Certifications: ISO 9001, API 6A, ASME SB-164, EN 10204-3.1/3.2, ABS, DNV, BV
Lead Time: 45 days (standard) / 60 days (fully custom)
Shipping: FOB Shanghai / CIF main ports; USA, EU, UK, Australia, Middle East
Manufacturer: Jiangsu Liangyi, Jiangyin City, Jiangsu, China — founded 1984
Jiangsu Liangyi is a leading China manufacturer of Monel 400 (UNS N04400) forging with over 40 years of experience. Our main products are custom Alloy 400 open-die forging products and seamless rolled forged rings which are widely used in marine, chemical, nuclear, oil & gas industries across the USA, EU (Germany, France, Italy), UK, Australia, and Middle East (Saudi Arabia, UAE, Qatar).
Definition: Monel 400 (UNS N04400, also called Alloy 400 or W.Nr. 2.4360) is a nickel-copper solid-solution alloy which contains 63–70% nickel and 28–34% copper, according to ASTM B164 / ASME SB-164. It is one of the most widely used corrosion-resistant alloys in heavy industry, originally developed by the International Nickel Company and named after company founder Ambrose Monell.
Main characteristics that make Monel 400 the best choice for many industries:
Outstanding resistance to seawater and chloride environments — corrosion rate < 0.025 mm/year in seawater
Excellent resistance to hydrofluoric acid (below 80 °C), alkaline solutions, and reducing acid media
High strength and toughness across a wide temperature range — from cryogenic service to 500 °C (932 °F)
Single-phase solid-solution microstructure — no sensitisation risk during welding or heat treatment
Good weldability (GTAW, GMAW, SMAW) and machinability in the annealed condition
Monel 400 (UNS N04400) Forged Product Range
We manufacture a wide range of Monel 400 forged parts in standard and customized sizes for different global industries.
Power Generation: Turbines, turbomachinery, heat exchangers, boiler parts — ASTM B164
General Engineering: Valves, mechanical seal discs, custom heavy-duty machine forgings
Production standards: Marine — ABS Rules | Oil & Gas — API 6A / ISO 13628-4 | Nuclear — ASME Section III | Chemical — ASTM B164
Monel 400 Forgings — Global Application Case Studies
Forgings shipped to over 50 countries:
Marine (Australia): 400 Monel 400 propeller shafts supplied to an offshore fishing fleet. Seawater corrosion rate < 0.025 mm/year; maintenance cost reduced 60%. ABS certified,as per AS/NZS. Production time is only 30 days.
Chemical Plant (Germany): Pressure vessel nozzles and valve components for a famous 500 HF acid plant. Zero leakage over 5+ years use; In accordance with EU industrial safety standard.
Oil & Gas (Middle East): Wellhead spools and pump shafts for an oilfield company. Rated 500 °C / high pressure; delivered in 45 days per API 6A.
Nuclear Power (UK): UNS N04400 forged impellers for a light water reactor. DNV inspected; 3+ years safe operation; UKCA marked.
Power Generation (USA): Alloy 400 seamless rolled rings and heat exchanger tube sheets for a famous 500 thermal power company. Heat exchanger efficiency improved 15%.
Choosing Monel 400 or Monel K-500 depends on required strength and weldability:
Monel 400 (UNS N04400) vs. Monel K-500 (UNS N05500)
Property
Monel 400 (UNS N04400)
Monel K-500 (UNS N05500)
Ni Content
63–70%
63–70%
Cu Content
28–34%
27–33%
Al + Ti additions
None
Al 2.3–3.15%; Ti 0.35–0.85%
Tensile Strength
517–620 MPa
900–1100 MPa
Yield Strength
172–345 MPa
620–760 MPa
Hardening Mechanism
Cold work only
Age-hardening (precipitation)
Weldability
Excellent
Good (post-weld age required)
Corrosion Resistance
Excellent
Excellent (similar)
Typical Standard
ASTM B164
ASTM B865
Best For
Valves, heat exchangers, pump casings
High-torque shafts, springs
Relative Cost
Lower
Higher (~20–30%)
How Monel 400 Forgings Are Manufactured — Step-by-Step Process
Jiangsu Liangyi follows below 10-step process strictly when making each Monel 400 forging to make sure full traceability and they can meet the international standards.
Raw Material Verification: PMI (Positive Material Identification) test the chemistry of ASTM B164-certified billet and mill certificate. Heat number will be written down so that it could be traced back to its source.
Billet Heating: Billets heated to 900–1150 °C in a sulfur-free furnace atmosphere to ensure uniform temperature distribution and prevent surface contamination.
Open-Die Forging / Seamless Ring Rolling: Correct reduction ratios can help to get continuous grain flow, eliminate porosity and ensure mechanical property uniformity throughout the cross-section.
Full Annealing Heat Treatment: Annealed at 870–982 °C (1600–1800 °F) in a sulfur-free atmosphere to complete recrystallisation. Stress relieved at 538–566 °C for 1–2 hours as per need.
Rough Machining & Size Inspection: Near-net-shape machining and tested as per clients' drawing.
Non-Destructive Testing (NDT): Ultrasonic testing (UT according to ASTM A388) + surface crack detection (MT or PT). Results recorded in the test certificate.
Mechanical Testing: Tensile, yield, elongation and Brinell/Rockwell hardness tests on samples from the same heat per ASTM B164.
Chemical Analysis: Complete spectral analysis makes sure that the Ni content is 63-70%, the Cu content is 28-34%, and the contents of all trace elements meet the ASTM B164 standard.
Third-Party Inspection & Certification: Inspected by TUV, DNV, ABS or BV as specified. EN 10204-3.1 or 3.2 certification issued.
Export Packing & Shipment: Export packing as per ISPM 15 . FOB Shanghai or CIF main ports; 45–60 days delivery.
