P265GH is a non-alloy quality steel designed for use in pressure vessels, boilers, and heat exchangers. It is specified under the European standard EN 10028-2.
Key Specifications
Material Number: 1.0425.
Designation Meaning:
P: Pressure purposes.
265: Minimum yield strength of 265 MPa (for thicknesses ≤ 16 mm).
GH: Suitable for elevated service temperatures.
Temperature Range: Suitable for continuous operation up to approx. 400°C (752°F), and up to 450°C wall temperature for piping.
Chemical Compositions
| Element | Content (%) |
|---|
| Iron, Fe | ~98 |
| Carbon, C | 0.16-0.20 |
| Manganese, Mn | 0.70-1.40 |
| Silicon, Si | ≤ 0.40 |
| Phosphorus, P | ≤ 0.025 |
| Sulfur, S | ≤ 0.015 |
Physical Properties
| Physical Property | Metric | Imperial |
|---|
| Density | 7.85 g/cm³ | 0.284 lb/in³ |
| Melting Point | 1420-1460 °C | 2588-2660 °F |
| Boiling Point | Not available | Not available |
| Thermal Conductivity | 51 W/m·K | 354 BTU·in/(hr·ft²·°F) |
| Electrical Conductivity | ~10.7 MS/m | ~10.7 MS/m |
| Specific Heat Capacity | 480 J/kg·K | 0.114 Btu/lb·°F |
| Thermal Expansion Coefficient | 12.5 × 10⁻⁶ /K | 6.94 × 10⁻⁶ /°F |
| Electrical Resistivity | ~0.093 Ω·mm²/m | ~0.093 Ω·mm²/m |
Mechanical Properties
| Mechanical Property | Metric | Imperial |
|---|
| Tensile Strength | 410-530 MPa | 59.5-76.9 ksi |
| Yield Strength | 265 MPa | 38.4 ksi |
| Brinell Hardness | ~130 HB | ~130 HB |
| Rockwell Hardness | ~73 HRB | ~73 HRB |
| Vickers Hardness | ~131 HV | ~131 HV |
| Elongation | 23-25% | 23-25% |
| Elastic Modulus | 210 GPa | 30,500 ksi |
| Impact Energy | 27 J at 20°C | 19.9 ft·lbf at 68°F |
P265GH Processing
Welding: Suitable for common welding methods like arc welding, gas shielded welding and submerged arc welding. Preheat to 80-150°C to prevent cold cracks; post-weld heat treatment (600-650°C) is recommended for thick workpieces to reduce residual stress. Welding consumables should match its mechanical properties, complying with EN standards.
Forming: Can be hot-formed and cold-formed. Hot forming temperature ranges 900-1100°C, with slow cooling after forming to maintain toughness. Cold forming (e.g., bending, stamping) is feasible at room temperature, but avoid excessive deformation; stress relief annealing may be needed afterward.
Machining: Features good machinability. Use high-speed steel or cemented carbide tools. Adopt moderate cutting speed and feed rate; ensure sufficient cooling with cutting fluid to prevent overheating and material hardening, which may affect machining accuracy and tool life.
Heat Treatment: Delivery status is usually normalized (890-950°C, air cooling) or normalized+tempered. Post-processing heat treatment should avoid overheating, and strictly control temperature and holding time to ensure stable material performance without reducing pressure-bearing capacity.
Main Applications
Boiler and Steam System Components: As a core material for boilers and pressure vessels, P265GH is widely used in manufacturing boiler drums, superheater shells, and reheater tubes in thermal and nuclear power plants. It can withstand high-temperature steam erosion and pressure, ensuring stable operation of power generation equipment <superscript>1<superscript>4.
Petrochemical Equipment: It is applied to fabricate hydrogenation reactors, synthesis towers, and high-temperature cracking devices. It also suits oil and gas transmission pipelines (especially those with anti-H₂S corrosion design) and chemical distillation towers, adapting to harsh working environments with high temperature and pressure <superscript>4<superscript>7.
Heat Exchangers and Pressure Vessels: Used for making heat exchanger tube plates, separators, spherical tanks, and LNG storage tank liners. Its good toughness and pressure-bearing capacity meet the requirements of medium and low-temperature pressure vessel manufacturing <superscript>3<superscript>4.
Other Industrial Fields: It is employed in high-temperature and high-pressure pipelines of industrial furnaces, central heating system pressure components, and even structural parts of construction and engineering machinery (when low-temperature toughness requirements are met) <superscript>4<superscript>8.
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What is P265GH?
P265GH is a European standard pressure vessel steel grade specified in EN 10028-2. It is a non-alloy structural steel with good weldability, high temperature resistance and pressure-bearing capacity, widely used in boiler and pressure vessel manufacturing.
Which standard defines P265GH?
P265GH is mainly defined by the European standard EN 10028-2, which specifies the technical delivery conditions for non-alloy and alloy steels for pressure purposes. This standard regulates its chemical composition, mechanical properties and inspection methods.
What are the main chemical components of P265GH?
The main chemical components of P265GH include C (≤0.20%), Si (≤0.35%), Mn (1.00-1.60%), P (≤0.025%), S (≤0.015%), and trace elements like Ni, Cr, Mo, ensuring its structural and functional stability.
What are the mechanical properties of P265GH?
P265GH has a yield strength of ≥265 MPa (at room temperature), tensile strength of 410-530 MPa, elongation after fracture of ≥24%, and good impact toughness, suitable for bearing pressure and high-temperature environments.
What is the maximum operating temperature of P265GH?
The maximum continuous operating temperature of P265GH is generally around 400-450°C. Beyond this range, its mechanical properties may decrease, affecting the safety and service life of equipment made from it.
Is P265GH weldable?
Yes, P265GH has excellent weldability. It can be welded using common methods such as arc welding, gas welding and resistance welding without preheating under normal thickness, but proper post-weld heat treatment may be needed for thick workpieces.
What are the typical applications of P265GH?
P265GH is widely used in manufacturing boilers, pressure vessels, heat exchangers, steam pipes and other equipment that work under medium temperature and pressure, especially in petroleum, chemical and power industries.
What is the difference between P265GH and P235GH?
The main difference lies in yield strength: P265GH has a yield strength of ≥265 MPa, while P235GH is ≥235 MPa. P265GH also has higher tensile strength, making it more suitable for equipment requiring higher pressure-bearing capacity.
Does P265GH require heat treatment?
P265GH is usually supplied in the normalized state (heat treatment at 890-950°C and air cooling). For thick-walled components or after welding, stress relief annealing may be required to eliminate internal stress and improve material toughness.
What is the thickness range of P265GH plates?
The common thickness range of P265GH plates is 6-200 mm. For thicknesses exceeding 100 mm, stricter inspection standards (such as ultrasonic testing) are required to ensure no internal defects affecting performance.