1.6961 / 24NiCrMoV10-10 Forging Parts
ISO-Certified Manufacturer in China

1. Product Overview: EN 1.6961 24NiCrMoV10-10 Forged Steel

Founded in 1997, Jiangsu Liangyi Co., Limited operates an 80,000 m² integrated forging facility with an annual production capacity of 120,000 tons. Our facility covers the entire manufacturing chain for 1.6961 24NiCrMoV10-10 forging parts — from electric arc furnace melting and secondary refining through open-die forging, ring rolling, heat treatment, CNC machining, and full non-destructive testing — all under one roof in Jiangyin, Jiangsu Province, China.

The steel grade 24NiCrMoV10-10 (EN 1.6961) is specifically engineered for high-pressure and intermediate-pressure steam turbine rotors, gas turbine discs, and critical valve components. What sets it apart from simpler Cr-Mo steels is the addition of controlled Ni (2.0–2.8%) for low-temperature impact toughness and V (0.15–0.40%) for carbide precipitation strengthening — a combination that keeps the steel performing reliably from cryogenic storage to 500 °C service temperatures.

Every 1.6961 forging we produce comes with full material traceability from heat number to finished part, EN 10204 3.1 material certificate as standard, and optional EN 10204 3.2 third-party inspection. We produce to EN, ASTM, DIN, and customer-specific drawings with typical dimensional tolerances of ±1 mm on machined surfaces and ±3–5 mm on as-forged surfaces.

Core Advantages of Our 24NiCrMoV10-10 Forgings

2. Product Range: 1.6961 24NiCrMoV10-10 Forged Components

We supply a complete portfolio of EN 1.6961 forging parts to cover every application in the turbomachinery and power generation supply chain:

Forged Bars & Flat Bars

Round bars from 60–2,000 mm diameter, flat bars up to 800 × 400 mm cross section, and square bars from 50–600 mm. Maximum single piece length: 15 m. Maximum single piece weight: 30 tons. Delivered with 100% longitudinal UT per EN 10228-1, mechanical test certificate, and hardness survey. Typical application: turbine blade pre-forms, fastener stock, valve spindle blanks.

Seamless Rolled Rings

Produced on our 3.5 m and 5 m ring rolling mills, with OD range from 300 mm to 6,000 mm, wall thickness from 50 mm up to 600 mm, and height up to 1,500 mm. Compared to flame-cut plate circles, radial-axial rolling makes the grain flow better around the circle. Some uses are for labyrinth seal rings, casing flanges, and turbine disc forgings.

Hollow Forgings (Sleeves & Cylinders)

Hollow forgings with through-bore, including pressure sleeves, cylinder bodies, and thick-wall pipe forgings. Max OD 3,000 mm, max bore 1,500 mm, max length 5,000 mm. Inner bore UT inspection per EN 10228-3 is standard. Used in valve bodies, hydraulic cylinders, and turbine casing components.

Discs & Plate Forgings

Turbine discs, impeller blanks, and forged blocks with diameter up to 3,000 mm and thickness from 80 mm to 1,200 mm. Disc forgings are forged with controlled reduction ratios to ensure excellent axial and radial mechanical properties uniformity. Full face UT scanning is performed after rough machining.

Turbine Rotors & Integrated Shafts

Monolithic rotor shafts for 35 MW–70 MW steam turbines and generator sets. Diameter range 300–1,200 mm, length up to 15 m. Produced from a single heat-rolled ingot with no weld joints. Dynamic balancing available. 100% volumetric UT per EN 10228-3 Class 3/4 is standard for all rotor forgings.

Turbine Blades & High-Temperature Fasteners

Precision flat bar forgings for gas turbine blade pre-forms, and high-temperature fastener forgings including bolts, studs, and nuts for turbine casing and valve assembly. Full mechanical testing including high-temperature tensile test at 400 °C and 500 °C available upon request.

