P355GH is a non-alloy pressure vessel steel produced according to the European standard EN 10028-2, specifically designed for use in elevated temperature environments. It is characterized by excellent weldability and high toughness.
P355GH Chemical Composition
|
|
|||||||
|
Grade |
The Element Max (%) |
||||||
|
C |
Si |
Mn |
P |
S |
Al(min) |
N |
|
|
P355GH |
0.10-0.22 |
0.60 |
1.10-1.70 |
0.025 |
0.015 |
0.020 |
0.012 |
|
Cr |
Cu |
Mo |
Nb |
Ni |
Ti |
V |
|
|
0.30 |
0.30 |
0.08 |
0.040 |
0.30 |
0.03 |
0.02 |
|
P355GH Mechanical Property
|
Grade |
|
P355GH Mechanical Property |
|||||
|
Thickness |
Yield |
Tensilmie |
Elongation |
Impact Energy(KV J) min |
|||
|
P355GH |
mm |
Min Mpa |
Mpa |
Min % |
-20° |
0° |
+20° |
|
≤ 16 |
355 |
510-650 |
20 |
27 |
34 |
40 |
|
|
16> to ≤40 |
345 |
510-650 |
20 |
27 |
34 |
40 |
|
|
40> to ≤60 |
335 |
510-650 |
20 |
27 |
34 |
40 |
|
|
60> to ≤100 |
315 |
490-630 |
20 |
27 |
34 |
40 |
|
|
100> to ≤150 |
295 |
480-630 |
20 |
27 |
34 |
40 |
|
|
150> to ≤250 |
280 |
470-630 |
20 |
27 |
34 |
40 |
|
Equivalent Grades
P355GH has several equivalent grades in various international standards:
USA (ASTM/ASME): ASTM A516 Grade 70 / ASME SA516 Grade 70
Germany (DIN): 19Mn6
Japan (JIS): SPV 36
China (GB): Q345R
Adopted Processes for P355GH Steel
P355GH, a normalized pressure vessel steel, adopts mature and standardized manufacturing and processing technologies to ensure its mechanical properties and application reliability. The key adopted processes are as follows:
Normalizing Heat Treatment: As the core base material process, it involves heating the steel to 880–950°C, holding it at a constant temperature for sufficient time to achieve uniform austenitization, and then air-cooling. This process refines the grain structure, enhances toughness and strength, and lays a solid foundation for the steel's pressure-bearing performance.
Hot Forming Process: Hot rolling, forging and hot bending are mainly adopted, with the working temperature controlled at 850–1100°C. The steel shows good plasticity at this temperature, facilitating the forming of pressure vessel shells, headers and other components. Air cooling is used after forming to maintain structural stability.
Welding Process: Common arc welding technologies (MIG/MAG, TIG, SMAW) are adopted. For thin plates (≤16mm), no preheating is required; for thick plates (>16mm), preheating to 80–150°C is performed. Post-weld heat treatment is only necessary for heavy-walled high-pressure parts, ensuring weld quality and avoiding cracking.
Machining & Cold Working: Turning, milling, drilling and other machining processes are used for precision shaping. Moderate cold bending and flanging are allowed; preheating (150–250°C) is required for large deformation to prevent residual stress and cold cracking.
All processes are compatible with industrial production standards, ensuring the steel meets the requirements of pressure-bearing equipment manufacturing.
Advantages of P355GH Steel
P355GH is a preferred material for pressure-bearing equipment in multiple industries due to its comprehensive performance advantages. The key advantages are as follows:
Excellent Mechanical Properties: It has stable tensile strength, yield strength and high toughness, especially maintaining good impact resistance at low temperatures (-20°C). This enables it to withstand long-term high-temperature and high-pressure conditions without brittle fracture, ensuring the safe operation of pressure vessels and boilers.
Superior Weldability: It is compatible with common arc welding processes (MIG/MAG, TIG, SMAW) without complex preheating or post-weld heat treatment for general applications. The weld joints have high strength and good toughness, reducing fabrication difficulty and production costs.
Good Formability: It performs well in both hot and cold forming processes. With excellent plastic deformability at high temperatures and moderate cold workability, it can be easily shaped into various components (shells, headers, heads) to meet diverse manufacturing needs of industrial equipment.
Stable Thermal Stability: It has strong resistance to thermal fatigue and thermal aging, maintaining structural and performance stability under long-term continuous high-temperature (up to 400°C) operation. It is not prone to performance degradation, extending the service life of equipment.
Wide Applicability & Standard Compliance: Compliant with European EN standards, it is suitable for multiple media (water, steam, oil, etc.) and industries (petrochemical, power generation, etc.). Its mature supply chain and standardized processing make it cost-effective and widely available.
If you want to learn more about GNEE's products, you can send an email to beam@gneesteelgroup.com. We are more than happy to assist you.
What is the delivery condition of P355GH?
P355GH is usually delivered in hot-rolled, normalized or normalized rolled condition. The delivery condition is specified in the order, and the manufacturer must provide a test report confirming mechanical and chemical properties.
How to test the impact toughness of P355GH?
The impact toughness of P355GH is tested by Charpy V-notch impact test. Samples are taken from the material, and the impact energy is measured at specified temperatures (usually 20°C or -20°C) to evaluate its toughness.
What is the thickness range of P355GH plates?
P355GH plates are commonly available in thickness ranging from 5 mm to 200 mm. For thicker plates, additional heat treatment and testing may be required to ensure uniform mechanical properties throughout the cross-section.
Is P355GH corrosion-resistant?
P355GH has basic corrosion resistance in atmospheric and mild corrosive environments. For harsh environments (e.g., acidic, salty), it needs anti-corrosion treatments like painting, galvanizing or coating to extend service life.
What is the tensile strength range of P355GH?
The tensile strength of P355GH ranges from 470 MPa to 630 MPa, which is higher than ordinary structural steel. This makes it suitable for bearing medium pressure and ensuring structural stability in pressure vessel applications.
Can P355GH be heat-treated?
Yes, P355GH can undergo heat treatments like normalization, annealing and tempering. Normalization improves its grain structure and toughness, while annealing reduces hardness and improves machinability for complex processing.
What is the yield strength of P355GH at high temperatures?
The yield strength of P355GH decreases with increasing temperature. At 300°C, its yield strength is about 280-300 MPa, and at 400°C, it drops to around 220-240 MPa, which must be considered in high-temperature design.
What are the testing requirements for P355GH delivery?
Delivery testing for P355GH includes chemical composition analysis, tensile test, yield strength test, elongation test, impact test and hardness test. Some orders may require additional tests like ultrasonic flaw detection.
What is the density of P355GH?
The density of P355GH is approximately 7.85 g/cm³, the same as ordinary carbon steel. This density value is used in weight calculation, structural design and material selection for pressure vessels and related equipment.
Can P355GH be used to make boilers?
Yes, P355GH is an ideal material for boiler manufacturing. It has good high-temperature resistance, pressure-bearing capacity and weldability, meeting the requirements of boiler drums, headers and heat exchange tubes.