What is 16Mo3 steel plate?
16Mo3 is a low-alloy heat-resisting steel: 0.12–0.20 % carbon, 0.40–0.90 % manganese and — the defining addition — 0.25–0.35 % molybdenum, which forms fine carbides that resist softening and creep at temperature. EN 10028-2 certifies its 0.2 % proof strength from 50 °C to 500 °C (243 MPa at 100 °C, 213 at 200 °C, 194 at 300 °C, 174 at 400 °C, 137 at 500 °C, plate ≤ 16 mm) and gives creep-rupture values for 10 000 to 200 000 h between 450 and 530 °C — data no carbon grade offers. Room-temperature yield is 275 MPa and tensile 440–590 MPa; impact 31 J at +20 °C (40 J long.). It is delivered normalised (or normalised + tempered) and is the standard material for superheater headers and drums, economiser and evaporator plates, flue-gas heat-recovery boilers, hot-gas ducts and refinery vessels in the 400–500 °C range. Its DIN name 15Mo3 is still common in Germany and Turkey; ASTM A204 Grade B is the accepted equivalent.
Chemical composition
| Element | C | Si | Mn | P | S | Mo | Cr | Cu | Ni | N |
|---|---|---|---|---|---|---|---|---|---|---|
| max. % (ladle) | 0.12–0.20 | ≤ 0.35 | 0.40–0.90 | ≤ 0.025 | ≤ 0.010 | 0.25–0.35 | ≤ 0.30 | ≤ 0.30 | ≤ 0.30 | ≤ 0.012 |
Al ≤ 0.040 (no deliberate Al-killing), Nb ≤ 0.020, Ti ≤ 0.03, V ≤ 0.02. CEV ≈ 0.45–0.50.
Mechanical properties
| Thickness | Yield ReH min (MPa) | Tensile Rm (MPa) | Elongation A min | Impact KV |
|---|---|---|---|---|
| ≤ 16 mm | 275 | 440–590 | 22 % | 31 J at +20 °C (40 J long.) |
| > 16–40 mm | 270 | 440–590 | 22 % | 31 J at +20 °C |
| > 40–60 mm | 260 | 440–590 | 22 % | 31 J at +20 °C |
| > 60–100 mm | 240 | 430–580 | 21 % | 31 J at +20 °C |
| Rp0.2 at 100 / 200 / 300 / 400 / 500 °C (≤ 16 mm) | 243 / 213 / 194 / 174 / 137 | — | — | — |
Equivalent grades
| System | Grade | Note |
|---|---|---|
| DIN 17155 | 15Mo3 | direct predecessor |
| ASTM | A204 Gr. B | C-½Mo plate, 275 MPa |
| ASTM | A209 T1 / A335 P1 | tube / pipe analogues |
| JIS G4109 | SB450M | |
| GB 713 | 15MoG (near) | |
| BS 1501 | 240 | historic |
Thickness range and stock sizes
| Thickness | Widths × lengths | Availability |
|---|---|---|
| 6–12 mm | 2 000 × 6 000 | to order 4–6 weeks |
| 15–40 mm | 2 000 / 2 500 × 6 000–12 000 | to order 4–8 weeks |
| 50–100 mm | 2 000–2 500 × 6 000 | to order 6–8 weeks, UT |
Weight per m² and per plate
| Thickness | kg/m² | 1 500 × 6 000 (kg) | 2 000 × 6 000 (kg) | 2 500 × 12 000 (kg) |
|---|---|---|---|---|
| 6 mm | 47.1 | 424 | 565 | 1 413 |
| 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 |
| 100 mm | 785.0 | 7 065 | 9 420 | 23 550 |
Figures are nominal: thickness tolerance to EN 10029 class A can add 4 % on the thinnest plate. We invoice theoretical weight by default and actual weight on request.
Welding, cutting and forming
Molybdenum changes the rules: use matching Mo-alloyed consumables (E Mo B basic rods, G MoSi wire, EN ISO 3580 / 21952), preheat 150–200 °C at every thickness above 10 mm, interpass 200–300 °C, and post-weld heat treatment at 580–620 °C (holding 2 min/mm, min 30 min) which most codes make mandatory for 16Mo3 regardless of thickness. Hydrogen control is critical (dry basic consumables, slow cooling under insulation). Cold forming to 3 × t; hot forming at 950–1 050 °C followed by normalising at 900–940 °C. Hardness after welding is checked (≤ 250 HB after PWHT).
