P280GH (EN material number 1.0426) is a carbon-manganese pressure vessel steel standardised under EN 10222-2:2000. "P" denotes pressure service grade, "280" is the minimum yield strength in MPa, and "GH" indicates elevated-temperature suitability (up to ~400 °C). Its chemical composition features C = 0.08–0.20%, Mn = 0.90–1.50%, and no alloying additions, giving tensile strength of 530–680 MPa, elongation ≥ 22%, and Charpy KV2 ≥ 34 J at +20 °C. P280GH is widely used for pressure vessel shells, heat exchanger tube sheets, boiler nozzles, forged flanges, and seamless rolled rings in European-standard projects worldwide.
P280GH Steel at a Glance
P280GH is a carbon-manganese pressure vessel steel defined under EN 10222-2:2000 — the European standard governing steel forgings for pressure equipment. Its official EN material number is 1.0426, which is how the grade appears on mill test certificates, material databases, and drawing callouts across European engineering practice.
The designation encodes a specification. P denotes a pressure-service grade; 280 represents the minimum yield strength in megapascals; and GH is a German-derived suffix (from höhere Temperaturen, meaning elevated temperatures), confirming the grade is engineered for high-temperature duty rather than ambient-only service.
P280GH sits at the entry tier of the EN 10222-2 elevated-temperature grade family. It covers continuous pressure service up to approximately 400 °C — above that threshold, more specialised creep-resistant alloys are required.
"P280GH's chemistry is actively engineered for elevated-temperature service, with carbon and manganese ranges calibrated to satisfy strength, weldability, toughness, and creep margin simultaneously — not as competing constraints, but as a single integrated design."
P280GH Chemical Composition (EN 10222-2)
The alloy design of P280GH is deliberately lean. Strength and toughness are achieved through controlled carbon and manganese rather than expensive alloying additions, which simultaneously keeps weldability high and material cost predictable.
| Element | Symbol | Min % | Max % | Metallurgical Purpose |
|---|---|---|---|---|
| Carbon | C | 0.08 | 0.20 | Primary strengthening; solid-solution hardening; carbide formation for strength retention at temperature |
| Silicon | Si | 0.10 | 0.60 | Deoxidiser during steelmaking; mild solid-solution strengthener in ferrite |
| Manganese | Mn | 0.90 | 1.50 | Improves hardenability; strengthens ferrite; neutralises sulphur as MnS to prevent hot-shortness |
| Phosphorus | P | — | 0.025 | Strictly limited — phosphorus segregation at grain boundaries impairs toughness |
| Sulphur | S | — | 0.015 | Tightly capped to prevent hot-shortness during forging and sulphide stringer formation |
| Source: EN 10222-2:2000, Table 1. Ladle analysis values. Product analysis limits may differ by tolerance increment per the standard. | ||||
Why the Carbon Range Is 0.08–0.20%
The lower bound of 0.08% ensures sufficient pearlite and solid-solution strengthening to meet the 280 MPa yield floor. The 0.20% ceiling limits the carbon equivalent (CE) to levels that keep preheat requirements low in most fabrication environments, placing P280GH firmly in the category of readily weldable pressure steels. This balance is engineered — not arbitrary.
Manganese's Dual Role
At 0.90–1.50%, manganese performs two functions simultaneously: it boosts hardenability so that uniform through-section properties can be achieved during heat treatment of thick-walled forgings; and by combining with sulphur to form MnS rather than the embrittling FeS phase, it protects against hot-shortness during the forging process itself. This tightly controlled chemistry is the foundation that makes P280GH one of the most reliably manufacturable grades for heavy-section 1.0426 P280GH forged steel parts across pressure vessel, boiler, and heat exchanger applications.
