what is astm a387 grade 22 class 2 chemical composition
ASTM A387 Grade 22 Class 2 is a chromium-molybdenum alloy steel for pressure vessels, with key compositions including 2.00-2.50% Chromium (Cr) and 0.90-1.10% Molybdenum (Mo), plus controlled amounts of Carbon (C), Manganese (Mn), Silicon (Si), Phosphorus (P), and Sulfur (S), offering high strength and corrosion resistance at elevated temperatures.
ASTM A387 Grade 22 (ASME SA387 Grade 22) is a chromium-molybdenum alloy steel plate used for making boilers and pressure vessels designed for high-temperature and high-pressure service. The material features a chromium content of 2.00% to 2.50% and a molybdenum content of 0.90% to 1.10%. The higher chromium content provides superior corrosion and oxidation resistance, making it suitable for storing oil, gas, or other liquids and ensuring compatibility with sour services.
ASTM A387 Grade 22 Class 2 plates are designed to perform continuously at varying temperatures and can operate effectively at temperatures up to 600°C. The inclusion of molybdenum increases both the temperature resistance and the tensile strength of the alloy. Furthermore, the lattice strain within the material provides amazing oxidation and corrosion resistance, serving as an excellent choice for heat resistance by preventing interference from iron-based corrosive mediators.
Characterized by good weldability and durability, Alloy 387 is specifically engineered to meet high-performance industrial standards. ASTM A387 GR 22 CL 2 plates are impeccable for applications requiring ideal durability, leak-proof integrity, and easy installation. These qualities make the alloy a preferred choice for precision design and critical fabrications in demanding thermal environments.
Key Characteristics:
Material Type: Chrome Moly (Chromium-Molybdenum) Alloy Steel.
Primary Use: Welded pressure vessels and boilers for elevated temperature service (up to ~600°C).
Composition: Approximately 2.25% Chromium (Cr) and 1% Molybdenum (Mo).
Benefits: Excellent heat resistance, anti-corrosion, and oxidation resistance; improved tensile strength at high temperatures due to molybdenum.
Applications:
Oil & Gas industry equipment.
Chemical processing plants.
Power generation equipment.
Heat exchangers.
ASTM A387 GR 22 CLASS 2 Plate Specification
Grade : ASTM A387 Gr 22 CL.2 Alloy Steel Plates
Standard : ASTM A387 / ASME SA387
Width : 1000mm-4500mm
Thickness : 5mm-150mm
Length : 3000mm -18000mm
Impact tested : -52° C
What 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 pressure vessels, boilers, heat exchangers, and piping in high-temperature, high-pressure applications, especially in the oil & gas, petrochemical, chemical processing, and power generation industries, due to its excellent heat resistance, strength, and corrosion/oxidation resistance.
What is ASTM A387 Grade 22 Class 2 equivalent to?
ASTM A387 Grade 22 Class 2 is equivalent to ASME SA387-22-2, and internationally corresponds to EN 10CrMo9-10 (or 10CrMo910), DIN 10CrMo9-10, and BS 622-515B, all being chromium-molybdenum alloy steels for high-temperature pressure vessels. Other national equivalents include Poland's PN 10H2M, Czechia's CSN 15313, Austria's ONORM 10CrMo9-10KW, and Kazakhstan's GOST 10KH2M.
What precautions should be taken when welding ASTM A387 Grade 22 Class 2 ?
When welding ASTM A387 Grade 22 Class 2, focus on hydrogen control (low-hydrogen consumables, bake electrodes), preheating (to ~150°C-200°C for thick sections), controlled interpass temperatures, using stringer beads (no weaving), and mandatory Post-Weld Heat Treatment (PWHT) (around 700-760°C) to prevent hydrogen-induced cracking (HIC) and temper embrittlement, alongside standard safety like ventilation and PPE.
