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Monel K500 Flanges Supplier in Mumbai, India – ASTM B564 UNS N05500
Nicorex Alloys is an ISO 9001 and ISO 14001 certified importer, stockist, and supplier of Monel K500 flanges based in Mumbai, India. We provide these precipitation-hardened nickel-copper flanges in compliance with the ASTM B564 and ASTM B865 standards.
Alloy K-500 (UNS N05500, Werkstoff 2.4375) is a high-strength nickel-copper forging alloy that gains its mechanical advantage through a controlled age-hardening process. By adding aluminium (2.30–3.15%) and titanium (0.35–0.85%) to the Monel 400 nickel-copper base and heating to 593°C, the alloy precipitates submicroscopic Ni₃(Ti, Al) gamma-prime particles throughout its matrix. This provides a higher yield strength and good corrosion resistance. Monel K500 is the only precipitation-hardenable nickel-copper alloy widely specified for high-strength marine and subsea flange connections. The alloy is non-magnetic below –100°C (–150°F), a property critical for subsea MWD/LWD tools and magnetic-sensitive instrumentation. Minimum tensile strength reaches 1035 MPa (150 ksi) in the aged condition, with yield strength at 690 MPa (100 ksi).
Nickel Alloy K500 flanges are stocked in Weld Neck (WNRF), Blind (BLRF), Socket Weld (SWRF), Threaded, Ring Type Joint (RTJ), and Spectacle Blind configurations. Sizes range from NPS 1/2” to 24” per ASME B16.5, in pressure classes from 150 through 2500, with RF, FF, and RTJ face types. Key industries include marine propulsion, subsea oil and gas, sour service production, aerospace and defence, and process equipment.
Monel K500 Flanges Specifications
Technical specifications for UNS N05500 forged flanges, including standards, sizes, types, and other key details, are covered in the table below:
| Specification | ASTM B564 / ASME SB564; ASTM B865 / ASME SB865 |
|---|---|
| Flange Types | WNRF, BLRF, SWRF, Threaded, RTJ, Spectacle Blind |
| Size (ASME B16.5) | NPS 1/2” to NPS 24” |
| Pressure Classes | 150, 300, 400, 600, 900, 1500, 2500 |
| Face Types | RF, FF, RTJ |
| Dimensional Standards | ASME B16.5, B16.47, MSS SP-44, EN 1092-1, JIS B2220, BS 4504 |
| Supply Conditions | Annealed (soft); Age-Hardened (precipitation treated); Hot-Finished & Aged |
Chemical Composition of Monel K500 Flanges
Chemical composition as per ASTM B865 for UNS N05500 and its key alloying elements are provided in the table below:
| Element | Nickel (Ni) + Cobalt (Co) | Copper (Cu) | Aluminium (Al) | Titanium (Ti) | Iron (Fe) | Manganese (Mn) | Carbon (C) | Silicon (Si) | Sulfur (S) |
|---|---|---|---|---|---|---|---|---|---|
| WT% | 63.0 min | 27.0 – 33.0 | 2.30 – 3.15 | 0.35 – 0.85 | 2.0 max | 1.5 max | 0.25 max | 0.5 max | 0.010 max |
Aluminium and titanium are the critical additions that separate K500 from Monel 400. During controlled ageing (593°C / 16 hours, furnace cool at 8–14°C/hr to 482°C), submicroscopic Ni₃(Ti, Al) gamma-prime precipitates form throughout the matrix. Yield strength rises from ~240 MPa (annealed) to ~690 MPa (aged).
Mechanical Properties of Monel K500 Flanges – Annealed and Age-Hardened
Monel K500 flanges are shipped in the annealed or age-hardened condition. Ageing triples the yield strength. Key mechanical properties in both conditions are provided in the tables below:
Annealed Condition (ASTM B865):
| Property (Annealed) | Tensile Strength (min) | Yield 0.2% Offset (min) | Elongation (min) | Hardness |
|---|---|---|---|---|
| Value | 655 MPa (95 ksi) | 240 MPa (35 ksi) | 20% | 140–180 HBW |
Age-Hardened Condition (ASTM B865):
| Property (Aged) | Tensile Strength (min) | Yield 0.2% Offset (min) | Elongation (min) | Hardness |
|---|---|---|---|---|
| Value | 1035 MPa (150 ksi) | 690 MPa (100 ksi) | 15% | 265–350 HBW (24–38 HRC) |
NACE MR0175 limits K500 hardness to 35 HRC max for sour gas. Specify NACE compliance at the order stage so the ageing cycle targets 24–35 HRC. Always specify the condition (annealed or aged); an annealed K500 flange has similar strength to Monel 400.
