Is SPV355 a low-alloy steel?

SPV355 is a high-quality pressure vessel steel plate renowned for its excellent comprehensive mechanical properties. It is mainly applied in manufacturing various pressure-bearing equipment and components, featuring high yield strength, good low-temperature toughness, and superior weldability. This steel grade strictly complies with relevant international and industrial standards for pressure vessel materials, ensuring safe and stable operation in harsh working environments involving high temperature and pressure.

Key Advantages

High Load-Bearing Capacity: Its high yield and tensile strength allow for the construction of thinner, lighter pressure vessels while maintaining the same safety standards as thicker, conventional steels.

Exceptional Toughness: The material exhibits excellent resistance to brittle fracture, ensuring the vessel can absorb energy and resist cracking even under sudden pressure changes or mechanical impact.

Superior Weldability: Low carbon equivalent levels make it highly compatible with various welding techniques. It resists cold cracking in the heat-affected zone, which simplifies the assembly of complex, large-scale structures.

Thermal Stability: It is specifically engineered to retain its mechanical properties at intermediate temperatures, preventing significant deformation or loss of strength during continuous heat exposure in boilers.

Formability: Despite its strength, SPV355 can be cold-formed or hot-rolled into the curved shapes required for spherical tanks and cylindrical shells.

High Purity: Stringent manufacturing standards limit impurities like sulfur and phosphorus, leading to a cleaner internal structure and better overall reliability in critical service.

application 

Core Industrial Sectors

Petrochemical & Chemical Industry: This is the primary sector for SPV355, where it is used to fabricate high-pressure reactors, heat exchangers, and separators. It is also the standard choice for spherical storage tanks and oil storage facilities.

Power Generation (Thermal & Nuclear): It is used for critical boiler components, including boiler steam drums, super-heaters, and containment canisters in nuclear facilities.

Hydropower: Engineers specify SPV355 for high-pressure water pipelines, turbine scroll cases, and Francis turbines.

Specific Equipment Uses

Storage Vessels: Specialized liquefied petroleum gas (LPG) cylinders and gas cans designed for safe transport and stationary storage.

Infrastructure Components: Structural beams and wall panels within industrial plants that require high yield strength.

Fluid Transport: Heavy-duty pipes for hot liquids and high-pressure steam distribution.

Typical Service Environments

The steel is chosen for "intermediate temperature service," meaning it reliably operates in heat-intensive zones where standard carbon steel might suffer from thermal stress or brittle fracture.

Key Reasons to Use SPV355 

Outstanding Mechanical Properties

It balances high tensile strength (≥355 MPa) and excellent low-temperature toughness, resisting brittle fracture even at -20℃. Its stable yield strength and elongation ensure structural integrity under medium-to-high pressure loads, meeting rigorous safety standards for pressure vessels.

Superior Weldability

With optimized carbon equivalent and controlled impurity content (P≤0.025%, S≤0.015%), it avoids welding cracks during fabrication. Minimal preheating requirements and compatibility with common welding methods (arc welding, gas welding) reduce production complexity and cost.

Strong Environmental Adaptability

It withstands long-term operation in temperatures ranging from -20℃ to 450℃ and resists mild corrosion from oil, gas and steam. This adaptability eliminates the need for excessive anti-corrosion treatment in non-strongly corrosive environments, cutting maintenance costs.

Cost-Effective and Reliable

As a cost-efficient alternative to high-alloy steels, it delivers reliable performance for petrochemical, energy and infrastructure projects, ensuring long service life and low failure risks.

Contact now

If you have project requirements for SPV355, we welcome your inquiry. GNEE maintains a large inventory of commonly used high strength steel grades for your selection.For detailed mechanical properties, chemical composition, and technical data, as well as free samples, please contact our factory immediately. We offer competitive prices, stable quality, and professional service. Email:beam@gneesteelgroup.com.

Which standards does SPV355 comply with?

SPV355 mainly complies with the Japanese industrial standard JIS G 3115. This standard specifies the technical requirements, chemical composition, mechanical properties, inspection methods and delivery conditions of pressure vessel steel plates.

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.

What are the common processing methods for SPV355?

Common processing methods for SPV355 include cutting, bending, welding and machining. Welding is crucial for pressure vessel manufacturing, and SPV355's good weldability ensures firm and leak-proof weld joints after proper welding procedures.

What are the main chemical components of SPV355?

The main chemical components of SPV355 include C (carbon), Si (silicon), Mn (manganese), P (phosphorus), S (sulfur), etc. P and S are harmful impurities with strict content limits to ensure the steel's performance and safety in pressure environments.

What is the application field of SPV355?

SPV355 is widely used in manufacturing pressure vessels, such as boilers, chemical reactors, storage tanks, gas cylinders and heat exchangers. It is also applied in petroleum, chemical, power generation and other industries with high pressure requirements.

What is the tensile strength range of SPV355?

The tensile strength range of SPV355 is 490-630 MPa. This range reflects the steel's ability to resist tensile deformation and fracture, matching its yield strength to meet the structural strength needs of pressure-bearing equipment.

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 minimum yield strength of SPV355?

The minimum yield strength of SPV355 is 355 MPa, which is the key index determining its pressure-bearing capacity. This strength level ensures the steel can withstand high internal pressure without deformation or failure in pressure vessel applications.