Where it is used
- Superheater headers, steam drums and boiler shells above 400 °C
- Economisers, evaporators and heat-recovery steam generators
- Waste-to-energy and biomass boiler membrane walls
- Flue-gas ducts, hot-gas heat exchangers
- Refinery and petrochemical vessels (hydrogen service with care)
- Power-plant piping components cut from plate
16Mo3 vs P265GH / P355GH
The carbon GH grades are certified to 400 °C; 16Mo3 goes to 500 °C and carries creep-rupture data. At room temperature its strength (275 MPa) sits between P265GH and P355GH, so it is never chosen for strength — only for temperature. It costs roughly 2.5 times the carbon boiler plate and demands Mo consumables, high preheat and PWHT. Below 400 °C stay with P265GH or P355GH; above 500 °C the next step is 13CrMo4-5 (on request).
Price
16Mo3 carries the highest premium in our boiler list — about 500 USD/t over the S235JR base — driven by molybdenum and EU sourcing; the band below is indicative FOB Istanbul for mill-order plate. Small lots from EU stock are quoted separately.
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
Export packing of 16Mo3 steel plate: skids up to 5 t or loose on bearers, strapped, heat numbers stencilled. Loading: ≤ 6 m: 40' HC 24–25 t; longer flat-rack. Tariff heading follows the surface: 7208 hot-rolled, 7209 cold-rolled, 7210 coated, 7225 / 7226 alloy.
| Term | Detail |
|---|---|
| MOQ | 10 t (mill lot; smaller from EU stock at premium) |
| Incoterms | FOB Istanbul · CIF / CFR Gulf, Africa · DAP EU, Balkans, Iraq, Caucasus · DAP Aktau |
| Lead time | Imported to order 4–8 weeks |
| Packing | Skids up to 5 t or loose on bearers, strapped, heat numbers stencilled |
| Container / truck | ≤ 6 m: 40' HC 24–25 t; longer flat-rack |
| 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 16Mo3 steel plate starts with the EN 10204 3.1 mill certificate: heat number, analysis, tensile, Charpy and the condition of supply. Where the client's QA requires it we book 3.2 inspection before rolling rather than after. EN 10160 ultrasonic reports and supplementary impact tests at your design temperature are available on plate above 8 mm.
How to order
State thickness × width × length, tonnage, design temperature and pressure, code, certificate 3.1 / 3.2 with inspector, UT class and delivery condition (+N or +NT); we confirm the mill slot and price within one working day.
Standards
- EN 10028-2:2017 — 16Mo3, 1.5415
- DIN 17155 — 15Mo3 (withdrawn)
- PED 2014/68/EU; AD 2000 W1
- EN 10160 UT; EN 10164 Z on request
Grades
Grade data sheets (chemistry, mechanicals, equivalents) are on our reference site: 16Mo3 · P265GH · P355GH
Frequently asked questions
What is 16Mo3 steel?
A low-alloy, molybdenum-bearing (0.25–0.35 % Mo) pressure-vessel and boiler steel to EN 10028-2 (1.5415, ex DIN 15Mo3) with certified strength and creep data up to 500 °C; room-temperature yield 275 MPa.
What is the ASTM equivalent of 16Mo3?
ASTM A204 Grade B (carbon-½ molybdenum plate) for plate; A209 T1 tube and A335 P1 pipe are the corresponding tubular grades.
What is the maximum temperature for 16Mo3?
About 500 °C for continuous service with creep design (EN 10028-2 tabulates creep-rupture strength to 530 °C); above that chromium-molybdenum grades such as 13CrMo4-5 are used.
Does 16Mo3 need preheating and PWHT?
Yes — preheat 150–200 °C, Mo-alloyed consumables and post-weld heat treatment at 580–620 °C are standard code requirements for 16Mo3 at practically every thickness.
Is 16Mo3 the same as 15Mo3?
Yes — 15Mo3 is the DIN 17155 name; 16Mo3 (1.5415) is the EN 10028-2 successor with essentially the same chemistry.