Alloy 24 (UNS S34565) Forged Parts — Custom Open Die Forgings & Seamless Rolled Rings From China
Updated: | Published:
Alloy 24 (UNS S34565) — At a Glance
Alloy 24 (UNS S34565 / Werkstoff Nr. 1.4565) is a nitrogen-molybdenum alloyed super austenitic stainless steel.Its PREN value is above 40, which is three more times of 316L. Jiangsu Liangyi, established in , is an ISO 9001:2015 certified China manufacturer of producing custom Alloy 24 open die forgings (30KG-30 tons), seamless rolled rings (up to OD 6m), and forged shafts (up to 15m length) .These products are used for chemical, FGD, marine, nuclear, and oil and gas industries worldwide.
Jiangsu Liangyi Co., Limited is a professional China leading manufacturer of Alloy 24 (UNS S34565) open die forging parts and seamless rolled steel forged rings. Our company was established in and we have supplied clients around the world for more than 25 years. Our factory covers 80,000 sqm and has advanced forging and inspection facilities, including 2000-6000 tons hydraulic forging presses, 5-meter seamless rolling machines, and in-house quality testing labs. We provide a full range of service for Alloy 24 (UNS S34565) open die forging parts from steel melting, forging, heat treatment, machining to final testing. And all our products meet international standards and customer requirements.
What is Alloy 24 (UNS S34565)? Material Advantages & Performance
Alloy 24 (UNS S34565 / Werkstoff Nr. 1.4565) is a nitrogen and molybdenum alloyed super austenitic stainless steel with a nominal composition of 24% Cr - 17% Ni - 4.5% Mo - 0.5% N. Its PREN exceeds 40, calculated by: PREN = %Cr + 3.3 x %Mo + 16 x %N. The material meet standard set by ASTM A182, ASTM A479, EN 10088-3, and DIN Werkstoff Nr. 1.4565.
Alloy 24 has more great comprehensive performance compared to conventional stainless steel and duplex steel grades, so that it the best choice material for important industrial parts that must work well for a long time in harsh working conditions.
Main Performance Advantages of Alloy 24 (UNS S34565)
- Exceptional pitting & crevice corrosion resistance: They have excellent resistance to pitting corrosion, crevice corrosion, and stress corrosion cracking (SCC) in high-chloride media like seawater, desalination brine, and FGD slurry
- Superior weldability: They have excellent intergranular corrosion resistance after welding, and they don't need be heat treated after post-weld for most applications
- Higher mechanical strength: They are stronger than conventional 300-series austenitic't stainless steels (Rm ≥800 MPa), and can work steadily even at elevated temperatures up to 400°C
- Broad acid resistance: They have excellent resistance to sulfuric acid, nitric acid, and organic acids, and they are the best choice material for harsh chemical processing environments
Why PREN matters for material selection: The PREN value is the most commonly used index to judge how well a metal resists small pitting corrosion.
In general, a PREN value above 40 is the lowest level needed for safe, long‑term use in natural seawater (about 19,000 ppm chloride) and harsh industrial environments.Alloy 24 normally has a PREN value of around 47, which is well above this requirement and provides a large safety buffer.Alloy 24 vs. Common Corrosion-Resistant Alloys
This comparison helps engineers and procurement professionals make optimal material selections:
| Alloy | UNS | PREN | Rm (MPa) | Limitation | Alloy 24 Advantage |
|---|---|---|---|---|---|
| 316L | S31603 | ~24 | ≥485 | Poor pitting/SCC in high Cl media | 3x corrosion resistance |
| 2205 Duplex | S32205 | ~35 | ≥620 | Limited SCC in extreme seawater | Better weldability, higher cryogenic toughness |
| 254SMO | S31254 | ~43 | ≥650 | Lower strength, less N alloying | Higher Rm (≥800), more cost-effective |
| Alloy 625 | N06625 | ~51 | ≥827 | Significantly higher cost (Ni-base) | 40-60% lower material cost |
| Hastelloy C-276 | N10276 | ~69 | ≥690 | Very high cost, overkill for most Cl environments | Far more economical when PREN >40 suffices |
| Alloy 24 | S34565 | >40 (~47) | ≥800 | - | Best balance: corrosion + strength + cost |
Full Range of Alloy 24 (UNS S34565) Forged Product Forms
We manufacture custom UNS S34565 forged parts in a full range of shapes and specifications, and they all meet ASTM, EN, DIN, API and other international standards. Our main product range (see our main product lines):
1. Forged Bars & Rods
We make all kinds of forged bars from UNS S34565 ,including round bars, square bars, flat bars, rectangular bars and step bars.The maximum diameter of the parts is up to 2 meters, and the weight is up to 30 tons. They are the best choice material for shaft manufacturing, structural parts and custom machining blanks.