§ 03 — Mechanical PropertiesMechanical Properties per EN 10222-2
Properties are specified at room temperature after final heat treatment. Values for thicker sections (typically >100 mm) may be marginally relaxed per the standard's thickness provisions.
| Property | Condition | Requirement | Test Method |
|---|---|---|---|
| Tensile Strength Rm | Room temperature (20 °C) | 530–680 MPa | EN ISO 6892-1 |
| Yield Strength Rp0.2 | Room temperature | ≥ 280 MPa | EN ISO 6892-1 |
| Elongation A | Room temperature | ≥ 22% | EN ISO 6892-1 |
| Reduction of Area Z | Room temperature | ≥ 40% | EN ISO 6892-1 |
| Impact Energy KV2 | +20 °C | ≥ 34 J (avg of 3) | EN ISO 148-1 (Charpy V-notch) |
| Hardness (typical) | Room temperature (20 °C) | 152–207 HBW | EN ISO 6506-1 (Brinell) |
| Source: EN 10222-2:2000. Values are minimum requirements unless shown as a range. Test location per EN 10222-2 Clause 9 (quarter-thickness or mid-radius). | |||
Elevated-Temperature Yield Strength
For pressure vessel design calculations, EN 10222-2 provides elevated-temperature Rp0.2 values. As a reference guide, P280GH retains approximately the following yield strength at increasing temperatures:
| Temperature (°C) | Approx. Rp0.2 (MPa) | Design Guidance |
|---|---|---|
| 20 °C | ≥ 280 | Full rated strength; standard test and reference condition |
| 100 °C | ~250 | Minor softening; generally within standard design margins |
| 200 °C | ~215 | Must use elevated-temperature values explicitly in design calculations |
| 300 °C | ~185 | Significant reduction — verify directly against EN 10222-2 annex tables |
| 400 °C | ~160 | Approaching the practical service limit for this grade |
| Note: Indicative reference figures for preliminary design only. For certified engineering calculations always use tabulated values from EN 10222-2:2000 directly. | ||
Critical Temperature Limit — 400 °C: P280GH is not qualified under EN 10222-2 for continuous service above 400 °C. Above this threshold, creep — time-dependent plastic deformation under sustained load — begins to govern material behaviour. The 100,000-hour creep rupture strength of P280GH declines steeply above 400 °C. For higher temperatures select: 16Mo3 (to ~530 °C), 13CrMo4-5 (to ~580 °C), 10CrMo9-10 (to ~600 °C), or P91/X10CrMoVNb9-1 (to ~620 °C). Using P280GH beyond its rated temperature ceiling risks progressive creep deformation and premature failure of safety-critical pressure-bearing components.
Heat Treatment of P280GH Forgings
The standard delivery condition for P280GH under EN 10222-2 is normalised (N) or normalised and tempered (N+T). For pressure components requiring tighter impact toughness control, quenched and tempered (Q+T) condition may be specified by the buyer.
P280GH vs Similar Pressure Vessel Grades
Selecting the right grade depends on maximum operating temperature, whether creep exposure is expected, and fabrication requirements. P280GH sits at the base of the EN 10222-2 elevated-temperature ladder.
Grade selection guidance: For pressure service up to 400 °C where weldability and economy are priorities, P280GH is the most practical and widely certified choice. If operating temperature is uncertain or could be exceeded in process upset conditions, upgrading to 16Mo3 provides meaningful temperature headroom at a modest cost premium. Never extend P280GH into creep territory based on interpolated data — always consult EN 10222-2 elevated-temperature tables directly and engage a structural integrity engineer for critical applications.
Industrial Applications of P280GH Forgings
P280GH's combination of strength, toughness, weldability, and elevated-temperature performance makes it the default selection for a wide range of pressure-equipment forgings in European-standard industrial projects worldwide.
Forgeability and Manufacturing Considerations
P280GH is rated as a good-to-excellent forging steel. Its controlled carbon and sulphur ceiling (≤0.015%) minimise hot-shortness risk during the repeated heating-and-deformation cycles of open-die forging, and its manganese content assists grain refinement throughout the working range.
Hot-Working Temperature Range
The recommended forging range is 1150–850 °C. The upper limit is set by oxidation and incipient grain boundary liquation risk at very high temperatures. The 850 °C lower boundary corresponds approximately to the Ar3 transformation, below which austenite begins decomposing to ferrite-pearlite — working below this temperature introduces structural banding and compromises toughness.