Monel 400 (UNS N04400) Heat Treatment
We strictly control heat treatment for all Monel 400 open-die forgings to make sure best mechanical properties.
Full Annealing: 870–982 °C (1600–1800 °F) in a sulfur-free atmosphere. Lower end of range makes finer grain size.
Stress Relieving: 538–566 °C (1000–1050 °F) for 1–2 hours — relieves residual forging stresses without recrystallisation.
Open-Die Forging & Seamless Ring Rolling: The right forging temperature ensures grain-flow continuity and structural integrity in all Alloy 400 forged rings.
Quality Assurance and Certifications
Every batch of Monel 400 forged parts will undergo strict quality control with its inspection certification. Jiangsu Liangyi is an ISO 9001-certified manufacturer.
Monel 400 Forged Parts — Full Test Certificate includes
Heat number and melting method
Dimensional inspection results
Full heat treatment process record
Chemical composition analysis
Mechanical test results (hardness, tensile, yield, elongation)
Ultrasonic testing (UT) and surface crack detection (MT/PT) results
Surface inspection
Client's other additional tests per drawing or purchase order
Why Choose Jiangsu Liangyi as Your Monel 400 Forgings Manufacturer?
⭐ 40+ Years of Experience (since 1984): We have a lot of experience with Monel 400 open-die forging for clients in more than 50 countries.
⭐ Fully Custom Production: We can make Monel 400 forgings as per your drawings — any shape, in any size.
⭐ Strict Quality Control: ISO 9001 certified; All tests are done in workshop and by a third-party inspection (TUV, DNV, ABS, BV).
⭐ On-Time Delivery: 45-day standard lead time; our teams will make sure on-time delivery to our clients in USA, EU, UK, Australia and Middle East.
⭐ Competitive Pricing: We are a direct manufacturer, so we can offer better price; We also offer competitive prices on high-quality Monel 400 forgings.
⭐ Full Traceability: EN 10204-3.1/3.2 certificates; heat traceability from melt to finished forging.
⭐ Professional Engineering Teams: Our engineers are experienced and professional, so they can help you choose the right material, check your drawings, and give you technical advice.
A: Monel 400 (UNS N04400, Alloy 400) is a nickel-copper solid-solution alloy which contains 63–70% nickel and 28–34% copper, according to ASTM B164 / ASME SB-164. It has great resistance in seawater (< 0.025 mm/year), hydrofluoric acid and alkaline environments, with a service temperature from cryogenic to 500 °C (932 °F).
Q: What are the physical properties of Monel 400?
A: Monel 400 (UNS N04400) physical properties are as below: Density 8.80 g/cm³ (0.318 lb/in³); Melting range 1300–1350 °C (2372–2462 °F); Thermal expansion coefficient 13.9 µm/m·°C (20–100 °C); Thermal conductivity 21.8 W/m·K at 20 °C; Specific heat 427 J/kg·K; Electrical resistivity 0.511 µΩ·m.
Q: How does Monel 400 work in corrosive media?
A: Monel 400 works well in seawater (corrosion rate < 0.025 mm/year), hydrofluoric acid (below 80 °C), dilute hydrochloric acid (room temperature), alkaline solutions (NaOH), and high-temperature steam up to 500 °C. It is not recommended for use in strong oxidising acids such as concentrated nitric acid or fuming sulfuric acid.
Q: What is the lead time for custom Monel 400 forgings?
A: Normally 45 days for standard sizes if stock raw material available, and 60 days for fully custom Monel 400 forgings. We make sure on-time delivery to our global customers in the USA, EU, UK, Australia and Middle East.
Q: Do Monel 400 forgings comply with ASME and API standards?
A: Yes. Our Monel 400 forgings are according to ASTM B164 / ASME SB-164, API 6A (oil and gas), ASME Section III (nuclear), and ABS Rules (marine structures).
Q: Can you accept third-party inspection?
A: Yes. We can do third-party inspection by TUV, DNV, ABS, BV (Bureau Veritas) and Lloyd's Register. A complete EN 10204-3.2 Inspection Certificate is provided with each shipment.
Q: What makes the difference between Monel 400 and Monel K-500?
A: Monel 400 (UNS N04400) is an annealed solid-solution alloy (tensile strength 517–620 MPa) with excellent weldability. Monel K-500 (UNS N05500) adds Al (2.3–3.15%) and Ti (0.35–0.85%) for age-hardening, raising tensile strength to 900–1100 MPa. Choose Monel 400 when weldability and cost are priorities; choose Monel K-500 when higher strength is required.
Q: How is Monel 400 forging manufactured step by step?
A: Monel 400 open-die forging is produced in 10 steps: (1) PMI raw material verification; (2) Heating to 900–1150 °C; (3) Open-die forging or ring rolling; (4) Annealing at 870–982 °C; (5) Rough machining & CMM inspection; (6) UT + MT/PT NDT testing; (7) Mechanical testing per ASTM B164; (8) Chemical analysis; (9) Third-party inspection & EN 10204-3.2 certificate; (10) Export packing and global shipment in 45–60 days.
Q: What kind of heat treatment is suitable for Monel 400 forgings?
A: Monel 400 forgings are full annealed at 870–982 °C (1600–1800 °F) in an atmosphere without sulfur so that they can fully recrystallize and be resistant to corrosion as possible. Stress relieving at 538–566 °C (1000–1050 °F) for 1–2 hours is done when you need to reduce residual stresses without making the grains grow.
Monel 400 (UNS N04400) Forged Components — Global Supply
Jiangsu Liangyi is a trusted supplier of high-quality custom Monel 400 forgings all over the world. We are one of the biggest Monel 400 makers in China, and we ship to the USA, EU, UK, Australia, the Middle East and other places around the world.
