A387 Grade 11 Class 1 pressure vessel steel plate is a chromium-molybdenum alloy steel specifically developed for welded pressure vessels and boilers operating under elevated temperature conditions.
As a professional steel plate manufacturer and global supplier, GNEE Steel supplies ASTM A387 Grade 11 Class 1 plates with stable chemistry, reliable mechanical performance, and full inspection support.
A387 Grade 11 Class 1 pressure vessel steel plate
Within the first 100 words, it is essential to clarify that GNEE is a manufacturer, not a simple trading company. We operate with strong production capacity, advanced heat treatment facilities, and strict quality control systems.
Our A387 Gr11 Cl1 pressure vessel steel plates are widely supplied to EPC contractors and fabricators in energy, petrochemical, and industrial construction projects worldwide.
A387 Grade 11 Class 1 Steel Plate Production Size & Supply Capacity
GNEE Steel offers large-size and thick-section production capability, making our A387 Grade 11 Class 1 plates suitable for heavy-duty pressure vessel fabrication.
Production size range:
Thickness: 4 mm – 400 mm
Width: 1000 mm – 4000 mm
Length: 4000 mm – 12000 mm
Production capacity:
Monthly output up to 10,000 tons
This wide size range allows customers to reduce welding seams, improve fabrication efficiency, and enhance overall equipment reliability.
A387 Grade 11 Class 1 Steel Plate Manufacturing Process & Heat Treatment
A387 Grade 11 Class 1 pressure vessel steel plates are produced under controlled processes to ensure consistent performance across the entire plate thickness.
Production methods include:
- Hot Rolled
- Annealing
- Normalizing
- Tempering
Available heat treatment options:
- Normalized (N)
- Quenched and Tempered (Q+T)
- Impact Test
- HIC Test (optional, if required by project rules)
These processes ensure fine grain structure, stable tempering behavior, and excellent weldability for pressure equipment fabrication.
Chemical Composition of A387 Grade 11 Class 1 Pressure Vessel Steel Plate
The chemical composition of A387 Grade 11 Class 1 steel plate is strictly controlled to balance strength, corrosion resistance, and high-temperature stability.
Chemical Composition Table (%)
| Element | Composition |
|---|---|
| Carbon (C) | 0.05 – 0.17 |
| Manganese (Mn) | 0.40 – 0.65 |
| Silicon (Si) | 0.15 – 0.40 |
| Phosphorus (P) | ≤ 0.035 |
| Sulfur (S) | ≤ 0.035 |
The chromium-molybdenum alloy system provides:
Improved oxidation resistance
Enhanced corrosion resistance
Stable performance in elevated temperature service
Mechanical Properties of A387 Grade 11 Class 1 Steel Plate
A387 Grade 11 Class 1 pressure vessel steel plates are designed to meet strict mechanical requirements for load-bearing and pressure containment.
Mechanical Properties Table
| Property | Requirement |
|---|---|
| Tensile Strength | 60–85 ksi / 415–585 MPa |
| Yield Strength (min) | 35 ksi / 240 MPa |
| Elongation | 19% |
| Impact Test | Optional (as required) |
These mechanical properties ensure safe operation under pressure and thermal stress over long service periods.
Applications of A387 Grade 11 Class 1 Pressure Vessel Steel Plate
A387 Grade 11 Class 1 steel plates are mainly used in construction and fabrication of pressure vessels, especially in high-temperature service environments.
Typical applications include:
- Pressure vessels and reactors
- Industrial boilers and boiler drums
- Heat exchangers
- Oil & gas processing equipment
- Petrochemical plant installations
This grade is particularly suitable where both strength and corrosion resistance are required.
Why Choose GNEE for A387 Grade 11 Class 1 Steel Plate
GNEE Steel is recognized as one of the most competitive manufacturers and suppliers of ASTM A387 Grade 11 Class 1 pressure vessel steel plate in China.
Our advantages include:
- Large production size capability
- Stable monthly supply capacity
- Multiple heat treatment options
- Strict quality inspection and testing
- Fast response and professional technical support
Each order is supplied with complete documentation to ensure compliance with ASTM A387 / A387M standards.
As an experienced manufacturer, GNEE Steel supplies A387 Grade 11 Class 1 pressure vessel steel plate with consistent quality, large-size capability, and dependable delivery for global pressure vessel projects.
Contact us for the latest A387 Grade 11 Class 1 pressure vessel steel plate price list, technical datasheet, and production schedule.
Contact us for latest A387 Grade 11 Class 1 pressure vessel steel plate price list
What is ASTM A387 material?
ASTM A387 GR. 91 CL. 2 Alloy Steel Plates manufactured at the world's finest steel mills, this molybdenum-chrome based alloy has excellent resistance to greater working temperatures, making it the right selection for various applications like in gas, oil, chemical, and power generation.
What is ASTM A387 Grade 11 equivalent to?
ASTM A387 grade 11 equivalent steel is ASME SA387 grade 11. ASTM A387 grade 11 covers A387 grade 11 class 1 and A387 grade 11 class 2, which are equivalent to ASME SA387 grade 11 class 1 and SA387 grade 11 class 2 respectively.
What is the difference between ASTM A182 and A387?
A387 is Plate material. A182 is Forging material. You can refer relevant ASTM Book of standards.
What is ASTM A387?
The ASTM A387 specification is the Standard Specification for Pressure Vessel Plates, Alloy Steel, Chromium-Molybdenum plates used in the application of welded boilers and pressure vessels subjected to elevated temperatures. The two grades SSAB produces are available as Class 1 and/or Class 2.