Specifications
Surface Treatments
Certifications
- ISO 9001 - 2015 Certified
- PED 2014/68/EC
- NACE MR0175/ISO 15156-2
- NORSOK M-650
- DFAR
- MERKBLATT AD 2000 W2/W7/W10
Monel 400 Plate - UNS N04400, ASTM B127
Monel 400 plate (also Monel 400 plates, Alloy 400 plate, UNS N04400 plate, Nickel 400 plate, Werkstoff 2.4360 plate) is the flat-product form of the nickel-copper alloy covered by ASTM B127. Supplied hot-rolled annealed or cold-rolled annealed, 3 mm to 80 mm thickness, widths to 1500 mm, lengths to 6000 mm, with EN 10204 type 3.1 or 3.2 MTC. Used in HF acid storage, HF alkylation internals, heat exchanger tube sheets, brackish-water coolers, caustic evaporator bodies and marine bulkhead. Alloy is UNS N04400; chemistry matches B164 rod and B564 forgings. Monel® is a trademark of Special Metals Corporation.
ASTM B127 Scope and Product Types for Monel 400 Plate
ASTM B127 covers UNS N04400 as plate, sheet and strip. Thickness split: plate at 4.76 mm (3/16 in.) and thicker, sheet from 0.13 mm to under 4.76 mm, strip on slit coil. Condition is annealed only; B127 does not cover cold-worked plate. Mill route: hot-rolled annealed for plate 5 mm and thicker, cold-rolled annealed for sheet under 5 mm where flatness and finish are tighter. NDE per B127 is visual and dimensional; ultrasonic to ASTM A578 Level B on indent for tube-sheet stock.
Monel 400 Plate Size and Thickness Range
Working envelope for ASTM B127 plate ex Mumbai stock below. Thickness tolerance per B127 Table 3; flatness per Table 5; pressure-vessel orders invoke ASTM A480 Level A. Length tolerance is plus 6 mm / minus 0.
| Form | Thickness (mm) | Thickness (in.) | Width (mm) | Length (mm) | Mill route |
|---|---|---|---|---|---|
| Sheet | 0.5 to 3 | 0.020 to 0.118 | 1000 to 1500 | 2000 to 3000 | Cold-rolled annealed |
| Sheet | 3 to 5 | 0.118 to 0.197 | 1000 to 1500 | 2000 to 4000 | Cold-rolled annealed |
| Plate | 5 to 12 | 0.197 to 0.472 | 1000 to 1500 | 3000 to 6000 | Hot-rolled annealed |
| Plate | 12 to 25 | 0.472 to 1.000 | 1000 to 1500 | 3000 to 6000 | Hot-rolled annealed |
| Plate | 25 to 50 | 1.000 to 1.969 | 1000 to 1500 | 3000 to 6000 | Hot-rolled annealed |
| Plate | 50 to 80 | 1.969 to 3.150 | 1000 to 1500 | 3000 to 6000 | Hot-rolled annealed |
Plate over 80 mm is forging billet to B564 with mechanicals matched to the plate envelope. Strip below 600 mm runs slit coil.
Monel 400 Plate Chemistry per ASTM B127 (UNS N04400)
B127 chemistry matches B164 bar and B564 forgings. Detail on chemical composition.
| Element | UNS N04400 (wt %) | Role |
|---|---|---|
| Nickel (Ni) | 63.0 min | FCC matrix, sets corrosion behaviour |
| Copper (Cu) | 28.0 to 34.0 | HF and seawater passivation partner |
| Iron (Fe) | 2.5 max | Solid-solution strengthener |
| Manganese (Mn) | 2.0 max | Deoxidiser, sulphur tie-up |
| Carbon (C) | 0.3 max | Held low for weldability |
| Silicon (Si) | 0.5 max | Melt deoxidation |
| Sulphur (S) | 0.024 max | Capped for hot-working and weld soundness |
PMI on every plate at receipt; verify Ni and Cu against MTC. Free-machining Monel R-405 (N04405) at 0.025 to 0.060 percent S is bar only, never plate.
Annealed Mechanical Properties for Monel 400 Plate
ASTM B127 sets the floor at 70 ksi (480 MPa) tensile min, 28 ksi (193 MPa) yield min at 0.2 percent offset, 35 percent elongation in 2 in. Hardness 110 to 149 HBW (about 75 HRB), below the NACE MR0175 sour ceiling of 35 HRC. Detail on the mechanical properties page.
| Property | ASTM B127 Plate, Annealed | ASTM B164 Annealed Rod (cross-ref) |
|---|---|---|
| Tensile strength, min | 70 ksi (480 MPa) | 70 ksi (480 MPa) |
| Yield 0.2% offset, min | 28 ksi (193 MPa) | 25 ksi (170 MPa) |
| Elongation in 2 in., min | 35% | 35% |
| Hardness, typical | 110 to 149 HBW | B60 to B75 HRB |
| Impact toughness (Charpy V, room temperature) | typical > 200 J | typical > 200 J |
Mill heats typically clear yield by 5 to 10 ksi over the B127 floor. ASME Section VIII Div 1 duty: allowable stress per ASME BPVC Section II Part D.
