SA 537 Class 2 is a carbon-manganese steel plate heat-treated (quenched and tempered) for pressure vessel applications. It offers excellent strength, toughness, and weldability, widely used in oil, gas, and petrochemical industries under moderate to severe service conditions.
Global Equivalents
Japan (JIS): G3115 SPV490 (or SPV36).
Europe (EN): EN 10028-3 P460NH.
Germany (DIN): 17155 19Mn6.
Mechanical Properties of ASME SA537 Class 2
| Yield (MPa) | Tensile (MPa) | Elongation A50mm | Elongation A200mm | Thickness |
|---|---|---|---|---|
| 415 | 550/690 | 22% | - | < 65 |
| 380 | 515/655 | 22% | - | > 65 < 100 |
| 315 | 485/620 | 20% | - | > 100 < 150 |
Chemical Composition of ASME SA537 Class 2
| C | 0.24 |
| Si | 0.15/0.50 |
| Mn < 40mm |
0.70/1.35 |
| Mn > 40mm |
1.00/1.60 |
| P | 0.035 |
| S | 0.035 |
| Cr | 0.25 |
| Mo | 0.80 |
| Ni | 0.25 |
| Cu | 0.35 |
Main Applications
Oil, Gas and Petrochemical Industry：Widely used in core equipment such as thick-walled reactors for hydrocracking/hydrotreating, fractionating towers and distillation towers. Also applicable to high-pressure pipelines and header pipes, resisting erosion from high-pressure hydrocarbon media and temperature fluctuation impacts during oil-gas exploration, transportation and refining.
Power Generation Systems：Suitable for key components like high-pressure drums and feedwater heaters in thermal power stations. It can also be used for secondary containment and structural shielding of small modular nuclear reactors, maintaining stable mechanical properties under high-temperature steam circulation and radiation environments.
Cryogenic Storage and Transportation：Due to excellent low-temperature toughness, it is used to manufacture LNG storage tanks, low-temperature transport vessels and API 650/620 standard storage tanks, preventing brittle fracture risks in low-temperature media storage and transportation.
Boilers and Pressure Vessels：Primary material for fusion-welded pressure vessels and boilers, used to store and transport high-pressure gases and liquids, ensuring equipment sealing and structural stability under moderate to high temperatures and pressures.
Offshore Engineering：Applied in offshore platforms and arctic pipelines, adapting to harsh marine environments with high pressure and low temperatures.
Application Conditions
Mechanical Property Requirements：Yield strength ≥415MPa, tensile strength 550-690MPa, elongation ≥22%. Charpy V-notch impact test is mandatory (e.g., ≥20J at -45°C), complying with ASME BPVC Section VIII.
Material and Standard Compliance：Must meet ASME SA 537/SA 537 M standards. Chemical composition is strictly controlled (C≤0.24%, P/S≤0.035% each), with ultrasonic examination per ASME SA-578 Class 1 to ensure no laminations.
Operating Environment Limits：Suitable for temperatures from -68°C (plate thickness ≤65mm) to high-temperature environments with cyclic loading and thermal stress, not applicable to ultra-high temperature (>500°C) or strong corrosion environments beyond its resistance range.
Fabrication Requirements：Welding requires preheating (95-150°C) and post-weld heat treatment (PWHT) with low-hydrogen electrodes (e.g., AWS E7018) to prevent hydrogen cracking. Machinability is suitable for hardness 137-149 HB.
Dimension and Delivery Conditions：Common thickness 6-150mm, width up to 4000mm, length up to 18000mm. Delivered in quenched and tempered (Q+T) state to ensure optimal toughness and ductility.
SA537CL2 Advantages
Superior Mechanical Performance：Delivered in Q+T state with yield strength ≥415MPa and tensile strength 550-690MPa, it has high structural rigidity and load-bearing capacity, matching excellent ductility (elongation ≥22%) to avoid brittle fracture under dynamic load.
Exceptional Low-Temperature Toughness：Passes Charpy V-notch impact test (≥20J at -45°C), maintaining stable toughness at ultra-low temperatures down to -68°C, suitable for cryogenic storage and arctic engineering applications without performance degradation.
Excellent Weldability & Fabricability：Controlled low carbon and impurity content (P/S ≤0.035% each) reduces welding cracking risk; compatible with standard low-hydrogen welding processes, and adaptable to cold/hot forming for different thicknesses, meeting diverse fabrication needs of pressure vessel equipment.
Reliable Structural Stability：Strict ASME SA-578 Class 1 ultrasonic inspection ensures no lamination defects; resists cyclic thermal stress and medium erosion, maintaining long-term structural integrity in high-pressure, high-temperature and alternating temperature working environments.
Standardized & Traceable Quality：Fully compliant with ASME SA537 Class 2 standard, with strictly controlled chemical composition and uniform heat treatment effect, ensuring consistent batch performance and complete quality traceability for industrial mass application.
If you have project requirements for SA537 Class 2, 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.
What are the main chemical compositions of SA 537 Class 2?
The key chemical elements include carbon (0.18-0.25%), manganese (1.00-1.60%), phosphorus (max 0.035%), sulfur (max 0.035%), silicon (0.15-0.40%), nickel (max 0.25%), chromium (max 0.25%), and molybdenum (max 0.08%).
What heat treatment process is required for SA 537 Class 2?
SA 537 Class 2 must undergo quenching and tempering (Q&T) heat treatment. Quenching involves rapid cooling from above the austenitizing temperature, followed by tempering at a controlled temperature to reduce brittleness and optimize toughness.
What is the difference between SA 537 Class 1 and Class 2?
The main difference lies in strength: SA 537 Class 2 has higher yield and tensile strength than Class 1. Class 2 undergoes stricter heat treatment, making it suitable for more demanding pressure and load conditions.
What applications is SA 537 Class 2 commonly used for?
SA 537 Class 2 is widely used in pressure vessels, boilers, storage tanks, and reactor vessels in oil refining, gas processing, petrochemical, and power generation industries, especially for moderate to high-pressure services.
What is the maximum service temperature for SA 537 Class 2?
The maximum recommended service temperature for SA 537 Class 2 is approximately 482°C (900°F). Exceeding this temperature may degrade its mechanical properties, affecting structural integrity in pressure vessel applications.
Is SA 537 Class 2 weldable?
Yes, SA 537 Class 2 is highly weldable. Proper preheating (typically 93-204°C) and post-weld heat treatment (PWHT) are recommended to prevent cold cracking and relieve residual stresses, ensuring sound weld joints.
What is the thickness range available for SA 537 Class 2 plates?
SA 537 Class 2 plates are typically available in thicknesses from 6 mm to 200 mm (0.25 in to 8 in). Thicker plates may require special heat treatment to ensure uniform mechanical properties throughout the cross-section.
Does SA 537 Class 2 require post-weld heat treatment (PWHT)?
Yes, PWHT is generally required for SA 537 Class 2 after welding. It involves heating the weldment to 593-649°C (1100-1200°F) and holding for a specified time to relieve residual stresses and improve weld toughness.
What is the hardness limit for SA 537 Class 2?
The maximum Brinell hardness (HB) for SA 537 Class 2 is 235. Hardness testing is performed to verify the effectiveness of heat treatment and ensure the material does not have excessive brittleness.
What is the minimum yield strength of SA 537 Class 2?
The minimum yield strength of SA 537 Class 2 is 345 MPa (50,000 psi). This high yield strength ensures the material can withstand high pressure and load without permanent deformation in pressure vessel operations.