SPV355 is a high-strength steel plate grade standardized under JIS G3115 (Gnee Steel), specifically designed for boilers and pressure vessels operating at intermediate temperatures.
International Equivalents
In global standards, this grade is functionally comparable to:
ASTM (USA): Carbon-manganese-silicon steel for pressure vessels.
EN (Europe): Steel for pressure purposes.
GB (China): High-strength structural steel.
Core Characteristics
High Strength and Resilience: Designed to withstand significant internal pressure without structural failure.
Superior Weldability: Formulated to prevent cracking during industrial welding processes, ensuring the integrity of sealed containers.
Temperature Resistance: Optimized for service at intermediate temperatures, maintaining its mechanical integrity under heat.
SPV355 medium temperature pressure vessel steel chemical composition:(%)
|
Grade |
C |
Mn |
Si |
Al |
P |
S |
|
SPV355 |
≤0.20 |
≤1.60 |
≤0.55 |
0.75 |
≤0.030 |
≤0.030 |
SPV355 pressure vessel steel mechanical property:
|
Grade |
Tensile strength MPa |
Yield strength MPa |
elongation |
|
SPV355 |
520-640 |
≥315 |
≥14 |
SPV355 Production Process
Raw Material Preparation
Select high-purity steel billets with strictly controlled carbon, phosphorus, and sulfur content (P≤0.025%, S≤0.015%), eliminating harmful impurities to lay the foundation for stable mechanical properties.
Homogenization Heating
Charge billets into a walking-beam furnace and heat to 1150–1250°C, holding for a specific duration to ensure uniform internal microstructure and enhanced hot workability.
Controlled Rolling / TMCP
Conduct multi-pass rolling with staged speed and pressure adjustment. Thermo-Mechanical Control Processing refines grain size through deformation and phase transformation synergy, boosting strength and toughness.
Heat Treatment
Perform normalizing at 880–920°C followed by air cooling to homogenize the ferrite-pearlite structure. For higher performance demands, adopt quenching-tempering (Q+T) to optimize hardness and impact resistance.
Finishing & Inspection
Carry out surface descaling, straightening, and ultrasonic flaw detection to ensure compliance with pressure vessel steel quality standards.
Applications of SPV355
Petrochemical Equipment
Fabricate reactors, storage tanks and heat exchangers, withstanding high pressure and corrosive mediums in oil refining and chemical production.
Energy Industry
Manufacture boiler drums and pressure vessels for thermal power plants, adapting to high-temperature and high-pressure operating conditions.
General Pressure Vessels
Produce mid-to-high pressure tanks for gas storage and liquid transportation, ensuring safe and stable operation under variable working environments.
Packing
1.Seaworthy Packaging: We use strong, durable materials such as wooden pallets or crates to ensure the steel plates are securely packed for long sea voyages, preventing damage from movement.
2.Waterproof Wrapping: P420M is covered with high-quality waterproof materials to protect it from moisture and corrosion during transport, especially in humid environments.
3.Edge and Surface Protection: We apply edge protectors and use padded coverings to safeguard the steel from scratches and dents, ensuring that the material's surface and edges remain intact.
4.Custom Labeling and Marking: All shipments are clearly labeled with handling instructions and customer-specific requirements, facilitating smooth customs clearance and proper storage upon arrival.
Full specification and details are available on request. The above information is provided for guidance purposes only. For specific design requirements please contact our technical sales staff.
What is the thickness range of SPV355 steel plates?
The common thickness range of SPV355 steel plates is 6-200 mm. Different thicknesses are selected according to the pressure level and structural design of the pressure vessel, with thicker plates used for higher pressure applications.
Is SPV355 corrosion-resistant?
SPV355 has basic corrosion resistance in ordinary environments, but it is not suitable for strong corrosive media. In corrosive working conditions (such as chemical media), it needs anti-corrosion treatment like coating, galvanizing or lining to extend service life.
What is the difference between SPV355 and Q345R?
SPV355 (JIS standard) and Q345R (Chinese standard GB 713) are both pressure vessel steels. SPV355 has a higher minimum yield strength (355 MPa vs 345 MPa) and slightly different chemical composition, adapting to different regional standard requirements.
How to inspect the quality of SPV355 steel plates?
Quality inspection of SPV355 includes chemical composition analysis (by spectroscopy), mechanical property testing (tensile, impact, bending tests), non-destructive testing (ultrasonic, magnetic particle, penetrant testing) to ensure compliance with standards.
Can SPV355 be used for high-pressure boilers?
Yes, SPV355 can be used for manufacturing medium and high-pressure boiler components (such as boiler drums, headers). Its high strength and good heat resistance meet the requirements of boiler working conditions with high temperature and pressure.
What is the delivery state of SPV355?
The common delivery state of SPV355 is hot-rolled, normalized or tempered. Normalized state is preferred for pressure vessel applications, as it refines the grain structure, improves toughness and ensures uniform mechanical properties.
Does SPV355 have good formability?
SPV355 has good formability, which can be easily bent, stamped and shaped into various pressure vessel components. Its moderate hardness and toughness balance ensure no cracks or damage during the forming process.
What is the maximum pressure SPV355 can bear?
The maximum bearing pressure of SPV355 depends on its thickness, structural design and working temperature. Generally, it can be used in pressure vessel systems with working pressure up to 10 MPa after proper calculation and design.
Is SPV355 suitable for offshore oil and gas equipment?
Yes, SPV355 is suitable for some offshore oil and gas equipment (such as onshore storage tanks and pipelines connected to offshore platforms) after anti-corrosion treatment, due to its good pressure-bearing capacity.
What welding materials are suitable for SPV355?
Suitable welding materials for SPV355 include E50 series electrodes (such as E5015, E5016) for manual arc welding, and ER50-6 welding wire for gas metal arc welding (GMAW), ensuring matching mechanical properties with the base metal.