2. Seamless Rolled Forged Rings
We make many types of seamless rolled rings from Alloy 24 , including contoured rings, gear rings and flange blanks.The maximum outer diameter is up to 6 meters, and the weight is up to 30 tons. They are the best choice material for valve seats, bearing races, pressure vessel flanges and rotating parts.
3. Forged Shafts & Rotating Components
We provide custom UNS S34565 forged shafts, including turbine rotor shafts, marine propulsion shafts, valve spindles, pump shafts, and splined drive shafts. And their maximum length is up to 15 meters, diameter is up to 1800mm. We test every piece by ultrasonic testing to make sure all of them have high quality.
4. Custom Forged Components
- Alloy 24 forged hubs, housings, shells, sleeves, bushes, cases and hollow bars
- UNS S34565 forged discs, disks, blocks, plates, flanges and boss blanks
- Alloy 24 forged pipes, tubes, tubing shells, casings, barrels for pressure systems
- we can custom forged parts based on clients drawings and requirements for special applications.
Forged bars: the max diameter is up to 2m and wight is up to 30 tons. Seamless rings: the diameter is up to 6m and the weight is up to 30 tons. Shafts: the diameter is up to 15m. All products are tested by UT. Presses: 2000-6000 tons. Ring rolling: 1-5 meters. See our 8-step process →
Alloy 24 (UNS S34565) Forging Process Flow
All products are controlled in a strict, standardized 8-step forging process to make sure they have the highest quality .
- Raw Material Selection & Inspection: We buy the premium Alloy 24 (UNS S34565) ingots from certified suppliers, all the materials have great chemical composition and mechanical property pre-inspection
- Steel Melting & Refining: Electric arc furnace (EAF) + ladle refining (LF) + vacuum degassing (VD) as standard; electroslag remelting (ESR) is available for critical applications
- Open Die Forging: Forged on 2000-6000 tons hydraulic presses, with the minimum forging ratio of 3:1 to make sure the material has consistent distribution.
- Seamless Ring Rolling (if applicable): Rolled on 1-5 meter seamless rolling machines for precise ring dimensions and consistent grain distribution.
- Heat Treatment: Solution annealing (1100-1180°C) + rapid water quenching to make sure the material can strongly resistant to corrosion and have great mechanical properties
- Rough/Fine Machining (optional): They are made by In-house CNC machining so that they meet tolerance requirements up to IT6
- Full-Set Quality Inspection: 100% visual inspection , dimension test, UT, PT, MPT test; chemical analysis, tensile, impact, hardness, metallographic test
- Certification & Packaging: Provide EN 10204 3.1/3.2 certificate , anti-corrosion packaging for global shipping
Customization Capabilities for Alloy 24 (UNS S34565) Forgings
We offer a full range of customization services for Alloy 24 (UNS S34565) forged parts:
Dimensions & Tolerances
- Custom sizes: 30KG to 30 tons
- Tolerances: ISO 2768-mK
- CNC machining: up to IT6
Heat Treatment
- Solution annealing (1100-1180°C)
- Quenching & tempering
- Stress relieving
- Custom heat treatment cycles
Surface Treatment
- Shot blasting
- Pickling & passivation
- Polishing (Ra ≤ 0.8 um available)
- Anti-corrosion coating
Certifications
- ISO 9001:2015 certified
- EN 10204 3.1/3.2
- Third-party inspection: TUV, DNV, ABS, BV, GL, LR, RMRS, RINA
- Products meet API 6A, NACE MR0175/ISO 15156 requirements
- Custom third-party inspection
Industry Applications & Global Project Case Studies
Our high-performance Alloy 24 (UNS S34565) forged parts are used in important industrial sectors across Europe, North America, the Middle East, Southeast Asia and Australia:
1. Valve Manufacturing Industry
We supply custom UNS S34565 forged valve parts for valve manufacturers in Germany, Italy, the USA, and China. These parts include valve balls, valve bonnets, valve bodies, valve stems, valve closures, valve seat rings, valve cores, and valve discs. These parts are used for H-type two-way/one-way back pressure valves, ball valves, check valves, gate valves, and cryogenic high-performance butterfly valves (HPBV). All of them have stable performance in corrosive medium control systems for chemical plants, power stations and oil and gas facilities, and they all meet TUV and API 6A certification.
