2.4654 (NC20K14, NiCr20Co13Mo4Ti3Al) Forged Parts — China Manufacturer, Global Delivery

What Makes 2.4654 (NC20K14, NiCr20Co13Mo4Ti3Al) a Premier Forging Material?

At Jiangsu Liangyi, we have spent more than 25 years working exclusively with difficult-to-forge nickel-based superalloys — and among them, 2.4654 stands apart. Registered under EN 10302 as material number 2.4654, known as NC20K14 in the French standard, and fully described by its compositional name NiCr20Co13Mo4Ti3Al, this alloy was engineered specifically for one purpose: to keep rotating and static machinery running reliably at temperatures where almost every other structural metal begins to fail. What drives that capability is a dual-mechanism strengthening system that few superalloys replicate as effectively. The nickel-chromium-cobalt solid-solution matrix supplies a tough, stable backbone resistant to oxidation and hot corrosion. Simultaneously, a controlled precipitation of γ' (gamma prime) intermetallic phase — triggered by aluminium and titanium additions during age-hardening heat treatment — anchors dislocation movement at elevated temperatures, delivering the creep rupture strength that turbine and valve designers depend on. Molybdenum reinforces both mechanisms simultaneously: it broadens the solid solution and retards grain-boundary diffusion, extending the alloy's long-term dimensional stability under cyclic thermal loading.

2.4654 vs. Alloy 718 vs. Alloy 625 — Why Engineers Upgrade to 2.4654

Procurement engineers frequently ask us when the step up from Alloy 718 or Alloy 625 becomes justified. The short answer is: when continuous operating temperatures climb above 650 °C, or when creep life and fatigue cycles are contractually guaranteed over multiple decades. The table below captures the key differentiators that drive that decision at the metallurgical level:

The important insight in that table is the γ'' overaging threshold for Alloy 718. Above approximately 650 °C, the metastable γ'' precipitate transforms to the stable δ phase, causing the alloy to lose the very strengthening mechanism that makes it useful. 2.4654's γ' phase has no equivalent thermal instability — it remains coherent with the matrix up to its design temperature limit, which is why turbine OEMs in Europe and Asia specify it by name for parts that must outlast a 25-year power station overhaul cycle.

Complete 2.4654 / NC20K14 Forged Product Portfolio

Our forging product range for 2.4654 covers single-piece weights from 30 kg up to 30 metric tons. Every geometry listed below is produced in-house under a single roof at our Jiangyin facility — from ingot to finished forging — giving customers one accountable source and a single unbroken material traceability chain.

Open Die Forged Bars, Rods and Billets

Round bars, square bars, flat bars, step bars and precision-tolerance billets in 2.4654 alloy, with maximum diameter reaching 2,000 mm. The open-die process produces a refined, directional grain matrix that resists stress-rupture crack propagation — a property particularly valued in turbine blade root blanks, high-temperature fastener bar stock and valve spindle forgings where fatigue loading is cyclic rather than purely static.

Seamless Rolled Forged Rings

NC20K14 seamless rings, contoured profile rings, flanged rings, labyrinth seal rings and guide rings rolled to maximum outer diameters of 6,000 mm. The ring rolling process closes porosity and aligns the grain flow circumferentially — the orientation that resists the hoop stresses acting on turbine casings, bearing housings and pressure-retaining flanges during thermal cycling. Tolerances are held to DIN 7527 or tighter on request.

Hollow Forgings and Heavy-Wall Cylinders

NiCr20Co13Mo4Ti3Al forged sleeves, cylinders, heavy-wall tube blanks and housing shells with outside diameters up to 3,000 mm. Hollow forgings produced by our hydraulic press and ring-rolling combination preserves the mechanical integrity that machining from solid bar cannot replicate — they eliminate the central low-deformation zone and deliver consistent properties wall-to-wall, which matters critically in nuclear primary-circuit housings and high-pressure valve bodies subject to pressure-cycling fatigue.