Equivalents
| BS | EN | ASTM/ASME | DIN |
|---|---|---|---|
| 622-515B | 10CrMo910 | A/SA387-22-2 | 10CrMo910 |
Chromium & Molybdenum content (according to the ASTM specification):
| Designation | Nominal Chromium Content (%) | Nominal Molybdenum Content (%) |
|---|---|---|
| A387 Grade 22 | 2.25% | 1.00% |
ASTM A387 GR 22 CLASS 2 Chemical Composition
| Grade | C | Mn | P | S | Si | Cr | Mo |
| A387 Gr.22 | 0.05-0.15 | 0.30-0.60 | 0.035 | 0.035 | 0.50 max | 2.00-2.50 | 0.90-1.10 |
Tensile Requirements for ASTM A387 Grade 22 Alloy Steel Plates 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) |
1. What is the difference between ASTM A387 Grade 22 Class 2 and ASTM A387 Grade 22 Class 1?
The main difference between ASTM A387 Grade 22 Class 1 and Class 2 is mechanical strength, with Class 2 offering significantly higher tensile and yield strength for more demanding high-temperature, high-pressure applications, while both share the same chemical composition (2.25% Chromium, 1.00% Molybdenum). Class 2 provides enhanced toughness, making it suitable for critical pressure vessels, whereas Class 1 offers better weldability and formability for standard service.
2. Is ASTM A387 Grade 22 Class 2 carbon steel?
No, ASTM A387 Grade 22 Class 2 is chromium-molybdenum alloy steel, not plain carbon steel; it's a low alloy steel with significant additions of chromium (around 2.25%) and molybdenum (around 1%) for enhanced high-temperature strength and corrosion resistance, making it ideal for boilers and pressure vessels. While it contains carbon (0.05-0.15%), the defining feature is the alloying elements that give it superior properties for elevated-temperature service.
3. What is ASTM A387 Grade 22 Class 2 high speed steel?
ASTM A387 Grade 22 Class 2 is a chromium-molybdenum alloy steel plate designed for high-temperature applications, primarily in welded boilers and pressure vessels for the oil, gas, and petrochemical industries, offering superior strength, creep resistance, and corrosion/oxidation resistance compared to Class 1, with specific mechanical properties requiring normalization and tempering for enhanced performance.
4. What is the P number of ASTM A387 Grade 22 Class 2 ?
For ASTM A387 Grade 22 Class 2, the material falls under P-Number 5B in the ASME Section IX welding code, identifying it as a Chromium-Molybdenum alloy steel, which is grouped with other similar low-alloy steels for welding procedure qualification.
5. What is ASTM A387 Grade 22 Class 2 material ?
ASTM A387 Grade 22 Class 2 is a chromium-molybdenum (Cr-Mo) alloy steel plate designed for welded boilers and pressure vessels in elevated temperature service, offering excellent high-temperature strength, corrosion resistance, and weldability, commonly used in the oil, gas, and chemical industries for equipment like heat exchangers and pipelines. The "Grade 22" signifies its ~2% Chromium and ~1% Molybdenum content, while "Class 2" denotes specific mechanical properties, including higher tensile strength requirements (75-100 ksi).
6. What temperature is ASTM A387 Grade 22 Class 2 ?
ASTM A387 Grade 22 Class 2 is a chromium-molybdenum alloy steel designed for high-temperature service, typically up to around 600°C (1112°F), offering excellent strength, durability, and resistance to oxidation and creep in applications like pressure vessels, boilers, and heat exchangers, with specific mechanical properties verified by impact testing at lower temperatures like -30°C.
7. How heavy is ASTM A387 Grade 22 Class 2?
ASTM A387 Grade 22 Class 2 isn't a specific weight but a type of chromium-molybdenum alloy steel plate with defined mechanical properties, meaning its weight depends on its dimensions (thickness, width, length), but its density is around 7.9 g/cm³ (490 lb/ft³), allowing you to calculate its weight based on size, featuring high strength (75-100 ksi tensile) for elevated temperature pressure vessel applications.
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