3. Smelting & Refining Process

The final quality of any 1.6961 forging begins at the liquid steel stage. We operate a three-stage primary refining route and offer an optional fourth-stage ESR process for the most demanding applications:

Primary Refining Route: EAF + AOD + VOD

Steel is first melted in our Electric Arc Furnace (EAF) from selected charge materials with verified low residual content. The liquid steel then passes to the Argon-Oxygen Decarburization (AOD) converter where C and S are reduced to specification and alloy additions are made with high recovery accuracy. Final ladle treatment in the Vacuum Oxygen Decarburization (VOD) unit removes dissolved gases (H < 1.5 ppm, N < 60 ppm, O < 20 ppm), ensuring low hydrogen content that is critical for avoiding hydrogen flaking in heavy section forgings.

Optional ESR (Electroslag Remelting)

For rotor forgings where maximum cleanliness and isotropy are specified — particularly for nuclear power and high-reliability turbine contracts — we offer ESR remelting as an upgrade route. ESR progressively remelts a primary electrode through a slag pool, removing oxide inclusions and producing a fine, directionally solidified structure with KAM (Key Alloying Magnification) rating typically < 1.0 per ASTM E45 Method D.

Ingot Casting & Forging Ratio

Ingots are bottom-poured and hot-topped to control segregation. Heavy ingots from 5–120 tons are used for large rotor and ring forgings. We maintain a minimum forging reduction ratio of 4:1 for all 24NiCrMoV10-10 products to fully break down the cast structure and ensure wrought, homogeneous grain flow aligned with the part geometry.

4. Chemical Composition (EN 1.6961 / 24NiCrMoV10-10)

The composition below conforms to EN 10083-3. Each batch is verified by OES before forging and reported on the EN 10204 3.1 material test report. Our internal acceptance limits for P and S are stricter than the standard minimum to ensure superior toughness in heavy sections.

Carbon Equivalent (CE) — Weldability Indicator

The International Institute of Welding (IIW) carbon equivalent for EN 1.6961 calculates to approximately:

CE = C + Mn/6 + (Cr+Mo+V)/5 + (Ni+Cu)/15 ≈ 0.86 – 1.02

This high CE value means 1.6961 is not considered a freely weldable steel and requires mandatory pre-heating and post-weld heat treatment — details covered in Section 9 below.

5. Mechanical Properties of 1.6961 24NiCrMoV10-10

Room Temperature Properties (Quenched + Tempered Condition)

• Tensile Strength (Rm): 900 – 1,050 MPa
• 0.2% Proof Stress (Rp0.2): ≥ 780 MPa
• Elongation at Fracture (A5): ≥ 13%
• Reduction of Area (Z): ≥ 40%
• Charpy Impact Energy (KV, +20 °C): ≥ 55 J
• Charpy Impact Energy (KV, −20 °C): ≥ 35 J (typical, customer spec dependent)
• Brinell Hardness (HBW): 240 – 280

High-Temperature Yield Strength Retention

The table below shows the minimum 0.2% proof stress at elevated temperature — the critical design input for HP/IP turbine rotor sizing. These values are measured on longitudinal specimens and reported with each heat per EN 10228-3 where specified.

* Typical values represent our actual production data from 2020–2024 QC records; they are not guaranteed and will vary by section size and exact heat chemistry.

6. Physical Properties of EN 1.6961

Thermal stress calculations, finite element analysis (FEA), and turbine rotor design all need to know about physical properties. The following data applies to 24NiCrMoV10-10 in the quenched and tempered condition:

Values above are representative data for engineering reference. Actual measured properties for a specific heat may vary by ±5%. We can provide heat-specific physical property test reports upon request for FEA modelling purposes.

7. Heat Treatment Protocol for 24NiCrMoV10-10

Heat treatment is the most influential process step in determining the final mechanical properties of 1.6961 forgings. Our protocol is built from 25 years of production experience with this specific grade and is reviewed by our in-house metallurgist for each order.

