Is ASTM A387 Grade 22 Class 1 carbon steel?
No, ASTM A387 Grade 22 Class 1 is not plain carbon steel; it's a chromium-molybdenum (Cr-Mo) alloy steel, specifically designed as a pressure vessel plate for elevated temperature service, offering better heat resistance and corrosion properties than standard carbon steels due to its ~2.25% Chromium and ~1.00% Molybdenum content. While it's related to carbon steel (as it's a steel), the added alloying elements classify it as an alloy steel for high-temperature, high-pressure applications in industries like oil, gas, and petrochemicals, unlike basic carbon steels.
ASTM A387 Grade 22 Class 1 is a specialized chromium-molybdenum alloy steel plate designed primarily for use in welded boilers and pressure vessels operating at elevated temperatures. The "Grade 22" designation refers to its specific chemical composition, which contains approximately 2.25% Chromium and 1.00% Molybdenum. These elements are critical for industrial performance: chromium provides excellent resistance to oxidation and corrosion (particularly in sour gas environments), while molybdenum enhances the material's strength and creep resistance, allowing it to maintain structural integrity under long-term thermal stress in the oil, gas, and petrochemical sectors.
The "Class 1" designation specifically identifies the mechanical properties and heat treatment of the steel, distinguishing it from the higher-strength Class 2. Class 1 is typically supplied in the annealed condition, which results in a lower tensile strength range-specified between 415 and 585 MPa (60 to 85 ksi)-and a minimum yield strength of 205 MPa (30 ksi). This specific classification offers greater ductility and ease of fabrication compared to Class 2, making it a steadfast solution for complex pressure vessel components like heat exchangers and reactors that must withstand extreme thermal conditions without becoming brittle.
Key Characteristics
Material Type: Chromium-Molybdenum (Cr-Mo) alloy steel.
Application: Primarily for pressure vessels and boilers used at elevated temperatures.
Alloying Elements: Contains about 2.25% Chromium and 1.00% Molybdenum, which enhance high-temperature strength and corrosion resistance.
Class: "Class 1" refers to a specific lower tensile strength range compared to Class 2.
Condition: Often supplied in the annealed (stress-relieved) condition for improved ductility.
Industry Use: Suited for demanding environments in the oil, gas, and petrochemical sectors due to its resistance to sour gas and high temperatures.
A387 Grade 22 Class 2 (For Comparison)
Tensile Strength: Higher, at 75-100 ksi (515-690 MPa).
Yield Strength: Higher, at around 45 ksi (310 MPa).
What welding rod for ASTM A387 Grade 22 Class 1?
For welding ASTM A387 Grade 22 Class 1 (2.25Cr-1Mo steel), you typically use matching low-alloy steel consumables like E/ER70S-2 for GTAW/SMAW or E7018 for SMAW, often with preheat and post-weld heat treatment (PWHT) to prevent cracking, but for demanding applications, nickel-based electrodes (like ENiCrMo-3/ERNiCrMo-3) are used to avoid carbide formation and carbon migration, notes weldermetals.com, adorswelding.com, and shew-esteelpipe.com/news/welding-analysis-of-cr-mo-steel-and-stainless-23639457.html. Key considerations are the 2.25% Cr and 1% Mo content, requiring filler metals that match or exceed these elements for service at elevated temperatures, often requiring PWHT, and potentially nickel-based fillers for dissimilar joints or to mitigate issues like temper embrittlement,
What temperature is ASTM A387 Grade 22 Class 1 ?
ASTM A387 Grade 22 Class 1 is designed for high-temperature service, with its minimum tempering temperature being 1250°F (675°C), and it performs well in applications up to around 600°C (1112°F), offering excellent strength and corrosion resistance in elevated temperature environments like boilers and pressure vessels.
What are the typical application fields of ASTM A387 Grade 22 Class 1 ?
ASTM A387 Grade 22 Class 1 is a chrome-moly alloy steel primarily used for high-temperature pressure vessels, boilers, and heat exchangers, serving the oil, gas, petrochemical, and power generation industries due to its excellent resistance to heat, oxidation, and corrosion, especially in demanding environments like refineries. It's ideal for components such as flanges, ducting, and pressure vessels operating under elevated temperatures, with a working range up to about 600°C (1100°F).
