What is P460NH steel plate?
P460NH (1.8935) reaches its 460 MPa by the same route as P355NH — aluminium-killed, niobium-vanadium-titanium micro-alloyed, normalised — but with a richer balance: manganese up to 1.70 %, nickel up to 0.80 %, vanadium up to 0.20 % and a nitrogen allowance that lets vanadium nitride refine and strengthen the ferrite. The NH suffix means the certificate carries yield values at elevated temperature (typically 415 MPa at 100 °C, 345 MPa at 300 °C, 290 MPa at 400 °C), so the designer can use the higher allowable stress in the pressure code up to 400 °C, and the −20 °C Charpy of 40 J longitudinal is guaranteed. Against P355NH the allowable stress is about 30 % higher, which for a given diameter and pressure gives a 25–30 % thinner shell: an 8 m³ air receiver at 40 bar goes from 22 mm to 16 mm, a 60 mm reactor shell to 45 mm — fewer weld passes, lighter lifts, and often the escape from mandatory PWHT thickness thresholds. Typical applications are high-pressure air and gas receivers, hydraulic and nitrogen accumulators, CNG and hydrogen buffer vessels, heavy-wall columns and reactors, boiler drums where the design is thickness-limited, and mobile pressure equipment (road tankers, ISO tanks) where every tonne of tare counts. The plate is also used structurally in cranes and mobile equipment when a certified normalised 460 MPa plate is wanted; the structural sibling is S460N.
Chemical composition
| Element | C | Si | Mn | P | S | Al | Nb | V | Ti | Ni | Cr | Mo | Cu | N |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| max. % (ladle) | ≤ 0.20 | ≤ 0.60 | 1.10–1.70 | ≤ 0.025 | ≤ 0.015 | ≥ 0.020 | ≤ 0.05 | ≤ 0.20 | ≤ 0.03 | ≤ 0.80 | ≤ 0.30 | ≤ 0.10 | ≤ 0.70 | ≤ 0.025 |
Nb + Ti + V ≤ 0.22 %. CEV typically 0.48–0.53 — preheat is required for most thicknesses.
Mechanical properties
| Thickness | Yield ReH min (MPa) | Tensile Rm (MPa) | Elongation A min | Impact KV |
|---|---|---|---|---|
| ≤ 16 mm | 460 | 570–720 | 17 % | 40 J at −20 °C (long.) / 27 J trans. |
| > 16–40 mm | 445 | 570–720 | 17 % | 40 J at −20 °C |
| > 40–60 mm | 430 | 570–720 | 17 % | 40 J at −20 °C |
| > 60–80 mm | 415 | 550–700 | 17 % | 40 J at −20 °C |
| Rp0.2 at 200 / 300 / 400 °C | ≥ 370 / 345 / 290 | — | — | certified (NH) |
Equivalent grades
| System | Grade | Note |
|---|---|---|
| DIN 17102 | WStE 460 | direct predecessor |
| EN 10028-3 | P460N / P460NL1 / P460NL2 | siblings: without ET values / −40 / −50 °C |
| EN 10025-3 | S460N / S460NL | structural equivalents, no pressure certification |
| ASTM | A737 Gr. C | Nb-V normalised pressure plate, 415 MPa |
| ASTM | A612 (approx.) | high-strength normalised C-Mn-Si |
| EN 10028-6 | P460Q / P460QH | quenched-and-tempered route to the same strength |
Wall-thickness saving against P355
| Vessel | Design pressure | Inside Ø | P355NH wall | P460NH wall | Steel saved |
|---|---|---|---|---|---|
| Air receiver 8 m³ | 40 bar | 1 800 mm | 22 mm | 17 mm | ≈ 23 % |
| Nitrogen accumulator | 100 bar | 1 000 mm | 30 mm | 24 mm | ≈ 20 % |
| Process column | 25 bar at 300 °C | 2 800 mm | 28 mm | 21 mm | ≈ 25 % |
| Reactor shell | 60 bar at 350 °C | 3 000 mm | 68 mm | 52 mm | ≈ 24 % |
| CNG buffer | 250 bar | 600 mm | 45 mm | 35 mm | ≈ 22 % |
Illustrative only — the vessel designer's calculation to the applicable code governs; savings shrink where thickness is set by external pressure, nozzles or fatigue.
Thickness range and stock sizes
| Thickness | Widths × lengths | Availability |
|---|---|---|
| 8–15 mm | 2 000 / 2 500 × 6 000–12 000 | to order 5–7 weeks |
| 20–40 mm | 2 500 / 3 000 × 6 000–12 000 | to order 5–7 weeks |
| 50–80 mm | 2 500 × 6 000–10 000 | to order 7–8 weeks; UT S1/E1 |
| Head blanks | circles to Ø 3 500 mm | plasma-cut, bevelled |
Weight per m² and per plate
| Thickness | kg/m² | 1 500 × 6 000 (kg) | 2 000 × 6 000 (kg) | 2 500 × 12 000 (kg) |
|---|---|---|---|---|
| 8 mm | 62.8 | 565 | 754 | 1 884 |
| 10 mm | 78.5 | 707 | 942 | 2 355 |
| 12 mm | 94.2 | 848 | 1 130 | 2 826 |
| 15 mm | 117.8 | 1 060 | 1 413 | 3 533 |
| 20 mm | 157.0 | 1 413 | 1 884 | 4 710 |
| 25 mm | 196.3 | 1 766 | 2 355 | 5 888 |
| 30 mm | 235.5 | 2 120 | 2 826 | 7 065 |
| 40 mm | 314.0 | 2 826 | 3 768 | 9 420 |
| 50 mm | 392.5 | 3 533 | 4 710 | 11 775 |
| 60 mm | 471.0 | 4 239 | 5 652 | 14 130 |
| 80 mm | 628.0 | 5 652 | 7 536 | 18 840 |
Nominal weights — mill tolerance to EN 10029 class A adds up to +4 % on thin plate; invoiced on theoretical weight unless agreed otherwise.
