ASTM A387 Grade 22 Class 1 is a chromium-molybdenum alloy steel plate designed for use in welded pressure vessels and high-temperature service. It belongs to the family of heat-resistant alloy steels known for their good creep strength and resistance to hydrogen attack at elevated temperatures. Class 1 designation indicates a higher level of toughness requirement compared to Class 2, with more stringent impact testing criteria to ensure reliable performance under demanding conditions.
Equivalents for ASTM A387 Grade 22 Alloy Steel Plates
| BS | EN | ASTM/ASME | DIN |
| 622-515B | 10 CRMO910 | A387-22-1 | 10 CRMO910 |
Specifications for ASTM A387 Grade 22 Alloy Steel Plates
| Designation | Nominal Chromium Content (%) |
Nominal Molybdenum Content (%) |
| A387 Grade 22 | 2.25% | 1.00% |
Tensile Requirements for ASTM A387 Grade 22 Alloy Steel Plates Class 1 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) |
Chemical Requirements for ASTM A387 Grade 22 Alloy Steel Plates
| Element | Chemical Composition (%) | |
| A387 Grade 22 | ||
| Carbon: | Heat Analysis: | 0.05 - 0.15 |
| Product Analysis: | 0.04 - 0.15 | |
| Manganese: | Heat Analysis: | 0.30 - 0.60 |
| Product Analysis: | 0.25 - 0.66 | |
| Phosphorus: | Heat Analysis: | 0.035 |
| Product Analysis: | 0.035 | |
| Sulphur (max): | Heat Analysis: | 0.035 |
| Product Analysis: | 0.035 | |
| Silicon: | Heat Analysis: | 0.50 max |
| Product Analysis: | 0.50 max | |
| Chromium: | Heat Analysis: | 2.00 - 2.50 |
| Product Analysis: | 1.88 - 2.62 | |
| Molybdenum: | Heat Analysis: | 0.90 - 1.10 |
| Product Analysis: | 0.85 - 1.15 |
Core Advantages
High-Temperature Creep Resistance:
The addition of molybdenum significantly enhances the steel's tensile strength and creep resistance. It can maintain structural integrity at constant operating temperatures up to 600°C (1112°F), preventing slow deformation under long-term thermal stress.
Oxidation and Corrosion Protection:
The high chromium content provides a robust protective layer against oxidation and scaling. This makes the alloy highly durable in environments where standard carbon steel would rapidly degrade due to heat-induced rust.
Hydrogen and Sour Gas Resistance:
This grade is specifically designed to resist Hydrogen Induced Cracking (HIC) and sulfide stress corrosion. It is the gold standard for "sour service" applications involving hydrogen sulfide (H2S)
Excellent Fabricability:
Despite its strength, Class 1 provides a lower tensile range (515–690 MPa) compared to Class 2, offering better ductility. This makes it easier to cold-bend, cut, and weld during the manufacturing of complex vessel geometries.
Primary Applications
Petrochemical & Refining:
It is the primary material for hydrocracking reactors, catalytic reformers, and coke drums, where high pressure and high temperatures are constant.
Power Generation:
Used extensively in fossil fuel and nuclear power plants for boiler drums, superheater tubes, and high-pressure steam piping.
Oil & Gas Processing:
Essential for separation vessels and heat exchangers that process raw crude oil and natural gas containing corrosive contaminants.
Chemical Manufacturing:
Utilized in the fabrication of reaction vessels that handle volatile chemical syntheses at extreme temperatures.
Why Choose Us :
You can get the perfect material according to your requirement at the least possible price.
We also offer Reworks, FOB, CFR, CIF, and door to door delivery prices. We suggest you to do deal for shipping which will be quite economical.
The materials we provide are completely verifiable, right from raw material test certificate to the final dimensional statement.(Reports will show on requirement)
We guarantee to give a response within 24hours(usually in the same hour)
You can get stock alternatives, mill deliveries with minimizing manufacturing time.
We are fully dedicated to our customers. If it will not possible to meet your requirements after examining all options, we will not mislead you by making false promises which will create good customer relations.
If you have project requirements for ASTM A387 Grade 22 Class 1, we welcome your inquiry. GNEE maintains a large inventory of commonly used high strength steel grades for your selection.For detailed mechanical properties, chemical composition, and technical data, as well as free samples, please contact our factory immediately. We offer competitive prices, stable quality, and professional service. Email:beam@gneesteelgroup.com.
Can A387 Grade 22 Class 1 be cold-formed?
It can be cold-formed with caution, but preheating is recommended for thick plates to avoid cracking. Post-forming heat treatment is needed to restore mechanical properties and eliminate residual stress.
What is the thermal conductivity of A387 Grade 22 Class 1?
At room temperature, its thermal conductivity is about 42 W/(m·K), decreasing slightly with increasing temperature. This property ensures efficient heat transfer in heat exchanger applications.
How does A387 Grade 22 Class 1 differ from A36 steel?
A36 is carbon steel with low strength at high temperatures. Grade 22, as Cr-Mo alloy steel, has excellent high-temperature creep resistance and is for pressure vessels, while A36 is for general structural use.
What is the difference between A387 Grade 22 Class 1 and A387 Grade 9 Class 1?
Grade 9 has 9% Cr and 1% Mo, offering better oxidation resistance at higher temps. Grade 22 is more cost-effective for 400-550°C, while Grade 9 is suitable for temperatures above 600°C.
What is the density of A387 Grade 22 Class 1?
Its density is approximately 7.85 g/cm³, the same as ordinary carbon steel. This makes it easy to calculate weight in engineering design, without additional load concerns.
What is the hardness limit of A387 Grade 22 Class 1 after heat treatment?
After proper heat treatment, its Brinell hardness (HB) is typically ≤207. Excessive hardness indicates incomplete tempering, which may reduce toughness and increase brittleness risk.
What is the difference between A387 Grade 22 Class 1 and AISI 4130?
AISI 4130 is a low-alloy steel for structural use, with lower Cr-Mo content. Grade 22 has higher high-temperature resistance and is designed for pressure vessels, while 4130 is for mechanical parts.
How does A387 Grade 22 Class 1 perform vs. A387 Grade 5 Class 1?
Grade 5 has 0.5% Mo without Cr, so Grade 22 has superior oxidation and sulfidation resistance. Grade 22 is better for high-temperature, corrosive environments, while Grade 5 is for milder conditions.
What is the contrast between A387 Grade 22 Class 1 and A240 304?
304 has better corrosion resistance but lower high-temperature strength and higher cost. Grade 22 excels in high-temperature pressure-bearing scenarios, while 304 is for general corrosive environments.
How does A387 Grade 22 Class 1 perform vs. A480 430 stainless steel?
430 is ferritic stainless steel with 17% Cr, better corrosion resistance but poorer creep strength. Grade 22 is designed for high-temperature pressure vessels, while 430 is for decorative or mild corrosive parts.