Equivalents for ASTM A387 Grade 22 Alloy Steel Plates
| BS | EN | ASTM/ASME | DIN |
| 622-515B | 10 CRMO910 | A387-22-1 | 10 CRMO910 |
ASTM A387 GR 22 CLASS 1Plate Specification :
| Standard | ASTM A387 / ASME SA 387 |
|---|---|
| Width | 1000mm-4500mm |
| Thickness | 5mm-150mm |
| Length | 3000mm-18000mm |
| Impact tested | -52° C |
| Material | Alloy Steel |
| Process of Manufacturing | Hot-Rolled (HR) |
Alloy Steel ASTM A387 GR 22 CL. 1 / 2 Plates Chemical Composition :
| Grade | C | Mn | P | S | Si | Cr | Mo |
| Alloy Steel Gr.22 | 0.04 – 0.15 | 0.25 – 0.66 | 0.035 | 0.035 | 0.5 max | 1.88 – 2.62 | 0.85 – 1.15 |
Alloy steel ASTM A387 GR. 22 CL. 1 Plates Mechanical Properties :
| ASTM A387 Grade 22 | Tensile Strength (ksi) | Tensile Strength (MPa) | Yield Strength (ksi) | Yield Strength (MPa) | Elongation in 200mm (%) | Elongation in 50mm (%) | Reduction of area in % |
| Class 1 | 60-85 | 415-585 | 30 | 205 | – | 18 | 45 |
Specifications for ASTM A387 Grade 22 Alloy Steel Plates
| Designation | Nominal Chromium Content (%) |
Nominal Molybdenum Content (%) |
| A387 Grade 22 | 2.25% | 1.00% |
1. What is the composition of ASTM A387 Grade 22 Class 1 ?
ASTM A387 Grade 22 Class 1 is a chromium-molybdenum alloy steel for pressure vessels, primarily containing around 2.25% Chromium (Cr) and 1.00% Molybdenum (Mo), with specified limits for Carbon (C), Manganese (Mn), Phosphorus (P), Sulfur (S), and Silicon (Si) to ensure high-temperature strength and corrosion resistance, particularly suitable for welded boiler and pressure vessel service.
2. What is ASTM A387 Grade 22 Class 1 material ?
ASTM A387 Grade 22 Class 1 is a chromium-molybdenum alloy steel plate designed for welded boilers and high-temperature pressure vessels, featuring around 2.25% Chromium and 1% Molybdenum, offering good strength and corrosion resistance, with Class 1 indicating a specific, lower tensile strength range compared to Class 2.
3. What is ASTM A387 Grade 22 Class 1 high speed steel?
ASTM A387 Grade 22 Class 1 is a chromium-molybdenum alloy steel plate designed for high-temperature pressure vessels and boilers, offering good corrosion resistance, with specific mechanical properties like lower yield/tensile strength than Class 2, and requiring normalization
4. What is the hardness of ASTM A387 Grade 22 Class 1 ?
ASTM A387 Grade 22 Class 1 steel typically has a Brinell hardness of around 190 HBW, though specific hardness can vary slightly with heat treatment, but it's usually within a range corresponding to its tensile properties, with common values around 415-585 MPa tensile strength and minimum yield strength around 205-240 MPa.
5. What is ASTM A387 Grade 22 Class 1 equivalent to?
ASTM A387 Grade 22 Class 1 is equivalent to ASME SA387 Grade 22 Class 1, and internationally to standards like EN 10 CRMO 9-10, DIN 10CrMo9-10, and BS 622-515B, all specifying a 2.25% Chromium, 1% Molybdenum alloy steel for high-temperature pressure vessels, with Class 1 indicating lower tensile strength than Class 2.
6. What precautions should be taken when welding ASTM A387 Grade 22 Class 1 ?
When welding ASTM A387 Grade 22 Class 1, key precautions involve thorough surface cleaning, implementing preheating and post-weld heat treatment (PWHT) to prevent cracking (especially stress relief at ~690°C), using low-hydrogen consumables, ensuring proper ventilation, and wearing full Personal Protective Equipment (PPE) like a helmet, gloves, and flame-retardant clothing to manage risks from fumes, radiation, and spatter. This low-alloy Cr-Mo steel is prone to cold cracking due to its hardenability, necessitating careful control of heat input and residual stress.
7. Is ASTM A387 Grade 22 Class 1 carbon steel?
No, ASTM A387 Grade 22 Class 1 is not plain carbon steel; it's a chromium-molybdenum (Cr-Mo) alloy steel, specifically designed as a pressure vessel plate for elevated temperature service, offering better heat resistance and corrosion properties than standard carbon steels due to its ~2.25% Chromium and ~1.00% Molybdenum content. While it's related to carbon steel (as it's a steel), the added alloying elements classify it as an alloy steel for high-temperature, high-pressure applications in industries like oil, gas, and petrochemicals, unlike basic carbon steels
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