Custom Profile and Near-Net-Shape Forgings

2.4654 forged discs, impellers, blisks, hubs, turbine wheels and bespoke near-net-shape forgings with maximum diameter up to 3,000 mm. Near-net-shape tooling minimises the material removed during finish machining — an important cost factor given that 2.4654 raw material prices are substantially higher than carbon or stainless steel. We design tooling in-house using 3D solid modelling and forge-simulation software to validate metal-flow before the first heat is struck.

Our End-to-End Manufacturing Process for 2.4654 Forgings

Producing forgings to EN 10302 property guarantees in a material as compositionally sensitive as 2.4654 needs control at every stage, not just at the forging press. Our integrated facility handles the complete manufacturing sequence internally:

• Melting and Refining — Triple-Process Chemistry Control: We produce 2.4654 ingots using a sequential 30-tonne Electric Arc Furnace (EAF) → Ladle Refining Furnace (LF) → Vacuum Oxygen Decarburisation (VOD) route, with critical heats further processed through Vacuum Induction Melting (VIM). This combination gets the sub-ppm sulfur and oxygen levels that prevent low-melting-point grain-boundary films — the root cause of hot-tearing during forging of high-gamma-prime alloys.
• Forging — Controlled Deformation Ratio at Every Pass: Our press fleet — 6,300 T, 4,000 T and 2,000 T hydraulic presses alongside 5 T and 3 T electrohydraulic hammers — gives us the tonnage to forge thick cross-sections without resorting to high strain rates that cause adiabatic shear bands. For ring geometries, five radial-axial ring rolling mills spanning 1 m to 5 m diameter let us choose the machine matched to piece size, keeping the circumferential-to-radial deformation ratio within the window that produces optimal γ' distribution after heat treatment.
• Heat Treatment — Verified γ' Solvus Control: Ten computer-controlled furnaces carry out solution treatment, primary aging and secondary aging sequences tailored to the incoming forging section thickness. We monitor and record time-at-temperature curves against the metallurgical model for each production lot. Deviations outside the process window require mandatory re-evaluation before the batch advances — a protocol that deletes the variability that produces scatter in creep test results.
• Machining — Tight Tolerance, Work-Hardening Aware: CNC turning centres, milling machines, grinding machines and honing equipment finish 2.4654 forgings to drawing tolerances. Our machinists are trained specifically on nickel superalloys: cutting parameters, tooling geometry and coolant strategy are all adjusted to prevent work hardening and surface residual stress patterns that would compromise fatigue performance.
• Inspection — Full-Coverage NDT and Mechanical Verification: Ultrasonic testing (UT), magnetic particle testing (MT), liquid penetrant testing (PT) and radiographic testing (RT) are performed in-house to EN 10228 or customer-specified acceptance criteria. Mechanical property coupons are cut from each qualification test piece and tested to EN ISO 6892-1 (tensile), EN ISO 204 (creep) and EN ISO 12135 (fracture toughness) as required. Every data record is traceable to the original heat number and stored for the life of the part.

Industry Applications and Project Reference Cases

2.4654 forgings from our facility are operating in power stations, nuclear plants and process facilities across more than 50 countries. The four segments below represent our deepest reference base — with representative delivery cases that demonstrate not just volume, but the specific technical demands we routinely satisfy.

Gas and Steam Turbines — Global Power Generation

Gas and steam turbine OEMs specify 2.4654 for components where the combination of high centrifugal stress and long thermal exposure rules out every cheaper alternative. The alloy's tight grain size control during forging — achievable because we manage the deformation temperature window to stay below the γ' solvus — translates directly into the low scatter in LCF (low cycle fatigue) life data that turbine design codes require. Parts we supply to this sector include:

