5 Reasons to Choose ASTM A387 Grade 11 Steel for High-Temperature Pressure Vessels

Nov 10, 2025 Leave a message

ASTM-A387-A387M.pdf

ASTM A387 Grade 11 is a chromium-molybdenum alloy steel specifically designed for high-temperature pressure vessel applications.

Below are five key reasons to choose ASTM A387 Grade 11 steel for your high-temperature projects:

 

High-Temperature Strength

 

ASTM A387 Grade 11 steel

 

Yield Strength (ReH): ≥ 205 MPa (30,000 psi)

Tensile Strength (Rm): 415–585 MPa (60,000–85,000 psi)

Benefits:

Maintains structural integrity at elevated temperatures (up to 595°C or 1100°F).

Ideal for boilers, heat exchangers, and reactors operating under high thermal stress.

 

Excellent Creep Resistance

 

 

Creep Strength: High resistance to deformation under prolonged stress at high temperatures.

Benefits:

Extends the service life of pressure vessels in high-temperature environments.

Reduces the risk of failure due to creep-induced cracking.

 

Superior Weldability

 

ASTM A387 Grade 11 steel

 

Preheating: 150–200°C (300–400°F) for thicknesses ≥ 25 mm.

Welding Methods: Use low-hydrogen electrodes (e.g., AWS E8018-B2).

Benefits:

Minimizes the risk of weld cracking and hydrogen-induced cracking (HIC).

Simplifies fabrication and repair processes.

 

Corrosion and Oxidation Resistance

 

 

Chromium Content: 1.00–1.50%

Molybdenum Content: 0.45–0.65%

Benefits:

Resists oxidation and scaling at high temperatures.

Suitable for environments with moderate sulfur and hydrogen exposure.

 

Compliance with Industry Standards

 

ASTM A387 Grade 11 steel

 

Standards: ASTM A387/A387M, ASME Section VIII.

Certifications: EN 10204 3.1/3.2 mill certificates available.

Benefits:

Ensures compliance with global pressure vessel codes.

Facilitates international trade and project approvals.

 

Applications

 

 

Power Generation: Boilers, superheaters, and steam drums.

Oil & Gas: Reactors, separators, and heat exchangers.

Chemical Processing: Pressure vessels for high-temperature chemical reactions.

 

Case Study: ASTM A387 Grade 11 in Power Plant Boilers

 

 

ASTM A387 Grade 11 steel

Challenge: Reduce boiler weight while maintaining high-temperature performance.

Solution: Use ASTM A387 Grade 11 steel for boiler drums and headers.

Result: 20% weight reduction, enabling higher efficiency and lower fuel consumption.

 

Request A Quote

 

If you want to learn more about GNEE's products, you can send an email to alloy@gneesteelgroup.com. We are more than happy to assist you.

 

FAQ

Q: What is A387 Grade 11 material?

A: The ASTM A387 specification is the Standard Specification for Pressure Vessel Plates, Alloy Steel, Chromium-Molybdenum intended primarily for use in welded boilers and pressure vessels designed for elevated temperature service.

Q: What is SA 387 GR 11 Cl 1 equivalent material?

A: Sa 387 Gr 11 Equivalent Material
With similar chromium, molybdenum, and chemical content the, Sa 387 Gr 11 Cl 1 Equivalent Material of the BS 621B exhibits identical properties.

Q: What temperature is SA 387 GR 11?

A: In the lower end of the temperature range SA 387 Gr 11 (1150 °F min tempering temperature) , and SA 387 Gr 22 (1250 °F min tempering temperature) are used. These grades can be specified in either class 1 or 2 and can also be provided in the Normalized & Tempered or Quenched and Tempered.

Q: What is the difference between SA 387 GR 11 cl1 and cl2?

A: The difference between SA 387 Grade 11 Class 1 and Class 2 Plate lies in their mechanical properties. However, they both have the same chemical composition. The tensile strength and yield strength of class 2 material is higher than that of class 1, whereas the elongation for class 1 is higher compared to class 2.

Q: What is SA 387 Grade 11 material?

A: Composition: ASME SA387 Grade 11 typically contains about 1% chromium and 0.5% molybdenum. This composition provides good strength and resistance to oxidation at high temperatures. Mechanical Properties: Yield Strength: Minimum of 205 MPa (30,000 psi)

Q: What is the difference between SA 387 Grade 11 CL 1 and Class 2?

A: The Chemical Composition remains the same in both Class 1 and Class 2 (Cl1 and Cl2) but the only Difference is in the Mechanical Properties which is mentioned in below Table.

Q: What is SA 387 Grade 11 Class 2 equivalent to?

A: Sa 387 Gr 11 Equivalent Material is the ASME SA387 in the US markets with the European Union having modules in 13CrMoSi5-5 grade. The Sa 387 Gr 11 Cl 2 Equivalent Material is the SA387-11-2 of the ASME and ASTM standard.

Q: What temperature is SA 387 GR 11?

A: In the lower end of the temperature range SA 387 Gr 11 (1150 °F min tempering temperature) , and SA 387 Gr 22 (1250 °F min tempering temperature) are used. These grades can be specified in either class 1 or 2 and can also be provided in the Normalized & Tempered or Quenched and Tempered.

Q: What is the chemical composition of ASTM A387 Grade 11 Class 2?

