What temperature is ASTM A387 Grade 22 Class 2 ?
ASTM A387 Grade 22 Class 2 is designed for high-temperature service, maintaining strength up to around 600°C (1112°F), with its tempering heat treatment often occurring around 675°C (1250°F) to provide good high-temperature creep resistance and low-temperature toughness for boilers, pressure vessels, and heat exchangers. Its chromium (2.25%) and molybdenum (1%) content enhance high-temperature strength and corrosion resistance, making it excellent for refining and chemical plants.
ASTM A387 Grade 22 (ASME SA387 Grade 22) is a chromium-molybdenum alloy steel plate intended primarily for welded boilers and pressure vessels designed for elevated temperature and high-pressure service. The chemical composition for SA387 Grade 22 material features a chromium content of 2.00% to 2.50% (nominally 2.25%) and a molybdenum content of 0.90% to 1.10% (nominally 1.00%). The higher concentration of chromium provides enhanced corrosion and oxidation resistance, making the material suitable for storing oil, gas, or other liquids and ensuring compatibility with sour services.
ASME SA387 Grade 22 Class 2 plates are specifically supplied to fabricators serving the oil, gas, and petrochemical industries. These sectors require a pressure vessel grade steel that maintains structural integrity and performs reliably in elevated temperatures. Due to the balanced alloy content, SA387 Grade 22 Class 2 serves this purpose effectively, offering a robust combination of high-temperature strength and resistance to chemical degradation, making it a preferred option for critical industrial infrastructure.
Key Characteristics
Material Type: Chromoly (Chromium-Molybdenum) alloy steel.
Primary Use: Weldable pressure vessels and boilers for elevated temperature service.
Industries: Oil & Gas, Chemical Processing, Power Generation.
Key Properties: High strength, good weldability, excellent resistance to creep, corrosion, and oxidation, good low-temperature toughness.
Composition (Typical)
Chromium (Cr): 2.00% - 2.50%
Molybdenum (Mo): 0.90% - 1.10%
Carbon (C): 0.05% - 0.15%
Application: Elevated temperature service in pressure vessels, boilers, heat exchangers, etc..
What is ASTM A387 Grade 22 Class 2 equivalent to?
ASTM A387 Grade 22 Class 2 is a chromium-molybdenum alloy steel for high-temperature service, with key equivalents being ASME SA387 Grade 22 Class 2, EN 10CrMo9-10, and DIN 10CrMo9-10, along with British standard BS 622-515B. These standards denote similar chemical compositions and mechanical properties for pressure vessel applications requiring elevated temperatures.
What are Common Testing Requirements ASTM A387 Grade 22 Class 2 ?
ASTM A387 Grade 22 Class 2 requires specific mechanical properties, primarily Tensile Strength (75-100 ksi / 515-690 MPa) and minimum Yield Strength (45 ksi / 310 MPa), with 18% minimum elongation in 2 inches (50mm) and 40-45% reduction of area, alongside detailed chemical composition (Chromium ~2-2.5%, Molybdenum ~1%) and heat treatment (normalized/quenched & tempered), ensuring suitability for pressure vessels through mechanical tests like tensile, impact, and ultrasonic testing.
What is the hardness of ASTM A387 Grade 22 Class 2 ?
For ASTM A387 Grade 22 Class 2, the Brinell hardness (HB) typically falls within the range of 150 to 180 HB, although some sources mention a slightly broader or different range like 130-170 HB, with the hardness being a result of its specific heat treatment and chemical composition (2.25% Cr, 1% Mo), providing higher strength than Class 1.
