Material Grade Specification

Monel 400 Flanges — ASTM B564 UNS N04400

Monel 400 flange manufacturer, Mumbai. UNS N04400 Ni-Cu alloy, immune to chloride stress corrosion cracking, hydrofluoric acid service spec. Quote in 30 min.

Material Specification & Overview

Monel 400 (UNS N04400) is a nickel-copper alloy exhibiting high strength, excellent weldability, and exceptional resistance to rapidly flowing seawater, hydrofluoric acid, and alkalis.

UNS DesignationN04400
Governing StandardASTM B564 / ASME SB-564 UNS N04400

Chemical Composition (wt %)

Governing specification limits per ASTM / ASME standards. Actual values provided on EN 10204 3.1 MTC.

ElementSpecification Limit / Composition
Nickel (Ni)63.0% min
Copper (Cu)28.0 - 34.0%
Iron (Fe)2.5% max
Manganese (Mn)2.0% max

Mechanical Properties

PropertySpecification Limit
Yield Strength240 MPa (35 ksi) min
Tensile Strength480 - 620 MPa
Service Temp RangeCryogenic to 480°C

Pressure-Temperature Rating Reference

Service TempClass 150Class 300Class 600Class 900
Ambient (-29 to 38°C)290 psi750 psi1500 psi2250 psi

Primary Industry Applications

Hydrofluoric (HF) acid alkylation units in oil refineries
Marine propeller shafts and seawater piping systems
Brine heaters and evaporators in desalination plants
Caustic soda concentration plant equipment

Forging, Heat Treatment & Quality Inspection Protocols

Forging & Thermal Processing

Flanges in Monel 400 Flanges are manufactured via precision closed-die or open-die forging to establish continuous metallurgical grain flow along the flange hub and neck contour. Raw billets are heated in calibrated gas-fired furnaces under strictly controlled soak temperatures to eliminate microstructural defects.

Depending on the alloy grade, components undergo certified thermal conditioning: normalizing for carbon steels (A105N, A350 LF2), rapid water quench solution annealing at 1040°C–1120°C for stainless and duplex grades, or controlled aging for nickel superalloys. This ensures exceptional notch toughness, yield strength, and resistance to stress corrosion cracking.

Dimensional Tolerances & Certification

Final machining is executed on heavy-duty CNC turning centers to guarantee precise raised face, flat face, or ring type joint (RTJ) dimensions compliant with ASME B16.5, ASME B16.47, DIN, or EN 1092-1 standards. Gasket contact surfaces receive spiral or concentric serrations strictly controlled between 125 and 250 µin Ra.

Every production heat is issued with an EN 10204 Type 3.1 inspection certificate containing full heat chemistry, mechanical tensile test data, and Charpy impact values. Independent Third-Party Inspection (TPI) by Lloyd's, BV, DNV-GL, TÜV, and SGS is readily accommodated for global EPC and refinery contracts.

Related Products & Industry Guides

Frequently Asked Procurement Questions

Q: Is Monel 400 resistant to Hydrofluoric (HF) acid?

A: Yes. Monel 400 is the standard metallic material of choice for HF acid service up to boiling temperatures, provided aeration is controlled.

Direct Factory Pricing

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