A: ASTM A387 GR 11 CL 2 Plates is designed with the composition of chemicals such as carbon, silicon, phosphorous, chromium, sulfur, molybdenum, and manganese. Alloy ASTM A387 is made with specifications such as different standards, finishing, hardness, form, width, and thickness.

Q: What is the difference between SA 516 GR 70 and SA 387 GR 11?

A: Compared to carbon steel plates, SA 387 Gr 11 plates offer superior corrosion and oxidation resistance while maintaining good tensile and yield strength. Compared to SA 516 Gr 70 plates, SA 387 Gr 11 plates have better resistance to oxidation and corrosion, making them a better choice for high-temperature environments.

 

Grades Of Pressure Vessel Plates Supplied By GNEE
ASTM ASTM A202/A202M ASTM A202 Grade A ASTM A202 Grade B    
ASTM A203/A203M ASTM A203 Grade A ASTM A203 Grade B ASTM A203 Grade D ASTM A203 Grade E
ASTM A203 Grade F      
ASTM A204/A204M ASTM A204 Grade A ASTM A204 Grade B ASTM A204 Grade C  
ASTM A285/A285M ASTM A285 Grade A ASTM A285 Grade B ASTM A285 Grade C  
ASTM A299/A299M ASTM A299 Grade A ASTM A299 Grade B    
ASTM A302/A302M ASTM A302 Grade A ASTM A302 Grade B ASTM A302 Grade C ASTM A302 Grade D
ASTM A387/A387M ASTM A387 Grade 5 Class1 ASTM A387 Grade 5 Class2 ASTM A387 Grade 11 Class1 ASTM A387 Grade 11 Class2
ASTM A387 Grade 12 Class1 ASTM A387 Grade 12 Class2 ASTM A387 Grade 22 Class1 ASTM A387 Grade 22 Class2
ASTM A515/A515M ASTM A515 Grade 60 ASTM A515 Grade 65 ASTM A515 Grade 70  
ASTM A516/A516M ASTM A516 Grade 55 ASTM A516 Grade 60 ASTM A516 Grade 65 ASTM A516 Grade 70
ASTM A517/A517M ASTM A517 Grade A ASTM A517 Grade B ASTM A517 Grade E ASTM A517 Grade F
ASTM A517 Grade P ASTM A517 Grade J    
ASTM A533/A533M ASTM A533 Grade A Class1 ASTM A533 Grade B Class1 ASTM A533 Grade C Class1 ASTM A533 Grade D Class1
ASTM A533 Grade A Class2 ASTM A533 Grade B Class2 ASTM A533 Grade C Class2 ASTM A533 Grade D Class2
ASTM A533 Grade A Class3 ASTM A533 Grade B Class3 ASTM A533 Grade C Class3 ASTM A533 Grade D Class3
ASTM A537/A537M ASTM A537 Class1 ASTM A537 Class2 ASTM A537 Class3  
ASTM A612/A612M ASTM A612      
ASTM A662/A662M ASTM A662 Grade A ASTM A662 Grade B ASTM A662 Grade C  
EN EN10028-2 EN10028-2 P235GH EN10028-2 P265GH EN10028-2 P295GH EN10028-2 P355GH
EN10028-2 16MO3      
EN10028-3 EN10028-3 P275N EN10028-3 P275NH EN10028-3 P275NL1 EN10028-3 P275NL2
EN10028-3 P355N EN10028-3 P355NH EN10028-3 P355NL1 EN10028-3 P355NL2
EN10028-3 P460N EN10028-3 P460NH EN10028-3 P460NL1 EN10028-3 P460NL2
EN10028-5 EN10028-5 P355M EN10028-5 P355ML1 EN10028-5 P355ML2 EN10028-5 P420M
EN10028-5 P420ML1 EN10028-5 P420ML2 EN10028-5 P460M EN10028-5 P460ML1
EN10028-5 P460ML2      
EN10028-6 EN10028-6 P355Q EN10028-6 P460Q EN10028-6 P500Q EN10028-6 P690Q
EN10028-6 P355QH EN10028-6 P460QH EN10028-6 P500QH EN10028-6 P690QH
EN10028-6 P355QL1 EN10028-6 P460QL1 EN10028-6 P500QL1 EN10028-6 P690QL1
EN10028-6 P355QL2 EN10028-6 P460QL2 EN10028-6 P500QL2 EN10028-6 P690QL2
JIS JIS G3115 JIS G3115 SPV235 JIS G3115 SPV315 JIS G3115 SPV355 JIS G3115 SPV410
JIS G3115 SPV450 JIS G3115 SPV490    
JIS G3103 JIS G3103 SB410 JIS G3103 SB450 JIS G3103 SB480 JIS G3103 SB450M
JIS G3103 SB480M      
GB GB713 GB713 Q245R GB713 Q345R GB713 Q370R GB713 12Cr1MoVR
GB713 12Cr2Mo1R GB713 13MnNiMoR GB713 14Cr1MoR GB713 15CrMoR
GB713 18MnMoNbR      
GB3531 GB3531 09MnNiDR GB3531 15MnNiDR GB3531 16MnDR  
DIN DIN 17155 DIN 17155 HI DIN 17155 HII DIN 17155 10CrMo910 DIN 17155 13CrMo44
DIN 17155 15Mo3 DIN 17155 17Mn4 DIN 17155 19Mn6