Welding, cutting and forming
P460NH welds well with qualified procedures but demands discipline: basic low-hydrogen consumables of the 500 MPa class (E50 4 / G50 4 or Ni-Mo wires for thick sections), preheat 100 °C from 15 mm and 125–150 °C above 30 mm, interpass ≤ 220 °C, heat input 1.0–2.5 kJ/mm to keep the fine grain and the −20 °C toughness in the HAZ. PWHT at 550–580 °C where the code requires it; the mill can supply simulated-PWHT test data. Cold forming to R ≥ 5 t; hot forming needs re-normalising at 900–940 °C.
Where it is used
- High-pressure air, nitrogen and gas receivers
- Hydraulic accumulators and CNG / hydrogen buffer vessels
- Heavy-wall columns, reactors and hydro-cracker shells
- Boiler drums and headers where thickness is limiting
- Road tankers, ISO tanks and mobile pressure equipment
- Crane and mining structures needing certified normalised 460 MPa plate
P460NH vs P355NH vs S460N
P355NH is the everyday fine-grain pressure plate — cheaper per ton, easier to weld, no preheat below 25 mm; P460NH pays for itself when the vessel is thickness-driven or weight-critical, where the 25–30 % thinner wall outweighs the higher price per ton and the preheat. S460N is the same steel without pressure-code certification and elevated-temperature values, for structural use. For −40 °C service the family continues as P460NL1; for still higher strength the Q&T route is P460Q / P500Q.
Price
P460NH is priced about 380 USD/t over the S235JR base as an imported high-strength fine-grain pressure plate — roughly 130 USD/t above P355NH, which the thinner wall usually more than repays; UT, Z-quality and 3.2 inspection are added per ton. Indicative FOB Istanbul band below; firm price per plate list within a working day.
Bands from our weekly export list (September 2026), FOB Istanbul, full-container quantities, excluding freight and certificates. Firm price per project on RFQ within one working day.
Export and packing
P460NH steel plate is packed as follows: loose on bearers or skids ≤ 5 t, strapped, heat numbers stencilled. Loading: ≤ 6 m: 40' HC 24–25 t; 8–12 m flat-rack / breakbulk. Customs classification is by surface and alloy content — 7208, 7209, 7210, 7225 or 7226.
| Term | Detail |
|---|---|
| MOQ | 20 t (mill lot) |
| Incoterms | FOB Istanbul · CIF / CFR Gulf, Africa · DAP EU, Balkans, Iraq, Caucasus · DAP Aktau |
| Lead time | To order 5–8 weeks (EU mill programme) |
| Packing | Loose on bearers or skids ≤ 5 t, strapped, heat numbers stencilled |
| Container / truck | ≤ 6 m: 40' HC 24–25 t; 8–12 m flat-rack / breakbulk |
| Documents | Invoice, packing list, EN 10204 3.1 (3.2 on request), certificate of origin; SASO / SONCAP / PVoC on request |
| Payment | 30% advance, balance against B/L copy; L/C at sight for orders above 100 t |
Certificates and testing
Every lot of P460NH steel plate carries an EN 10204 3.1 inspection certificate listing heat, chemistry, mechanical and impact results. Third-party 3.2 certification by Lloyd's, BV, TÜV or SGS is ordered per lot. Ultrasonic examination to EN 10160 and additional low-temperature impact tests are quoted together with the plate.
How to order
Send thickness × width × length or the shell / head drawings, tonnage, design pressure and temperature, pressure code, certificate level (3.1 / 3.2), UT class, Z-quality and PWHT requirement; we return the mill programme date and price within a working day.
Standards
- EN 10028-3:2017 — P460NH, 1.8935 (also P460N, P460NL1, P460NL2)
- PED 2014/68/EU; AD 2000 W1
- EN 10160 UT; EN 10164 Z15/Z25/Z35
- DIN 17102 — WStE 460 (withdrawn)
Grades
Grade data sheets (chemistry, mechanicals, equivalents) are on our reference site: P460NH · P355NH · S460N
Frequently asked questions
What is P460NH steel?
The highest-strength normalised fine-grain pressure-vessel steel in EN 10028-3 (1.8935): 460 MPa yield, 570–720 MPa tensile, 40 J at −20 °C, with certified yield values up to 400 °C — used to make high-pressure vessels thinner and lighter.
How much thinner can a vessel be in P460NH than in P355NH?
About 25–30 % for a shell whose thickness is set by internal pressure, because the allowable stress is roughly 30 % higher; the designer's code calculation governs.
Does P460NH need preheat?
Yes — 100 °C from about 15 mm and 125–150 °C above 30 mm with low-hydrogen 500 MPa-class consumables; carbon equivalent is around 0.50.
What is the ASTM equivalent of P460NH?
No exact match; A737 Grade C (Nb-V normalised, 415 MPa) is the closest normalised pressure plate, and A612 is sometimes compared. Under ASME the code case and material approval must be checked.
Is P460NH available from stock?
No — it is a mill-order plate from EU mills, 5–8 weeks, minimum 20 t per lot, in 8–80 mm.