• Turbine disc and blisk forgings for industrial gas turbines (IGT), where bore-to-rim temperature gradients impose simultaneous tensile and compressive fatigue cycles every start-stop event
• Compressor disc and impeller forgings rated for continuous duty at inlet temperatures exceeding 550 °C
• Flat rectangular bar stock for precision-machined turbine blade aerofoil blanks
• Rotor shaft and guide ring forgings needing 100% full-volume UT to SEP 1923 Grade 3 acceptance criteria
• LPT 1st and 2nd stage turbine casing ring forgings — contoured profile rolled rings delivered with machining allowance and traceability to EN 10204 3.2 certificates
• Double-ended studs, through-bolts and high-temperature flanging fasteners requiring combined proof-load and hardness verification

Power Plant Valves and High-Pressure Pipework — Middle East and Global Oil & Gas

In ultra-supercritical steam plants operating above 600 °C and 25 MPa main steam conditions, valve internals experience a particularly aggressive combination of loads: high static pressure, high-velocity steam erosion, thermal shock during trip events, and — in some geographic markets — sulphidising atmospheres from fuel impurities. NC20K14 satisfies all of these demands simultaneously because its chromium and cobalt content provides oxidation and sulphidation resistance while the γ' precipitate keeps the yield strength needed to prevent valve-seat galling and stem deflection. We regularly produce:

• Main stop valve (MSV) and governor valve (GV) spindle and stem forgings for ultra-supercritical steam cycles, machined to H7 shaft tolerance on the stem bearing diameter
• Control valve (CV) and combined reheat valve (CRV) disc and seat forgings with hardness gradient verification across the seating face
• Valve bonnet and cover forgings for high-pressure service, delivered with full traceability documentation to support customers' pressure equipment compliance requirements
• Pipeline flange and weld-end forgings produced to NACE MR0175 / ISO 15156 chemical and hardness requirements where specified by the customer's purchase order

Nuclear Power — Safety-Level Structural Components

Nuclear applications impose requirements that go beyond any commercial standard: full material genealogy from ingot chemistry to finished part dimensions, qualification of the entire manufacturing supply chain, and long-term dimensional stability over a 60-year design life exposed to both elevated temperature and radiation flux. 2.4654 satisfies the metallurgical requirements for these roles because its γ' precipitate matrix resists both thermal ageing embrittlement and radiation-induced segregation better than ferritic and austenitic stainless steels at equivalent temperatures. Nuclear-grade 2.4654 products we have supplied include:

• Flow-limiter Venturi forgings and divider plate blanks for pressurised water reactor (PWR) steam generators
• Pressuriser surge-line nozzle forgings and reactor coolant pump flywheel forgings, both classified as safety-level parts under the applicable national nuclear code
• Control rod drive mechanism (CRDM) latch housings, rod travel housings and funnel extension forgings manufactured under a nuclear quality management plan
• Stator end-cap, bearing housing and closure ring forgings for reactor coolant pump motors
• Containment penetration sleeve and closure head forgings with full Charpy sub-size impact testing at design-basis accident temperature

Aerospace Engine Components and Industrial Compressors — North America and Global

2.4654's composition overlaps significantly with the Waspaloy specification (UNS N07001) that aerospace primes have relied on for decades in turbine disc and seal applications. This means that our forge shop's process envelope — composition, forging reduction ratio, heat treatment solvus control, grain size verification — maps directly onto AMS 5704 and AMS 5706 requirements. We provide AMS-grade 2.4654 forged compressor blades, impeller blanks, disc forgings and structural fasteners to aerospace sub-tier suppliers and MRO (maintenance, repair and overhaul) organisations in North America, Europe and Asia. For industrial compressor OEMs, the same material delivers reliable performance in centrifugal stage impellers where tip speeds exceed 550 m/s and operating temperatures at the diffuser exceed 400 °C continuously. Browse our full range of superalloy materials for additional grade options.

2.4654 / NC20K14 / NiCr20Co13Mo4Ti3Al — Material Specifications and Technical Data

All forgings we supply to this specification are produced and tested in strict conformance with EN 10302: 2008. The compositional and mechanical data below are reproduced directly from that standard; we publish them here as a reference resource for engineers at the quotation and material qualification stage. Every production batch is independently re-verified — chemistry by optical emission spectrometry (OES), mechanical properties by tensile coupon test — before any EN 10204 3.1 or 3.2 certificate is issued.