Monel Alloy K500 Flanges Equivalent Grades
The standard equivalent designation for Monel K500 flanges is UNS N05500, and its Werkstoff Nr. is 2.4375. Some other international designations are covered below:
| UNS | Werkstoff | DIN | JIS |
|---|---|---|---|
| N05500 | 2.4375 | 17743, 17750, 17752–17754 | NW 5500 |
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Types of Alloy K-500 Flanges Available
K500 flanges are forged as per ASTM B564/B865, typically supplied age-hardened. The following types of Monel K500 flanges are available at Nicorex Alloys:
Monel K500 Weld Neck Flanges (WNRF)
Monel K500 Blind Flanges (BLRF)
Monel K500 Ring Type Joint Flanges (RTJ)
Monel K500 Socket Weld Flanges (SWRF)
Monel K500 Threaded Flanges
Monel K500 Spectacle Blind Flanges
Alloy K500 Slip-On Flanges (SORF)
Monel K500 Alloy Lap Joint Flanges
Monel K500 Long Weld Neck Flanges (LWNRF)
Monel K500 Reducing Flanges
Monel K500 Orifice Flanges
Pressure-Temperature Ratings for Monel K500 Flanges
K500 falls under ASME B16.5 Material Group 1.4, same as Monel 400, because B16.5 ratings use minimum (annealed) properties. The maximum design is 538°C (1000°F). However, the aged body provides a higher structural safety margin as actual yield (690+ MPa) far exceeds Group 1.4 minimums. Above 593°C, precipitates overage and dissolve, reverting strength toward annealed levels.
Monel K500 Flanges Applications
Monel K500 flanges are in 5 key applications where piping connections require both the corrosion resistance of nickel-copper alloys and mechanical strength exceeding what Monel 400 can provide:
- Pump suction and discharge flanges, impeller casing connections, and sea chest piping in high-velocity seawater.
- Subsea wellhead connectors, tree valve bonnets, and manifold piping.
- Wellhead flanges, choke valve connections, and produced water injection manifold joints. The alloy is particularly suitable for offshore sour gas platforms where both H₂S exposure and marine atmospheric corrosion are concurrent failure risks.
- Aircraft fuel system connections, hydraulic manifolds, and electronic housing joints. Naval applications: torpedo propulsion piping, submarine seawater systems, and degaussing circuit connections.
- Pump bonnet connections, valve body-to-bonnet joints, and compressor casing flanges for corrosive fluids under high cyclic loads. Pulp and paper mixing shaft flanges resist organic acids and caustic soda at high wear.
How to Order Monel K500 Flanges From Nicorex Alloys
To receive an accurate quotation for Monel K500 flanges, include the following details:
- Flange Type : (WNRF, BLRF, SWRF, Threaded, RTJ, Spectacle Blind)
- Size (NPS)
- Pressure Class : (150, 300, 600, 900, 1500, 2500)
- Face Type : (RF, FF, RTJ — specify ring number if RTJ)
- Schedule / Bore (for weld neck and socket weld flanges)
- Material Grade: ASTM B564 UNS N05500 or ASTM B865 UNS N05500
- Supply Condition: Annealed OR Age-Hardened (CRITICAL — specify this)
- NACE MR0175 Compliance: Yes/No (if yes, hardness ≤35 HRC will be targeted)
- Quantity
- Testing / Certification Requirements (MTC 3.1, PMI, hardness test, NACE)
- Dimensional Standard (ASME B16.5, EN 1092-1, DIN, JIS)
- Packaging & Delivery Requirements
IMPORTANT: Always specify supply condition (annealed or age-hardened) and whether NACE MR0175 compliance is required. An unspecified order defaults to an age-hardened condition.
Frequently Asked Questions
What is the Difference Between ASTM B564 and ASTM B865 for K500?
B564 is a general nickel alloy forging spec covering many alloys. B865 is specified for precipitation-hardened UNS N05500 with detailed ageing procedure validation and dual-condition mechanical requirements.
Can K500 Flanges be Welded?
Yes, using ERNiCu-7 (Monel Filler Metal 60) for GTAW. Welding dissolves precipitates in the HAZ, reducing local strength to annealed levels (~240 MPa yield). Full restoration requires post-weld solution anneal at 982°C + re-ageing at 593°C, impractical for large field joints.
Why is K500 Non-Magnetic while Monel 400 is Magnetic?
Al and Ti additions shift the Curie temperature well below ambient. In aged condition, K500 has permeability <1.001 to below -100°C. Monel 400’s Curie temp sits at 21–49°C, causing slight ferromagnetism at room temperature.
What is the maximum service temperature for Monel K500 flanges?
ASME B16.5 rates K500 to 538°C (1000°F). Above 593°C, Ni₃(Ti, Al) precipitates overage and dissolves. For high-strength service above 480°C, consider Inconel 718 (rated to 704°C).
Does K500 have the Same Corrosion Resistance as Monel 400?
Substantially equivalent in most environments: seawater, HF, de-aerated H₂SO₄/HCl, and caustic soda. Aged K500 has a greater SCC tendency in aerated chloride solutions at elevated temperatures. Where high strength is not needed, Monel 400 is more reliable and cost-effective.
What Hardness is Required for Monel K500 Flanges in Sour Gas Service?
NACE MR0175/ISO 15156 limits the maximum hardness of precipitation-hardened Monel K500 to 35 HRC (approximately 310 HBW) for sour gas (H₂S) service. Standard age-hardening can produce hardness up to 38 HRC, so NACE-compliant ageing requires controlled parameters to target the 24–35 HRC range. This must be specified at the order stage so the supplier can adjust the ageing cycle accordingly.