2. Chemical Process Industry (CPI) & Pharmaceutical
Project Case: Southeast Asia — Large-Scale Petrochemical (Singapore)
We supplied custom Alloy 24 (UNS S34565) forged reactor nozzles, heat exchanger tube sheets, baffle plates and channel flanges for a large-scale petrochemical project in Singapore. The client had equipment breakdowns and traditional 316L parts wore out quickly in high-temperature (160°C), high-pressure corrosive media with high chloride content. Our Alloy 24 forgings are used to solve the corrosion and cracking issues, which makes the equipment last more than three times longer. All products passed full NDT and third-party inspection.
Our UNS S34565 forgings are also used in food processing and pharmaceutical production equipment that need strict corrosion resistance, hygiene standards and cleanability.
3. Power Generation & Flue Gas Desulphurisation (FGD)
Project Case: Germany & Poland (EU) — Coal-Fired Power Plants
We provided UNS S34565 forged valve bodies, seat rings and slurry pump components for 6 coal-fired power plants in Germany and Poland.All products fully meet DIN EN 10228-3 standard. These parts are used in slurry circulation pipelines of FGD systems.The working conditions include chloride up to 35,000 ppm, pH 1–3, and erosion from solid particles. Our Alloy 24 forgings have been working well for more than 8 years without corrosion failure,which help client reduce the maintenance costs and downtime.
Our Alloy 24 forgings are also used for turbine rotor shafts, generator parts and other important power generation equipment for thermal power, nuclear power and renewable energy projects around the world.
4. Marine & Shipbuilding Industry
Project Case: Europe & South Korea — International Shipbuilding
We made custom Alloy 24 forged marine propulsion shafts, propeller shafts, seawater cooling system piping shells and valve parts for international shipbuilding enterprises in Germany and South Korea, and all parts meet DNV and ABS classification society certification. These parts are installed on large ocean-going cargo vessels and offshore engineering ships, which have to work in high-salinity seawater and cyclic stress for a long time. Our UNS S34565 forgings have ultra-strong resistance to stress corrosion cracking and pitting corrosion, and they all fully meet EU and North American marine equipment standards.
Our Alloy 24 forgings are also the best choice material for seawater desalination plants, offshore platforms, and coastal power stations in the Middle East and Australia.
5. Nuclear Power Industry
Project Case: China — Domestic Nuclear Power Plants
We supplied UNS S34565 forged nuclear reactor coolant pump casings, seal chamber components and impeller blanks for domestic nuclear power plant projects in China and nuclear power projects in Europe. All parts are made based on nuclear-grade forging standards, with a minimum forging ratio of 3:1, premium ESR melting process, and full-process quality traceability. The parts passed full non-destructive testing, mechanical property testing and chemical analysis, and they all meet the stringent safety and reliability requirements of nuclear-grade equipment.
6. Oil & Gas Upstream & Downstream
Project Case: Saudi Arabia, UAE & Kuwait (Middle East) — Onshore & Offshore Oilfields
We produced custom UNS S34565 forged downhole drilling tool shafts, mud motor splined drive shafts, electric submersible pump (ESP) parts and wellhead valve parts for onshore and offshore oilfield projects in Saudi Arabia, UAE and Kuwait. They all meet API 6A and NACE MR0175 standards for sour service environments. They are used in extreme downhole environments with high sulfur content, high chloride concentration, high pressure and high temperature. Our Alloy 24 forgings greatly reduce the equipment failure rate, extend the maintenance cycle, and help the client reduce annual O&M costs by more than 20%.
7. General Industrial Applications
Our Alloy 24 (UNS S34565) forged parts are also used for turbomachinery and centrifugal compressor impellers, all parts of pump (casings, impellers, shafts, wear rings), pressure vessel and reactor nozzles, venturi cone meter bodies, and custom parts for pulp and paper, mining and environmental protection industries.
Jiangsu Liangyi has supplied Alloy 24 (UNS S34565) forgings to more than50 countries across seven major industry sectors,including valve manufacturing, chemical processing, FGD power generation, marine and shipbuilding, nuclear power, oil and gas, and general industrial conditions. They have been used in many projects in Germany, Poland, Singapore, South Korea, Saudi Arabia, UAE, Kuwait, China, Australia, and other countries around the world.
