What is the minimum order quantity (MOQ)?
Jiangsu Liangyi has no minimum order quantity. We accept single-piece prototype orders from 30 kg upward — possible because we melt and forge in-house and are not dependent on third-party foundry minimums. Contact sales@jnmtforgedparts.com with your specific requirements for a free quotation. What heat treatment is standard for your 2.4851 forgings?
Standard delivery is solution annealed (+AT): 1150–1200°C, minimum 1 hour per 25 mm thickness, then rapidly cooled to below 400°C within 3 minutes (air or water quench). This dissolves Cr₂₃C₆ carbides (preventing sensitization) and recrystallizes grain matrix for maximum ductility and corrosion resistance. We operate 10 computer-controlled furnaces with data-logged temperature records included in the quality dossier. Alternative conditions (+F, stress relief, custom HT cycles) available on request.
What is the typical lead time?
From our Jiangyin, China facility: 4–6 weeks raw (+AT) forgings; 6–8 weeks rough machined; 8–12 weeks finish machined with full inspection documentation. For simple shapes, 4-week delivery is achievable. For intricate geometries needing first-article inspection (FAI), add 1–2 weeks. Expedited production is negotiable — contact us with your deadline.
What international standards do your 2.4851 forgings comply with?
ASTM B564 / ASME SB564, DIN 2.4851 / EN 10095, API 6A (PSL1–PSL4), ASME Section VIII Div.1/Div.2, ASME Section III (nuclear), NACE MR0175 / ISO 15156 (sour service). ISO 9001:2015 certified. EN10204 3.1 MTC standard; 3.2 available. Third-party inspection: SGS, BV, TÜV SÜD, Lloyd's Register.
Do you ship internationally? What are your trade terms?
Yes. We ship from Shanghai Port (120 km from our Jiangyin factory) worldwide. Incoterms: FOB, CIF, DDP, and EXW. Payment: T/T (30% deposit + 70% before shipment) or L/C at sight for orders >USD 50,000. We currently export to more than 50 countries including USA, Germany, UK, Netherlands, France, Japan, South Korea, Australia, UAE, Saudi Arabia, India, and Brazil. Full export documentation is provided with every shipment.