EN10028-2 P355GH High-Strength Pressure Vessel Steel Plate

What is EN10028-2 P355GH Steel Plates?

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Among the non-alloy quality steel grades specified under EN 10028-2, P355GH (Material No. 1.0473) is the highest strength carbon steel in the series. Its grade designation reflects its key characteristics: "P" stands for pressure vessel service; "355" represents the nominal minimum yield strength of 355 MPa at room temperature for plate thicknesses ≤ 16mm; and "GH" indicates guaranteed elevated-temperature properties.

P355GH is a fully killed, fine-grained steel produced via aluminum deoxidation practice, typically supplied in the normalized (+N) delivery condition. It supersedes the withdrawn German grade DIN 17155 H I and British grade BS 1501-161-360A. As a harmonized European standard grade under the EU Pressure Equipment Directive (PED 2014/68/EU), P355GH facilitates CE marking and regulatory compliance for pressure equipment across European and international markets.

 

 

Heat Treatment: Standard heat treatment practices for P355GH steel plate include normalizing and tempering. Normalizing eliminates residual stresses induced during hot rolling, refines the grain matrix, and improves both mechanical properties and corrosion resistance. Subsequent tempering can be performed after normalizing to further adjust hardness and notch toughness.

Delivery Conditions: P355GH steel plate is primarily supplied in As-Rolled (AR), Thermomechanically Controlled Processed (TMCP), or Normalized (+N) conditions, selected based on customer requirements and manufacturing specifications.

 

 

Steelmaking & Rolling Practice

• Primary Metallurgy: Produced via Electric Arc Furnace (EAF) + Ladle Furnace (LF) refining + Vacuum Degassing (VD) to guarantee ultra-clean steel chemistry (total oxygen content ≤ 20ppm).
• Continuous Casting: Dynamic soft reduction (DSR) technology minimizes centerline segregation, casting slabs with thicknesses of 200–300 mm.
• Controlled Rolling: Thermomechanical control processing (TMCP) combined with post-rolling normalizing at 880–940°C (1616–1724°F) with air cooling achieves a fine grain size meeting ASTM No. 8 or finer.

Fabrication Characteristics

• Weldability: Low carbon equivalent (CE} ≤ 0.42%) enables preheat-free welding for plate thicknesses ≤ 50mm. Low-alloy high-strength consumables such as AWS E7015-B2 electrodes or EN ISO 14341-A G4Si1 wire are recommended, with heat input restricted to ≤ 25kJ/cm.
• Cold Forming: Demonstrates exceptional ductility, capable of withstanding a 180° cold bend (d = 3a), making it ideal for fabricating spun/dished heads up to 4000 mm in diameter.
• Machinability: Normalized plate hardness ranges from 140 to 190 HBW. Efficiently machined using ISO Grade K (YG-type) carbide tooling at cutting speeds of 60–80 m/min.

 

 

Element	P355GH (%)	Element	P355GH (%)
C	0.10 – 0.22	Cr	≤ 0.30
Si	≤ 0.60	Cu	≤ 0.30
Mn	1.10 – 1.70	Mo	≤ 0.08
P	≤ 0.025	Ni	≤ 0.30
S	≤ 0.015	Nb	≤ 0.020
Al	≥ 0.020	V / Ti	≤ 0.02 / ≤ 0.03
N	≤ 0.012	CEV max	0.45

 

 

Thickness (mm)	Yield ReH (MPa, min)	Tensile Rm (MPa)	Elongation A (%)
≤ 16	355	510 – 650	≥ 20
16 – 40	345	510 – 650	≥ 20
40 – 60	335	510 – 650	≥ 20
60 – 100	315	490 – 630	≥ 20
100 – 150	295	480 – 630	≥ 20
150 – 250	280	470 – 630	≥ 20

 

 

Parameter	Specification
Thickness	5 – 300 mm (mechanical properties to 250 mm)
Width	1,500 – 4,050 mm
Length	3,000 – 18,000 mm
Delivery condition	+N (Normalized, 890–950°C) - standard
Optional condition	+AR (As-rolled, by agreement)
Thickness tolerance	EN 10029 Class B (default)
Surface quality	EN 10163-2 Class B (default)
Certification	EN 10204 3.1 / 3.2 MTC

 

 

P355GH is specified for pressure-retaining components operating from ambient temperatures up to 400°C (752°F). Core applications include fossil-fired power boiler drums, headers, downcomers, and economizers; petrochemical reactors, fractionating columns, shell-and-tube heat exchangers, and steam generators; LPG and natural gas medium-to-high pressure storage drums; and nuclear power Class 2 and Class 3 safety containment shells. It is a mandatory material option for export equipment built in compliance with the EU Pressure Equipment Directive (PED).

 

Why Choose GNEE Steel?

GNEE Steel has extensive experience supplying P355GH high-strength pressure vessel plates to EPC contractors and fabricators worldwide. We understand that high-strength steel projects demand rigorous documentation - from material traceability to welding procedure support.

Our capabilities include cutting to custom dimensions, beveling, ultrasonic testing (EN 10160), HIC testing (NACE TM0284), Z-direction testing (EN 10164), and third-party inspection by SGS, BV, DNV, or TÜV. We can provide welding procedure qualification (WPS/PQR) reference data upon request. All material is delivered with EN 10204 3.1 or 3.2 MTC.

 

FAQ

Q: How much stronger is P355GH compared to P265GH?

A: P355GH offers a minimum yield strength of 355 MPa for plates ≤ 16 mm, approximately 34% higher than P265GH's 265 MPa. This can translate to 15–25% wall thickness reduction in pressure vessel design, depending on the specific design conditions.

 

Q: What is the maximum CEV for P355GH?

A: The maximum carbon equivalent value is 0.45 per EN 10028-2 (heat analysis). Typical production values range from 0.40 to 0.43, indicating good weldability with conventional processes.

 

Q: Can P355GH be used above 400°C?

A: EN 10028-2 specifies elevated-temperature properties for P355GH up to 400°C. For continuous service above 400°C, Cr-Mo alloy steel such as 16Mo3 is recommended for adequate creep resistance.

 

Q: Does P355GH require preheating before welding?

A: For thicknesses up to 16 mm at ambient temperatures above 5°C, preheating is generally not required. For thicker plates, preheating at 100–150°C is recommended to prevent hydrogen-induced cracking.

 

 

 

 

 

 

We have excellent after-sales service. If you have any questions about EN10028-2 P355GH Pressure Vessel Steel Plates, you can contact us and we will reply to you within two hours.