SA737 Gr.B Steel Plate for Pressure Vessels (ASME)
SA737 Gr.B is an American grade of pressure vessel steel plate under the ASME standard. The manufacturing specification is ASME SA-737/SA-737M, and the ultrasonic testing standard is NB/T 47013.3-2015.
This grade is a carbon-manganese pressure vessel steel with niobium (Cb/Nb) addition, offering good strength and toughness. It is specifically designed for welded pressure vessels. SA737 Gr.B Approximate Grade Lookup Table.
SA737 Gr.B steel plates are impact tested upon agreement. Niobium (Cb) is limited to ≤0.05% for both smelting and finished product analysis.
SA737 Gr.B designation explanation: SA denotes ASME specification, 737 is the specification number, Gr.B denotes Grade B.
Product Overview
SA737 Gr.B Steel Plate is an American grade of pressure vessel steel manufactured in accordance with ASME SA-737/SA-737M. It contains carbon, manganese, and niobium (Cb) as primary alloying elements, providing good weldability, strength, and toughness for welded pressure vessel applications.
This grade offers a minimum yield strength of 345 MPa with tensile strength 485-620 MPa, and higher elongation (≥23% for 2in. gauge length) for improved ductility and formability.
Core Advantages
- Niobium microalloying for grain refinement
- High elongation (≥23% for 2in., ≥18% for 8in.)
- Customizable: impact testing, HIC/SSC
- Good weldability for pressure vessel fabrication
Professional Technical Support and Customization
Comprehensive Knowledge Base: Our sales team is proficient in mainstream domestic and international pressure vessel standards. Whether it's the American ASME standard SA737 Gr.B or other international standards, we can provide accurate technical communication.
Zero Communication Errors: With solid product knowledge, we can avoid all basic errors during the order technical condition confirmation stage, ensuring the accuracy of your order.
Flexible Customization Capabilities: The SA737 Gr.B standard allows niobium addition up to 0.05%. If your design has special requirements (e.g., specific hardness, impact testing, HIC/SSC testing), we support customized production.
Applications
Stock Resources
Plates: 6-100mm+ (W:2000-2500, L:11000-12500)
Hot-rolled plates: 6-40mm (W:1800-2500, L:11000-12500)
Coils: 5-16mm (W:1500-2000)
Spot stock size range and supply conditions
Supply Condition: AR, CR, N
SA737 Gr.B Chemical Composition (max %)
| Element | Smelting Analysis, % | Finished Product Analysis, % |
|---|---|---|
| C, ≤ | 0.2 | 0.22 |
| Mn | 1.15-1.50① | 1.07-1.62① |
| P, ≤ | 0.025 | 0.025 |
| S, ≤ | 0.025 | 0.025 |
| Si | 0.15-0.50 | 0.10-0.55 |
| V | ... | ... |
| Cb (Nb)②, ≤ | 0.05 | 0.05 |
| N, ≤ | ... | ... |
① Under the condition that the carbon content in the smelting analysis does not exceed 0.18%, the maximum manganese content can be increased to 1.60% in the smelting analysis and to 1.72% in the finished product analysis.
② Cb and Nb are the same element, their names are interchangeable, and both names can be used in the A01 standard.
SA737 Gr.B - Alloying Elements and Roles
per ASME SA-737Influences strength and hardness. Smelting ≤0.2%, finished product ≤0.22%.
Enhances strength and toughness. Smelting 1.15-1.50%, finished 1.07-1.62%. Can be increased if C≤0.18%.
Deoxidizer, increases strength. Smelting 0.15-0.50%, finished 0.10-0.55%.
Harmful element, reduces toughness.
Harmful element, causes hot shortness.
Cb and Nb are the same element, their names are interchangeable. Refines grain structure and improves strength. Limited to ≤0.05% for both smelting and finished product analysis.
SA737 Gr.B Mechanical Properties
| Property | Value |
|---|---|
| Yield Strength (MPa), ≥ | 345 |
| Tensile Strength (MPa) | 485-620 |
| Elongation (8in./200mm), ≥, % | 18 |
| Elongation (2in./50mm), ≥, % | 23 |
① For adjustments to elongation, please refer to the A20/A20M standard.
SA737 Gr.B vs Q345R
| Item | SA737 Gr.B | Q345R |
|---|---|---|
| Standard | ASME SA-737 | GB/T 713.2 |
| Yield Strength | ≥345 MPa | ≥345 MPa |
| Tensile Strength | 485-620 MPa | 510-640 MPa |
| Elongation | ≥23% (2in.) / ≥18% (8in.) | ≥21% |
Scenario-Based Recommendation - Grade Comparison
SA738 Gr.B
Elongation ≥20%
SA737 Gr.B
Elongation ≥23% (2in.) / ≥18% (8in.)
Q345R
Charpy 0 C
Quality Control and Inspection
Customizable Specification Range for SA737 Gr.B
Delivery Condition
AR as rolled - CR controlled rolled - N normalized
Additional Requirements
- Simulated post-weld heat treatment (PWHT)
- Brinell hardness requirements
- HIC / SSC testing
- Impact testing per agreement
Other customized technical conditions are also negotiable.
The above ranges represent our standard customizing capability.
Frequently Asked Questions
What is SA737 Gr.B steel plate used for?
SA737 Gr.B steel plate is mainly used for welded pressure vessels, boilers, heat exchangers, storage tanks, and general pressure equipment manufactured under ASME standards.
What is the difference between SA737 Gr.B and SA738 Gr.B?
SA737 Gr.B has yield strength ≥345 MPa and tensile 485-620 MPa, while SA738 Gr.B has higher yield strength ≥415 MPa and tensile 585-705 MPa. SA737 Gr.B contains niobium (Cb) microalloying and offers higher elongation (≥23% for 2in.).
Can the manganese content be increased in SA737 Gr.B?
Yes. Under the condition that the carbon content in the smelting analysis does not exceed 0.18%, the maximum manganese content can be increased to 1.60% in the smelting analysis and to 1.72% in the finished product analysis.
What is the delivery condition for SA737 Gr.B?
SA737 Gr.B is typically delivered in as-rolled (AR), controlled rolled (CR), or normalized (N) condition.
Can you provide SA737 Gr.B steel plates with custom sizes?
Yes. Custom rolling up to 100mm+ thick, 5200mm wide, 18000mm long. Delivery: 15-20 days hot-rolled, 30-35 days normalized.
Request a Quote
Emails go directly to customize@cehesteel.com - reply within 12h.