Standard Quench + Temper (Q+T) Protocol

1. Pre-heat (for sections > 400 mm): Slow heat to 300–400 °C at a rate not exceeding 60 °C/hour to equalise temperature through the heavy section and minimize thermal gradient stress before the austenitizing stage.
2. Austenitizing: Heat to 880–920 °C. Hold time: minimum 1 hour per 100 mm of maximum section thickness, with a minimum total hold of 2 hours. Temperature uniformity within the furnace: ±10 °C. Furnace atmosphere: slightly reducing or neutral to prevent surface decarburization.
3. Quenching: Transfer to quench tank within 30 seconds of furnace exit. Quench medium: oil or polymer (PAG) solution for sections above 200 mm; forced water quench acceptable for sections below 150 mm. Adequate agitation to achieve uniform cooling rate above 15 °C/s at the surface for sections up to 300 mm diameter.
4. Intermediate Temper (stress relief, optional): For very heavy sections (>600 mm), an intermediate temper at 200–250 °C for 2–4 hours before final tempering reduces quench cracking risk and hydrogen outgassing.
5. Final Tempering: Heat to 580–680 °C (exact temperature determined by target hardness and strength level). Hold: minimum 2 hours per 100 mm section, minimum 4 hours total. Slow controlled cooling in furnace to 150 °C before air cooling. This stage is critical — higher tempering temperature produces better toughness and lower hardness; lower tempering produces higher strength. Our standard target for most turbine rotor work is 620–650 °C.
6. Post-HT Hydrogen Bake (if required): For ESR-grade material or large bore hollow forgings, a post-temper hydrogen diffusion anneal at 200–300 °C for 24–48 hours is performed to ensure H < 1.5 ppm in the finished part.

8. Delivery Conditions for 1.6961 Forgings

Customers can specify the delivery condition for their 24NiCrMoV10-10 forgings based on whether they intend to perform their own final heat treatment or require the steel in a ready-to-use state:

Default delivery condition for all turbine forging orders is +QT unless otherwise specified. Please state your required delivery condition on the RFQ or purchase order.

9. Weldability & Machinability

Weldability of 24NiCrMoV10-10

With a carbon equivalent of approximately 0.86–1.02 (IIW formula), EN 1.6961 is classified as a restricted weldability steel. This does not mean it cannot be welded — it means that welding requires controlled procedures to avoid hydrogen-induced cracking and post-weld temper embrittlement.

Pre-Weld Requirements

• Pre-heat temperature: 200–250 °C minimum, maintained throughout welding
• Interpass temperature: 200–300 °C (do not allow to cool between passes)
• Filler metal: Low-hydrogen classified electrode (e.g., AWS E9018-B3, E10018-D2 or matching NiCrMoV type); hydrogen ≤ 4 ml/100g deposited metal
• Joint preparation: Full penetration joints preferred; remove all moisture and contaminants from joint faces

Post-Weld Heat Treatment (PWHT)

• PWHT temperature: 620–660 °C
• Hold time: Minimum 1 hour per 25 mm of maximum weld throat thickness, minimum 2 hours total
• Heating rate: ≤ 100 °C/hour above 300 °C
• Cooling rate: ≤ 100 °C/hour to 300 °C, then air cool
• Purpose: PWHT restores heat-affected zone toughness, relieves residual welding stress, and prevents delayed hydrogen cracking

Machinability of 1.6961

In the quenched and tempered condition at 240–280 HB, 24NiCrMoV10-10 machines comparably to other low-alloy steels of similar hardness. The machinability rating relative to AISI 1212 (free-cutting steel = 100%) is approximately 45–55%, which is standard for turbine-grade alloy steels.

Recommended Turning Parameters (Carbide Tooling)

Flood coolant is strongly recommended for all operations except grinding. Dry cutting is not recommended as it may cause surface thermal damage detectable by Barkhausen noise or magnetic particle testing.