Surface and Edge Conditions for Monel 400 Plate
Surface and edge condition controls downstream fabrication cost; specify on the RFQ.
| Surface | Description | Typical use |
|---|---|---|
| Hot-rolled mill (HR) | Black oxide scale from hot-rolling | Bulkhead, machined or painted pieces |
| Hot-rolled pickled (HRAP) | HNO3 / HF descaled, matte | Pressure vessel, tube-sheet, HF acid duty |
| Cold-rolled bright (2B) | Bright finish from cold-rolling pass | Instrument panels, polished tank liners |
| Ground | Ground to drawing flatness and Ra | Tube-sheet face, sealing surfaces |
| Polished | Belt-polished, Ra < 0.4 micrometre | Pharma vessels, food-grade pieces |
Edge options: mill, sheared (up to 25 mm), sawn (over 25 mm), plasma or laser (HAZ present), waterjet (no HAZ, preferred for HF acid). Default is sheared sheet, sawn plate over 25 mm.
Applications for Monel 400 Plate
The plate runs where the fluid attacks stainless and copper alloys but stays inside the nickel-copper passivation window:
- HF acid storage shells and downcomer pieces in HF alkylation per API RP 751; see HF acid resistance.
- Heat exchanger tube sheets drilled for seamless tube in brackish-water box coolers and seawater units.
- Brackish-water piping flat pieces and butt-strap repair plates offshore; see seawater corrosion.
- Naval marine bulkhead for non-magnetic compartments; permeability close to 1.0 above 51 C. See magnetic permeability.
- Caustic soda (NaOH) evaporator bodies; handles caustic to 80 percent at 150 C.
- Crude overhead condenser shells and pharma reactor liners for fluoride and mixed-acid streams.
Certification, Traceability and Inspection
Every plate is heat-numbered and stamped with heat number, plate number, spec (B127), UNS N04400, thickness and condition. EN 10204 type 3.1 ships as standard; type 3.2 (Lloyds, BV, DNV or TUV witness) on indent for nuclear, sour service and NORSOK.
| Certificate | What it covers | Typical use |
|---|---|---|
| EN 10204 type 2.2 | Non-specific test report, mill internal data | Not accepted for ASTM B127 plate; default upgrade to 3.1 |
| EN 10204 type 3.1 | Heat-specific MTC, mill metallurgist sign-off | Standard commercial, refinery, marine |
| EN 10204 type 3.2 | 3.1 plus third-party inspector counter-signature | NACE sour service, nuclear, NORSOK, customer witness |
| PMI report | Hand-held XRF or OES verification of Ni and Cu | Receipt inspection, HF acid service |
| UT report | ASTM A578 Level B ultrasonic test | Tube-sheet stock, pressure-vessel plate |
Traceability chain: heat to plate to drawing item to fabricated piece, preserved on the MTC and plate stencil. For NACE MR0175 shipments the MTC carries the compliance statement, hardness reading and heat-treat condition.
Frequently Asked Questions on Monel 400 Plate
What is Monel 400 plate? Flat-product form of nickel-copper alloy UNS N04400 to ASTM B127 in the annealed condition. Thicknesses 3 mm to 80 mm, widths to 1500 mm, lengths to 6000 mm, hot-rolled or cold-rolled, with mill, pickled or polished surface. Input stock for HF acid vessels, tube sheets and marine bulkhead.
What sizes of Monel 400 plate are available? TorqBolt stocks 3 mm to 80 mm thickness, 1000 to 1500 mm width, lengths to 6000 mm. Below 5 mm runs cold-rolled as sheet; 5 mm to 80 mm runs hot-rolled annealed. Edges sheared, sawn, plasma, laser or waterjet to drawing.
Does Monel 400 plate need NACE certification for sour service? For H2S sour service the plate clears NACE MR0175 / ISO 15156-3 at the 35 HRC nickel-copper ceiling. Annealed B127 plate at 110 to 149 HBW (about 75 HRB) sits well below the cap. Sour-service plate ships EN 10204 type 3.2 plus the NACE compliance statement on the MTC. See sour service applications.
Why is Monel 400 plate priced higher than SS 316L plate? Monel 400 carries 63 to 70 percent nickel and 28 to 34 percent copper against 10 to 14 percent nickel in 316L, so raw-material input cost runs 4 to 6 times higher per kilogram, with smaller mill heats adding conversion cost. The premium pays back in HF acid, brackish water and caustic duty. See pricing and vs stainless.
Related Pages
Standards: ASTM B127, B164, B165, B163, B564, F468, F467, NACE MR0175, DIN 17743. Properties: chemistry, mechanical, density, melting point, magnetic permeability, machinability, welding, heat treatment, corrosion, seawater, HF acid. Forms: sheet, round bar, pipe, tubing, wire, forging, flanges, fittings. Fasteners: bolts, nuts, hex bolts, stud bolts, washers. Applications: HF alkylation, sour service, marine, nickel-copper, what is Monel 400, UNS N04400, vs stainless, vs C276, vs K-500, data sheet, specifications, pricing, main reference.
Request a Quote. For Monel 400 plate to ASTM B127, UNS N04400, 3 mm to 80 mm thickness, mill / pickled / ground / polished surface, sheared / sawn / plasma / waterjet edge, EN 10204 type 3.1 or 3.2 MTC: send drawing and quantity to info@torqbolt.com or WhatsApp +91-22-66157017. Heat-numbered MTC plus Mumbai ex-stock price within one working day.
References. ASTM B127 (Plate, Sheet, Strip, N04400). ASTM B164 Table 1. ASTM B564 Table 1. ASTM A480. ASTM A578. NACE MR0175 / ISO 15156-3. EN 10204. API RP 751. ASME BPVC Section II Part D.
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