Alloy 24 (UNS S34565) Chemical Composition
Our UNS S34565 forging material strictly meet ASTM A182, ASTM A479, and EN 10088-3:
| Element | Symbol | Content (wt%) | Role |
|---|---|---|---|
| Iron | Fe | Balance (43.2-51.6) | Base element |
| Chromium | Cr | 23.0-25.0 | Corrosion resistance, passive film |
| Nickel | Ni | 16.0-18.0 | Austenite stabilizer, toughness |
| Manganese | Mn | 5.0-7.0 | N solubility, austenite stabilizer |
| Molybdenum | Mo | 4.0-5.0 | Pitting resistance (3.3x in PREN) |
| Silicon | Si | 0-1.0 | Deoxidizer |
| Nitrogen | N | 0.40-0.60 | Strength, PREN (16x factor) |
| Niobium | Nb | 0-0.10 | Grain refinement |
| Carbon | C | 0-0.030 | Low to prevent sensitization |
| Phosphorus | P | 0-0.030 | Impurity - minimized |
| Sulfur | S | 0-0.010 | Impurity - minimized |
Using typical mid-range values (24% Cr, 4.5% Mo, 0.5% N):
PREN = 24 + (3.3 x 4.5) + (16 x 0.5) = 24 + 14.85 + 8.0 = 46.85
This figure is significantly higher than the minimum requirement of 40 for seawater service, ranking Alloy 24 among the top-tier corrosion-resistant austenitic stainless steels.
Mechanical Properties, Heat Treatment & Standards
International Standards Compliance
- ASTM A788/A788M — Steel Forgings, General Requirements
- ASTM A182/A182M — Forged Alloy & Stainless Steel Fittings
- ASTM A479/A479M — Stainless Steel Bars & Shapes
- EN 10228-3 — NDT of Steel Forgings (UT)
- EN 10088-3 — Stainless Steels, Technical Delivery
- API 6A / API 6D — Oil & Gas Equipment
- NACE MR0175/ISO 15156 — Sour Service Materials
- NORSOK M-630 — Subsea Piping Materials
- DNV, ABS, BV, GL, LR, RMRS, RINA — Classification Societies
Mechanical Properties — Solution Annealed Condition
| Property | Value | Condition |
|---|---|---|
| Yield Strength (Rp0.2) | ≥420 MPa | Room temp. / ASTM A370 |
| Yield Strength at 400°C | ≥240 MPa | Elevated temp. |
| Tensile Strength (Rm) | ≥800 MPa | Room temp. / ASTM A370 |
| Elongation (A5) | ≥40% | Room temp. |
| Charpy Impact (Longitudinal) | ≥120 J | Room temp., t >10mm |
| Charpy Impact (Transverse) | ≥90 J | Room temp., t >10mm |
| Hardness | ≤300 HB | Brinell |
| Forging Ratio | ≥3:1 | All forgings |
All UNS S34565 forgings are produced by a minimum forging ratio of 3:1, which make sure they all have a great distribution, improved fatigue resistance and extended lifetime. meanwhile the internal porosity is eliminated.
Equivalent International Specifications for UNS S34565
UNS S34565 (Alloy 24) is recognized across multiple international standard systems:
| Standard | Designation | Product Form |
|---|---|---|
| UNS (USA) | S34565 | All forms |
| DIN / Werkstoff Nr. | 1.4565 | All forms |
| ASTM A182 | F65 | Forgings, fittings, flanges |
| ASTM A479 | S34565 | Bars & shapes |
| ASTM A240 | S34565 | Plate, sheet, strip |
| EN 10088-3 | X2CrNiMnMoN24-17-6-5 | Semi-finished, bars |
| NORSOK M-630 | Referenced | Subsea components |
| VdTUV (Germany) | Werkstoffblatt 555 | Pressure equipment |
For North American projects, please specify ASTM A182 F65 (forgings) or ASTM A479 S34565 (bars). For European projects, please choose EN 10088-3 / 1.4565. For offshore and subsea applications, please refer to NORSOK M-630. For German pressure equipment, please refer to VdTUV Werkstoffblatt 555. Jiangsu Liangyi provide these products that meet any of these standards ,and the full corresponding documentation are all available based on clients requirement.
Manufacturing Process & Quality Assurance
Premium Melting Process
- Standard: Electric arc furnace (EAF) + ladle refining (LF) + vacuum degassing (VD)
- Premium option: Electroslag remelting (ESR) for critical nuclear, offshore, and aerospace applications
Full-Set Inspection & Certification
Complete in-house quality lab with full-set inspection facilities:
- NDT: 100% visual inspection, dimension test, UT (EN 10228-3), PT, MPT
- Lab Testing: Chemical analysis (OES), tensile, impact, hardness, creep, metallography
All forgings are supplied with EN 10204 3.1 MTC as standard. EN 10204 3.2 witness inspection by third-party bodies such as TUV, DNV, BV, ABS, GL, Lloyd's Register, RMRS, RINA is available upon request, and all parts are traceable from melt to delivery.