Equivalents
| BS | EN | ASTM/ASME | DIN |
|---|---|---|---|
| 622-515B | 10CrMo910 | A/SA387-22-2 | 10CrMo910 |
Dimension Range
|
Grade |
Product type |
Thickness |
Width |
Length |
|---|---|---|---|---|
|
Grade 22 |
Plate |
4.70 - 91.4 |
1500 - 3350 |
1900 - 15000 |
Chemical Requirements
| C | Mn | P | S | Si | Cr | Mo | V |
|---|---|---|---|---|---|---|---|
| 0.05 – 0.15 | 0.30 – 0.60 | 0.025 | 0.025 | 0.50 | 2.00 – 2.50 | 0.90 – 1.10 | – |
Tensile Requirements for Class 2 Plates
| Designation | Requirement | Grade 22 |
|---|---|---|
| A387 Grade 22 | Tensile strength, ksi [MPA] | 75 to 100 [515 to 690] |
| Yield strength, min, ksi [MPa]/(0.2% offset) | 45 [310] | |
| Elongation in 8 in. [200mm], min % | ||
| Elongation in 2 in. [50mm], min, % | 18 | |
| Reduction of area, min % | 45 (measured on round specimen) 40 (measured on flat specimen) |
1What is the P number of ASTM A387 Grade 22 Class 2?
The P-number for ASTM A387 Grade 22 Class 2 chromium-molybdenum steel is P5, as it falls within the 5% to 9% Chromium-Molybdenum steels group, used in pressure vessels and boilers, similar to other P5 materials like SA-182 F5 or SA-213 T5.
2What are the primary advantages of ASTM A387 Grade 22 Class 2?
ASTM A387 Grade 22 Class 2's primary advantages are its excellent high-temperature performance, superior oxidation/corrosion resistance (due to chromium & molybdenum), and good mechanical strength, making it ideal for welded boilers and pressure vessels in demanding oil, gas, and chemical service where heat and corrosive environments are common. Its key benefits include durability, weldability, and reliability at elevated temperatures, preventing issues like creep.
3What temperature is ASTM A387 Grade 22 Class 2 ?
ASTM A387 Grade 22 Class 2 is designed for high-temperature service, maintaining strength up to around 600°C (1112°F), with its tempering heat treatment often occurring around 675°C (1250°F) to provide good high-temperature creep resistance and low-temperature toughness for boilers, pressure vessels, and heat exchangers. Its chromium (2.25%) and molybdenum (1%) content enhance high-temperature strength and corrosion resistance, making it excellent for refining and chemical plants.
4What are the typical application fields of ASTM A387 Grade 22 Class 2?
ASTM A387 Grade 22 Class 2 is a chromium-molybdenum alloy steel primarily used for high-temperature and high-pressure applications, especially in pressure vessels, boilers, and heat exchangers within the oil & gas, petrochemical, and power generation industries. Its excellent resistance to oxidation, creep, and corrosion at elevated temperatures makes it ideal for critical components like reactor vessels, piping, distillation columns, and high-pressure steam systems, where it maintains structural integrity under extreme stress and thermal cycling.
5What welding rod for ASTM A387 Grade 22 Class 2 ?
For welding ASTM A387 Grade 22 Class 2 (a 2.25Cr-1Mo steel for high-temperature service), use matching or compatible chromium-molybdenum electrodes like E9015-B3, E9018-B3, or matching filler metals (e.g., ER90S-B3 for GMAW), often requiring preheat, interpass temperature control, and Post Weld Heat Treatment (PWHT) to prevent cracking and temper embrittlement, especially in high-temperature applications.
6What precautions should be taken when welding ASTM A387 Grade 22 Class 2?
When welding ASTM A387 Grade 22 Class 2 (a Cr-Mo steel), key precautions involve strict control of heat input, using low-hydrogen filler metals, implementing preheating to reduce cooling rates, controlling interpass temperatures, and performing post-weld heat treatment (PWHT) to prevent hydrogen cracking and maintain mechanical properties, alongside standard welding safety like proper PPE and ventilation.
7How heavy is ASTM A387 Grade 22 Class 2 steel?
ASTM A387 Grade 22 Class 2 steel's "heaviness" (density) is about 7.9 g/cm³ (490 lb/ft³), but its weight depends on its dimensions (thickness, length, width); for example, a 1-inch thick plate weighs approximately 40.8 lbs per square foot, while a 3/4-inch plate is about 30.6 lbs/ft², as it's a chromium-molybdenum alloy used for pressure vessels with specific mechanical properties, not a fixed weight.
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