10. NDT Inspection & Acceptance Standards

All 1.6961 24NiCrMoV10-10 forgings from Jiangsu Liangyi are inspected using a combination of volumetric and surface non-destructive testing before dispatch. Acceptance criteria are defined per EN 10228-3 (UT) and EN 10228-1 (MT) unless customer specifications are more stringent.

Ultrasonic Testing (UT) — EN 10228-3

EN 10228-3 defines four acceptance classes for ultrasonic inspection of steel forgings. Turbine-grade 1.6961 parts are typically specified at the higher classes:

Magnetic Particle Testing (MT) — EN 10228-1

All accessible surfaces of finished 1.6961 forgings are inspected by wet fluorescent magnetic particle testing (WFMT) under UV light. Acceptance per EN 10228-1 Class 2 or Class 3 as specified. Linear indications > 2 mm and any clusters of point indications in a 1 cm² area are cause for rejection.

Dimensional & Hardness Inspection

• Dimensional inspection: All finished dimensions verified with calibrated instruments; CMM inspection available for complex profiles
• Hardness survey: Brinell hardness (HBW 10/3000) measured at minimum 3 locations per piece; end-to-end hardness variation reported for rotor shafts
• Visual inspection: Full surface visual inspection for forging laps, seams, or surface cracks under adequate lighting per EN 10228-4

Documentation Package

• EN 10204 3.1 Material Test Report (standard) — includes chemistry, mechanical properties, hardness, UT/MT results
• EN 10204 3.2 Report (with SGS / BV / TÜV countersignature) — on request
• Heat treatment records (time-temperature charts from furnace data logger)
• Dimensional inspection report with as-forged or as-machined measurements
• Full heat traceability: ingot heat number → casting → forging → heat treatment → shipping

11. International Equivalent Grades for 1.6961 / 24NiCrMoV10-10

Engineers working across different specification systems frequently need to cross-reference EN 1.6961 with other national standards. The table below lists the closest equivalents — note that "equivalent" means similar chemistry and application intent, not identical composition. Always verify with the receiving standard before substituting.

12. How Does 1.6961 Compare to Similar Turbine Steel Grades?

The table below helps engineers select the right NiCrMoV or CrMoV grade for their application by comparing key characteristics of EN 1.6961 against the four most commonly evaluated alternatives:

Selection guidance: Choose 1.6961 when your application needs ≥ 780 MPa yield strength with reliable impact toughness at temperatures up to 500 °C. If your LP turbine requires maximum toughness with moderate strength, 26NiCrMoV14-6 (higher Ni) is the better fit. For steam pipe and valve work below 540 °C where cost is a consideration, 14MoV6-3 is a lighter-alloyed alternative.

13. Global Application Cases

Our 24NiCrMoV10-10 forgings are widely used  for power plants, turbine systems, and energy projects around the world. Following are some examples of cases from our supply history that are typical:

Steam Turbine Rotors | Southeast Asia

We have supplied monolithic HP/IP rotor shaft forgings for 35 MW–70 MW coal-fired and biomass thermal power plants in Southeast Asia. Each rotor was delivered in the +QT condition, with EN 10228-3 Class 3 UT, Charpy impact testing at –10 °C, and high-temperature tensile testing at 450 °C. These forgings have been in stable long-term service with no material-related quality issues reported.

Gas Turbine Compressor Discs | Europe

We have a long-term supply relationship with a European turbomachinery maker for precision disc forgings that are used in the compressor stages of industrial gas turbines.  The important bore diameter must have a Class 4 UT tolerance of ±0.5 mm and a 100% surface MT tolerance. The partnership has lasted for years because the deliveries are always on time and of good quality.

High-Pressure Valve Spindles | Middle East

We have manufactured custom valve spindle forgings for upstream oil and gas processing facilities across the Middle East. All parts meet NACE MR0175 hardness standards (≤ 248 HBW) thanks to controlled tempering at 660°C. We provided EN 10204 3.2 documentation that was approved by a third-party inspection and delivered the full certification package as requested by the customer.