100% UT + PT/MPT → Full chemical analysis → Complete mechanical testing → Metallographic exam → EN 10204 3.1 MTC (3.2 available) → Anti-corrosion packaging → Full traceability.
Why Choose Jiangsu Liangyi for Alloy 24 Forgings?
more than 25 Years Experience
Established in ver 25 years.
Full In-House Capability
Our factory covers 80,000 sqm and have advanced equipment including 2000-6000 ton presses, 1-5m ring rolling machines, CNC centers, and full NDT/lab testing. We provide One-stop service from melting to delivery.
50+ Countries Served
We have supplied the clients from Germany, USA, South Korea, Singapore, Saudi Arabia, UAE, Australia and more than 50 countries .
Multi-Standard Certification
ISO 9001:2015 certified. EN 10204 3.1/3.2 available. Third-party witness inspection by TUV, DNV, ABS, BV, GL, Lloyd's and other classification societies available upon request. Products meet API 6A and NACE MR0175 requirements.
Factory-Direct Pricing
No middleman is involved. all parts are supplied with competitive price and the terms including FOB, CIF, DDP are available.
Fast Response & Delivery
Professional team responds within 24 hours. Standard lead time 25-35 days, expedited service available.
Frequently Asked Questions (FAQ)
The UNS designation is UNS S34565, also known as Werkstoff Nr. 1.4565. It is standardized under ASTM A182 (as F65), ASTM A479, and EN 10088-3.
It is used for critical parts in harsh corrosive environments, such as FGD valve and pump parts, marine seawater equipment, chemical reactors, nuclear power parts, oil and gas downhole tools, and desalination equipment. See our detailed case studies.
It has excellent resistance to pitting, crevice corrosion, and SCC in high-chloride media. It has been working well in FGD slurry with 35,000 ppm chloride (pH 1-3) for more than years without failure. and it is the best choice material for seawater, desalination brine, sulfuric and nitric acids.
It has three times of corrosion resistance and the much higher strength compared with 316L.. It has better SCC resistance and is easier to be welded compared with 2205. It has Higher Rm (≥800 vs ≥650 MPa) compared with 254SMO. .And it is far more economical when PREN >40 suffices compared with C-276: . See full comparison table.
Yes. Custom open die forgings and seamless rolled rings from 30KG to 30 tons per piece. All parts are made based on clients drawings, specs, and quantity. We also offer other material grades.
25-35 days for small or medium batches. 45-60 days for large parts. and we can speed up production for urgent orders. Contact us for project-specific timelines.
All parts are supplied with EN 10204 3.1 MTC. EN 10204 3.2 witness inspection by TUV, DNV, BV, ABS, GL, LR, RMRS, RINA is available upon request. Products used for Oil and gas meet the requirements of API 6A, NACE MR0175 and ISO 15156. See quality assurance.
Bars: max diameter 2m / 30 tons. Rings: max OD 6m / 30 tons. Shafts: max length15m / diameter up to 1800mm. Equipment: 2000-6000 ton presses + 1-5m ring rolling. All parts are tested by UT. See product range.
Standard: EAF + LF + VD. Premium: ESR for nuclear, offshore, critical applications. Full documentation are available per EN 10204. See manufacturing details.
UNS S34565 = Werkstoff Nr. 1.4565 = ASTM A182 F65 = EN 10088-3 X2CrNiMnMoN24-17-6-5. Also listed in NORSOK M-630 and VdTUV 555. See full cross-reference table.
Get a Custom Quotation for Alloy 24 (UNS S34565) Forged Parts
Jiangsu Liangyi is a reliable China manufacturer of high-quality Alloy 24 (UNS S34565) forged parts, with over 25 years of experience serving clients from more than 50 countries. We provide custom forging solutions with competitive price and high quality .
Whether you need standard forged bars, seamless rolled rings, or custom parts, we will provide one-stop service from melting to final machining and testing.
Contact Details
Email: sales@jnmtforgedparts.com
Phone / WhatsApp: +86-135-8506-7993
Website: www.jnmtforgedparts.com
Factory: Chengchang Industry Park, Jiangyin City, Jiangsu Province, China 214400
Send your drawings, material specs, and quantity requirements via email or WhatsApp. Our team will reply with a detailed quotation and technical solution within 24 hours.