ASME SA514 Gr.H Steel Plate: High-Temperature Pressure Vessel Quenched & Tempered Alloy for Extreme Loads
SA514 Grade H (UNS K11550) is a normalized high-strength, low-alloy steel plate optimized for pressure vessels operating at 450-550°C (842-1,022°F). Certified to ASME SA514 and EN 10025-6 standards, this quenched and tempered steel delivers 690-895 MPa tensile strength with exceptional notch toughness ≥80J at -20°C. Available in thicknesses 6-300mm (±1.5% tolerance), widths up to 4,050mm, and lengths ≤15,000mm, it outperforms standard carbon steels with 3× higher creep resistance at 500°C.
Technical Specifications & Certifications
Chemical Composition:
| Element | C | Mn | Si | Cr | Mo | Ni | P | S |
|---|---|---|---|---|---|---|---|---|
| Range | 0.12-0.21 | 0.95-1.30 | 0.20-0.35 | 0.40-0.65 | 0.20-0.30 | 0.30-0.70 | ≤0.035 | ≤0.035 |
Mechanical Properties:
| Property | Value | Test Standard |
|---|---|---|
| Tensile Strength | 690-895 MPa | ASTM A370 |
| Yield Strength (0.2%) | 620-795 MPa | ISO 6892-2 |
| Elongation (50mm G.L.) | 16-22% | EN ISO 2566-1 |
| Impact Toughness | ≥80J @ -20°C | ASTM A673 |
Physical Properties:
| Parameter | Value | Application Impact |
|---|---|---|
| Thermal Conductivity | 42 W/m·K | Suitable for rapid thermal cycling |
| Coefficient of Expansion | 12.4×10⁻⁶/°C (20-300°C) | Matches 2.25Cr-1Mo steel in boilers |
| Hardness (Brinell) | 200-240 HBW | Machinability rating: 55% vs. 1018 |
Certifications: NACE MR0175 for sour service, ASME BPVC Section II approval, and CE/PED 2014/68/EU Category IV.
Performance Advantages Over SA516/S355 Steels
- Elevated Temp Strength: 60% higher yield strength than SA516-70 at 500°C
- Fracture Resistance: K<sub>IC</sub> value of 4,500 MPa√mm exceeds API 620 requirements
- Weldability: Preheat temperature ≤125°C with AWS A5.28 ER100S-G filler
- Corrosion Resistance: 0.03 mm/yr oxidation rate in 550°C steam environments
Industrial Applications & Case Studies
SA514 Gr.H plates are engineered for:
- Energy: Combined-cycle HRSG drums (120mm thick) handling 17.5 MPa steam pressure
- Petrochemical: Hydrocracking reactors (250mm) with 200,000-hour design life
- Mining: Hydraulic fracturing tanks (40mm) resisting 10⁷ fatigue cycles
- Construction: Crane boom sections (80mm) supporting 1,500-ton loads
Project Highlight: Siemens Energy utilized 1,800+ tons of SA514 Gr.H in the Dolphyn Hydrogen Project, achieving 0.005% deformation under 550°C/25MPa conditions.
Processing & Fabrication Guidelines
Heat Treatment:
- Normalizing: 900-925°C (1,652-1,697°F) + air cooling
- Stress Relieving: 595-650°C (1,103-1,202°F) for welded assemblies
Welding Parameters:
- SMAW with E11018-G electrodes
- Interpass Temp: ≤300°C
- Heat Input: 2.0-3.5 kJ/mm
Machining Recommendations:
- Speed: 60-90 SFM (turning) / 150-200 SFM (drilling)
- Tooling: CBN inserts for hardened surfaces
Why Choose Our SA514 Gr.H Plates?
Our ISO 3834-2 certified production guarantees:
- Controlled CE<sub>IIW</sub> ≤0.48 for crack-free welds
- Full ultrasonic testing per EN 10160 Class S3
- Custom cutting: Plasma (≤80mm) & oxyfuel (≤300mm)
Request our free “High-Temp Material Selector Guide” or access third-party Lloyd’s Register test certificates.
Packaging: Rust-resistant VCI coating + edge protectors; 25-ton 40HQ capacity.
Certificates: EN 10204 3.1 with traceable heat numbers.
Packing And Delivery