Labyrinth Seal Rings | North America

Large-diameter seamless rolled rings up to 4.2 m OD for labyrinth seal assemblies in power generation equipment. An important requirement was circumferential thickness uniformity ≤ ±2 mm across the full ring circumference — achieved using our radial-axial ring rolling mill with in-process dimensional gauging. Full CMM dimensional report and ASTM A388 UT were provided.

Generator Rotor Shafts | East Asia

Integrated generator rotor shaft forgings for a heavy industrial client in East Asia, requiring EN 10204 3.2 with third-party inspection protocols. Our in-house melting and parallel heat treatment scheduling capability allowed us to meet an expedited delivery timeline that the customer's project schedule required.

14. Manufacturing & Quality Control

Production Equipment

• Forging presses: 2,000 T, 3,150 T, and 6,300 T hydraulic open-die forging presses for all section sizes
• Ring rolling: 3.5 m and 5 m radial-axial ring rolling mills for seamless rings up to 6 m OD
• Heat treatment: Computer-controlled pit furnaces (up to ⌀3m × 8m), car-bottom furnaces, and box furnaces with ±5 °C temperature uniformity; full thermocouple logging with printout for each cycle
• CNC machining: Horizontal and vertical CNC lathes (up to ⌀3m turning diameter), CNC milling centres, floor borers, and deep-hole drilling equipment
• NDT equipment: Phased array UT (PAUT), digital UT, wet fluorescent MT units, calibrated hardness testers (Brinell + Rockwell + portable Leeb)

Quality Control System

• ISO 9001:2015 certified quality management system; certificate available on request
• Raw material incoming inspection: OES chemistry analysis and mechanical test sampling on every heat
• Forging process records: press tonnage, reduction ratio, and forging temperature range logged per piece
• Heat treatment records: time-temperature graph from computer-logged thermocouples for every furnace load
• 100% UT and MT/PT after final machining; no forging dispatched without completed NDT sign-off
• Mechanical testing performed in our in-house testing laboratory or witnessed by third-party inspector
• Final dimensional inspection with calibrated equipment traceable to national measurement standards

15. How to Order 1.6961 24NiCrMoV10-10 Forgings

To get an accurate quotation within 24 hours, please provide the following information with your enquiry. The more detail you share, the more precise our pricing and lead time commitment will be:

1. Material specification: Confirm EN 1.6961 / 24NiCrMoV10-10 or equivalent (e.g. ASTM A470 Cl.8). State any additional chemistry restrictions (tighter P/S limits, CE limit, etc.).
2. Shape and dimensions: Provide a drawing (PDF, DXF, STEP) or specify the forging type (bar, ring, disc, shaft, hollow), key dimensions (OD, ID, length), and weight estimate. For bars, state whether as-forged or rough-machined dimensions are needed.
3. Delivery condition: State +F (as-forged), +NT (normalised+tempered), or +QT (quenched+tempered). For +QT, state target hardness range or target property level if different from EN 10083-3 standard values.
4. Quantity and delivery schedule: State pieces required, whether this is a one-time order or a blanket/call-off arrangement, and your required delivery date or lead time.
5. Inspection and certification requirements: State required UT class (EN 10228-3 Class 1–4), MT/PT requirements, and certification level (EN 10204 3.1 or 3.2). Name your preferred TPI if 3.2 is needed (SGS, BV, TÜV, Lloyds, RINA, etc.).
6. Special requirements (if any): NACE MR0175 hardness compliance (≤ 248 HBW, achievable via adjusted tempering), ESR material, high-temp tensile test at specific temperatures, hydrogen content limit, specific marking or packaging requirements, or country-specific import documentation.

16. Frequently Asked Questions

17. Related Alloy Steel Forging Grades

Depending on your service temperature, toughness requirements, and section size, the following related grades may also be relevant for your application. All are stocked or made-to-order at Jiangsu Liangyi:

Contact Us for Custom 1.6961 Forging Solutions