Gnee Steel is a leading wholesaler, vendor, merchant, and exporter of ASTM A387 GR 11 CL 2 Plates. We also manufacture stainless steel, high nickel alloys, and carbon steel. 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. CL 2 plates are constructed in various forms such as foils, coils, perforated sheets, chequered plates, strips, flat, blank, ring, shim sheets, rolls, and plain sheets. Alloy Gr 11 CL 2 is specified with a higher elongation, yield power, strong tensile point, and many more.
ASME SA387 Grade 11 Class 2 Alloy Steel Plates
ASME SA387 Grade 11 Class 2 is a high-quality chromium-molybdenum (Cr-Mo) alloy steel plate specifically designed for use in weldable pressure vessels, boilers, and heat exchangers. This grade is optimized for elevated temperature service, where maintaining structural integrity and resisting oxidation are critical requirements.
Material Characteristics
Alloy Composition: Contains nominally 1.25% Chromium and 0.5% Molybdenum. The chromium provides essential corrosion and oxidation resistance, while the molybdenum enhances tensile strength and resistance to "creep" (deformation under long-term thermal stress).
Class 2 Designation: As a Class 2 material, it is supplied in the normalized and tempered condition. It features a higher tensile and yield strength than Class 1, allowing for more robust designs in high-pressure environments.
Durability: Offers excellent weldability, sturdiness, and dimensional accuracy. It is highly resistant to stress corrosion cracking, pitting, and crevice corrosion.
Sour Gas Performance: Its specific alloy chemistry makes it a preferred choice for applications in "sour" environments containing hydrogen sulfide
Key Properties:
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)
Tensile Strength: Minimum of 415 MPa (60,000 psi)
Class 2: This classification indicates that the material has undergone additional heat treatment, enhancing its properties compared to Class 1, which may not have the same level of treatment. Class 2 is intended for applications requiring greater performance under higher stress and temperature conditions.
Primary Industrial Applications
Due to its heat resistance and mechanical toughness, Grade 11 Class 2 is utilized across a wide range of demanding sectors:
Energy & Petrochemical: Used in the fabrication of reactors, synthesis towers, heat exchangers, and separators for oil and gas processing.
Power Generation: Essential for high-temperature boilers, pressure headers, and steam piping systems.
Marine & Infrastructure: Applicable in port building, shipbuilding, and infrastructure where high-strength structural steel is required.
Industrial Processing: Found in the paper, pulp, sugar, and wastewater management industries, especially in equipment that handles high-temperature liquids.
Manufacturing: Used for flanges, valves, pipe clamps, and specialized components in nuclear and aerospace plants.
Equivalents
| BS | EN | ASTM/ASME | DIN |
| 621 B | ––– | SA387-11-2 | ––– |
Chromium & Molybdenum content
| Designation | Nominal Chromium Content (%) |
Nominal Molybdenum Content (%) |
| SA387 Grade 11 | 1.25% | 0.50% |
Tensile Requirements for ASME SA387 Grade 11 Alloy Steel Plates Class 2 Plates
| Designation: | Requirement: | Grade 11 |
| SA387 Grade 11 | Tensile strength, ksi [MPa] | 75 to 100 [515 to 690] |
| Yield strength, min, ksi [MPa]/(0.2% offset) | 43 [310] | |
| Elongation in 8 in. [200mm], min % | 18 | |
| Elongation in 2 in. [50mm], min, % | 22 | |
| Reduction of area, min % | ––– |
ASME SA387 Grade 11 Class 2 Chemical Composition
| Grade | C | Mn | P | S | Si | Cr | Mo |
| A387 Gr.11 | 0.05-0.17 | 0.40-0.65 | 0.035 | 0.035 | 0.50-0.80 | 1.00-1.50 | 0.45-0.65 |
1 What is ASME SA387 Grade 11 Class 2 material?
ASME SA387 Grade 11 Class 2 is a chromium-molybdenum alloy steel plate designed for elevated temperature service in welded boilers and pressure vessels, featuring ~1.25% Chromium and ~0.50% Molybdenum for enhanced high-temperature strength, oxidation, and corrosion resistance, with "Class 2" indicating higher tensile strength requirements than Class 1 due to specific heat treatment, common in oil, gas, and power industries.
2 What is ASME SA387 Grade 11 Class 2 equivalent to?
ASME SA387 Grade 11 Class 2 is a chromium-molybdenum alloy steel for high-temperature pressure vessels, equivalent to ASTM A387 Grade 11 Class 2 and often cross-referenced with BS 621B, with Class 2 indicating specific higher tensile strength requirements compared to Class 1. Its nominal composition is ~1.25% Chromium and ~0.50% Molybdenum, offering good oxidation/corrosion resistance.
3What temperature is ASME SA387 Grade 11 Class 2?
ASME SA387 Grade 11 Class 2 is a chromium-molybdenum alloy steel designed for elevated temperatures, used in pressure vessels and boilers for high-heat applications like refineries, offering good corrosion resistance. While it's used up to high temperatures (often over 300°C/572°F), its specific allowable temperatures depend on the design code, with charts showing its suitability well into the hundreds of degrees Fahrenheit (e.g., up to 375°F in some tables, but generally for higher service temps).
4What is the hardness of ASME SA 387 Grade 11 Class 2
ASME SA 387 Grade 11 Class 2 steel is typically specified by its tensile strength (515-690 MPa or 75-100 ksi) and yield strength (min 310 MPa or 43 ksi), not a specific hardness value, but its hardness is related to these properties, usually tested as Brinell (HBW) and falling in a range consistent with its heat treatment (normalized and tempered) for high-temperature service, around 250 HBW or less. The material's hardness is a consequence of its composition (Cr-Mo alloy) and controlled heat treatment, making it suitable for pressure vessels.
5What are the typical application fields of ASME SA 387 Grade 11 Class 2
ASME SA 387 Grade 11 Class 2 is a chrome-moly alloy steel for high-temperature pressure vessels, primarily used in the oil, gas, and petrochemical industries for equipment like boilers, heat exchangers, piping, and storage tanks handling hot liquids and gases, especially in sour (corrosive) service due to its excellent oxidation and corrosion resistance from chromium content.
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