ASME SA387 Grade 11 Class 2 Steel Plate
ASME SA387 Grade 11 Class 2 (ASTM A387 Grade 11 CL2) is a specification for chromium-molybdenum alloy steel plates intended for use in elevated temperature applications, commonly associated with pressure vessels and heat exchangers. Nominal chrome content at 1.00% to 1.50%, and Moly 0.45% to 0.65% for SA387 GRADE 11 material.
ASME SA387 Grade 11 is a grade specification for low alloy chromium-molybdenum steel sheets, plates and components made our of sheet metal, for use in fabrication of welded boilers and pressure vessels, designated for elevated temperature services. SA387 Grade 11 is further classified into tensile class 1 and class 2.
SA387 Grade 11 Class 2 is a chromium-molybdenum alloy steel plate for high-temperature pressure vessels, boilers, and heat exchangers, offering strength and oxidation resistance due to its ~1.25% chromium and ~0.5% molybdenum content, with Class 2 indicating higher tensile strength (75-100 ksi) compared to Class 1, making it ideal for oil, gas, and petrochemical applications
Key Characteristics:
Corrosion Resistance: High chromium content provides excellent resistance to oxidation and corrosion, suitable for sour gas.
Strength: Class 2 signifies higher tensile strength (515-690 MPa or 75-100 ksi) and yield strength (min 310 MPa or 43 ksi) than Class 1.
Composition: Contains approximately 1.25% Chromium and 0.5% Molybdenum.
Material Type: Chromium-Molybdenum (Cr-Mo) Alloy Steel.
Standards:
Certified to both ASTM A387 and ASME SA387 standards.
Applications:
ASME SA387 Grade 11 Class 2 is commonly used in:
Pressure vessels in the oil and gas industry
Boilers
Heat exchangers
Pipelines and other equipment operating at elevated temperatures
Equivalents
| BS | EN | ASTM/ASME | DIN |
| 621 B | ––– | SA387-11-2 | ––– |
Chromium & Molybdenum content (according to the ASME specification):
| Designation | Nominal Chromium Content (%) | Nominal Molybdenum Content (%) |
|---|---|---|
| A387 Grade 11 | 1.25% | 0.50% |
Tensile Requirements for ASME SA387 Grade 11 Alloy Steel Plates Class 2 Plates
|
|---|
Chemical Requirements for ASME SA387 Grade 11 Alloy Steel Plates
| Element | Chemical Composition (%) | |
| SA387 Grade 11 | ||
| Carbon: | Heat Analysis: | 0.05 - 0.17 |
| Product Analysis: | 0.04 - 0.17 | |
| Manganese: | Heat Analysis: | 0.40 - 0.65 |
| Product Analysis: | 0.35 - 0.73 | |
| Phosphorus: | Heat Analysis: | 0.035 |
| Product Analysis: | 0.035 | |
| Sulphur (max): | Heat Analysis: | 0.035 |
| Product Analysis: | 0.035 | |
| Silicon: | Heat Analysis: | 0.50 - 0.80 |
| Product Analysis: | 0.44 - 0.86 | |
| Chromium: | Heat Analysis: | 1.00 - 1.50 |
| Product Analysis: | 0.94 - 1.56 | |
| Molybdenum: | Heat Analysis: | 0.45 - 0.65 |
| Product Analysis: | 0.45 - 0.70 |
1 What is ASME SA 387 GRADE 11 Class 2 ?
ASME SA 387 Grade 11 Class 2 is a chromium-molybdenum (Cr-Mo) alloy steel plate specification for high-temperature service in pressure vessels and boilers, offering excellent strength, weldability, and resistance to oxidation and corrosion, commonly used in the oil, gas, and petrochemical industries, with typical composition around 1.25% Chromium and 0.50% Molybdenum, and specific tensile/yield strength requirements.
2.What temperature is ASME SA 387 GRADE 11 Class 2?
ASME SA 387 Grade 11 Class 2 steel is designed for elevated temperature service, typically tempered around 1150°F (620°C), making it suitable for boilers, pressure vessels, and piping in high-
heat applications like refineries and power plants, though specific maximum operating temperatures depend on the ASME code section.
3What is the P number of SA 387 GR 11?
The ASME SA-387/ ASTM A387 Gr. 11 steel has the nominal composition of 1.25Cr-0.5Mo-Si with UNS designation number of K11789 and P number of 4.
4What is ASME SA387 Grade 11 Class2 equivalent to?
ASME SA387 Grade 11 is a chromium-molybdenum (Cr-Mo) alloy steel for high-temperature pressure vessels, with equivalents including ASTM A387 Grade 11, European EN 13CrMoSi5-5, and British BS 621B, though EN/DIN often lack direct matches, focusing instead on chemical/mechanical properties. Class 1 and 2 have identical chemistry but differ in mechanical strength, with Class 2 having higher tensile/yield strength for demanding applications.
5What is the hardness of ASME SA387 Grade 11 Class 2?
ASME SA387 Grade 11 Class 2 doesn't have a single hardness value but falls within ranges for tensile/yield strength, typically offering a tensile strength of 75-100 ksi (515-690 MPa) and a minimum yield strength of 43 ksi (310 MPa), reflecting its higher strength compared to Class 1, suitable for high-temp pressure vessels due to its Cr-Mo alloy content, but hardness testing (like Brinell) depends on the specific heat treatment and product form.
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