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 leaves Dilovası on timber skids in packs of up to 5 t, steel-strapped with corner protectors and the heat number stencilled on every plate. Six-metre plate loads 24–25 t into a 40' HC. 12 m and heavy plate go by flat-rack or breakbulk from Derince port. Customs code 7208.51 / 7208.52.
| 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
Documentation for P460NH steel plate: EN 10204 3.1 mill certificate as standard (heat number, analysis, tensile, Charpy, condition); 3.2 with an independent inspector, EN 10160 UT reports and additional low-temperature Charpy tests are available on plates above 8 mm at order.
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.