Applicable Standards

Primary governing standard: EN 10302: 2008 — Creep-resisting steels, nickel and cobalt alloys. Cross-compatible with: ASTM B637 (bar and billet), AMS 5704 (sheet, strip and plate), AMS 5706 (bar, wire and rings), ISO 9712 (NDT personnel qualification). The US UNS equivalent designation is N07001 (Waspaloy).

Chemical Composition per EN 10302: 2008 (Weight %)

Minimum Mechanical Properties — Forged Round Bar, Solution Treated + Aged

Standard Heat Treatment Sequence

The certified mechanical properties above are obtained through a two-stage precipitation-hardening cycle applied after solution treatment. The standard sequence we follow, consistent with EN 10302 and AMS 5706, is:

1. Solution Treatment: 1,080 °C ± 10 °C, minimum 4 hours, rapid air cool or faster — dissolves all precipitates and homogenises the γ matrix prior to controlled re-precipitation
2. Primary Aging: 845 °C ± 10 °C, 4 hours, air cool — nucleates a fine, uniform distribution of γ' precipitate within the austenite grains
3. Secondary Aging: 760 °C ± 10 °C, 16 hours, air cool — grows and stabilises the γ' particles to the size range that maximises creep rupture strength

Waspaloy® is a registered trademark of RTX Corporation. References to Waspaloy® on this page are for technical cross-reference and grade-equivalence identification only; Jiangsu Liangyi has no commercial affiliation with RTX Corporation or Pratt & Whitney.

Quality Certification, Manufacturing Standards and Third-Party Inspection

Our production system is built around a single verified certification: ISO 9001: 2015 Quality Management System, covering the full manufacturing scope from raw material procurement through forging, heat treatment, machining and final inspection. This provides customers with the audited quality framework needed for supply-chain qualification in industrial, energy and process markets worldwide. 

In addition to our ISO 9001 certification, we manufacture 2.4654 forgings to meet the following industry standards. Note that compliance with these standards describes the technical requirements our products are manufactured to meet — it does not imply that Jiangsu Liangyi holds independent regulatory approvals issued by the bodies that administer those frameworks:

• Material and Product Standards: EN 10302: 2008 (primary governing standard for material composition and properties); ASTM B637 (bar and billet); AMS 5704 / AMS 5706 (sheet, plate, bar and rings); EN 10228 (ultrasonic testing of steel forgings)
• Customer-Specific Regional Standards: Our forgings can be produced to meet the technical requirements of AD 2000 (German pressure vessel standard), ASME BPVC Section II material requirements, NACE MR0175 / ISO 15156 (sour service), and NORSOK M-122 / M-123 (Norwegian offshore). Customers are responsible for their own regional regulatory filings, CE marking and notified body involvement as required by local law — we provide the material documentation and test results needed to support those processes.
• EU Pressure Equipment (PED 2014/68/EU): We supply the technical documentation — EN 10204 3.1/3.2 mill test certificates, material traceability records and NDT reports — that EU importers and pressure equipment manufacturers require to fulfil their own PED obligations. Responsibility for CE marking and notified body assessment rests with the EU equipment manufacturer, not the forging supplier.
• Inspection Certificates and Third-Party Witness: All 2.4654 forgings are available with EN 10204 3.1 Mill Test Certificates as standard. EN 10204 3.2 certificates (countersigned by an independent inspection authority) are available when customers arrange third-party witness inspection. We have previously supported witness inspections conducted by DNV GL, Bureau Veritas, Lloyd's Register, ABS, RINA and TÜV-accredited bodies on behalf of end customers. Customers may nominate any approved inspector; we will accommodate witness access at any production stage.

Frequently Asked Questions — 2.4654 (NC20K14) Forgings