Section Size and Through-Hardening
For large-section forgings (rings with wall thickness greater than 150 mm, or discs larger than 400 mm in diameter), through-section property uniformity must be confirmed by mechanical testing at the representative quarter-thickness location as required by EN 10222-2. For very heavy sections where normalising alone is insufficient, quench-and-temper condition should be specified.
Weldability and Carbon Equivalent
Carbon equivalent (CE) for P280GH, calculated per IIW formula (CE = C + Mn/6 + (Cr+Mo+V)/5 + (Ni+Cu)/15), typically falls in the 0.38–0.42% range at standard analysis — comfortably below the 0.45% threshold above which preheat is mandated for most section thicknesses. This confirms P280GH as a weld-friendly pressure steel for standard fabrication and repair environments. Engineers specifying material for their next project can review the full size range and shape capabilities for P280GH open die forgings and seamless rolled rings available from Jiangsu Liangyi.
§ 08 — Quality AssuranceQuality Assurance and Inspection Requirements
P280GH forgings supplied to EN 10222-2 must be accompanied by a 3.1 Mill Test Certificate (MTC) per EN 10204, recording the actual heat analysis, mechanical test results, heat treatment parameters, and dimensional compliance. For pressure equipment requiring third-party inspection, an independent inspection body designated by the project or buyer may be engaged.
Non-Destructive Testing (NDT)
- Ultrasonic Testing (UT) — Volumetric inspection per EN 10228-3 to detect internal discontinuities, segregation, and porosity. Standard requirement for pressure-rated forgings.
- Magnetic Particle Inspection (MT) — Surface and near-surface crack detection per EN ISO 17638, applied after final machining to identify forging seams or heat treatment cracks.
- Dimensional Inspection — Full verification of OD, ID, thickness, flatness, and concentricity tolerances against the engineering drawing.
- Hardness Survey — Multiple measurement points on the forging surface to confirm heat treatment uniformity across the section.
Procurement and Sourcing Guidance
Selecting a P280GH forging supplier requires evaluation beyond price. These factors directly determine whether forgings will perform reliably in service and pass third-party inspection on first submission.
Custom P280GH Forged Parts from Jiangsu Liangyi
Established in 1997 and ISO 9001:2015 certified, Jiangsu Liangyi Co., Limited manufactures custom P280GH forged steel parts for industrial customers in over 50 countries. Our production range covers components from 30 kg to 30,000 kg per piece, with an annual manufacturing capacity of 120,000 tonnes.
Every P280GH forging is manufactured within our own 80,000 m² integrated facility in Jiangyin City, Jiangsu Province — from steel melting (30t EAF + LF + VD/VOD) through open-die forging, heat treatment, CNC machining, and full NDT inspection under a single ISO 9001:2015 quality management system. No subcontracting. Full traceability from liquid steel to finished certified part.
Standard P280GH Product Range
The following shapes are available as custom P280GH pressure vessel forgings, manufactured to order from certified EN 1.0426 steel with full EN 10204 documentation:
- Forged round bars, step shafts, and gear shafts — Diameter 50–1500 mm; length up to 12 m
- Seamless rolled rings and forged flanges — Outer diameter up to 5000 mm; custom cross-sections available
- Forged hubs, housings, sleeves, and heavy-wall hollow bars — Wall thickness up to 350 mm; hollow ID from 100 mm
- Forged discs, blocks, and flat plates — Custom dimensions per engineering drawing
- Forged tube sheets — For heat exchangers, pressure vessels, and boiler applications
- Custom engineered forgings — Produced from client drawings and technical specifications
Request a Custom P280GH Forging Quote
Send us your drawing or technical specification. We provide factory-direct quotations with full EN 10222-2 material traceability and ISO 9001:2015 quality documentation. EN 10204 Type 3.1 MTC available on request.
View P280GH Product Page & Get a Quote →P280GH Steel — Frequently Asked Questions
The following questions represent the most common queries from engineers and procurement teams evaluating P280GH (EN 1.0426) for pressure equipment applications. Each answer is written to be directly usable in material specification reviews and RFQ documentation.
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