ASTM A387 Grade 22 Class 2 is a chromium-molybdenum (Cr-Mo) alloy steel plate for high-temperature, high-pressure applications like boilers and pressure vessels, offering superior toughness (Class 2) and excellent corrosion/oxidation resistance, common in oil, gas, and chemical industries for reactors, heat exchangers, and piping. It's always supplied normalized and tempered, ensuring strength at elevated temperatures and good low-temperature impact toughness, with specific chemical compositions .
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 |
Mechanical Property
|
A387 Gr.22 CL.2 Mechanical Property |
||||
|
Thickness |
Yield |
Tensile |
Elongation |
|
|
A387 Gr.22 Cl.2 |
mm |
Min Mpa |
Mpa |
Min % |
|
t≦50 |
310 |
515-690 |
18 |
|
|
50<t≦200 |
- |
- |
- |
|
Applications
Oil & Gas: Pressure vessels, piping, and equipment in refineries and sour service (H2S environments).
Petrochemical Industry: Reactors, piping, and vessels in chemical processing plants.
Power Generation: Boilers, heat recovery steam generators (HRSG), turbines, and high-temperature ducting.
Other: Heat exchangers, pressure vessels, and structural components in demanding environments.
Advantages
High Temperature Performance: Designed for elevated temperatures, preventing creep and maintaining strength.
Corrosion & Oxidation Resistance: Chromium and molybdenum content provide superior resistance to oxidation and corrosive media, including sour gas.
Superior Strength: Higher tensile and yield strength compared to plain carbon steels, suitable for high-stress applications.
Good Weldability: Can be readily welded, crucial for fabricating complex pressure vessels.
Versatility: Available in various thicknesses and forms, meeting stringent industry standards.
Request a professional quotation for ASTM A387 Grade 22 Class 2 from GNEE Steel.
What is the core difference between ASTM A387 Grade 22 Class 2 and Class 1?
The core difference between the two lies in mechanical property requirements and heat treatment processes. Class 2 requires higher tensile strength, yield strength, and impact toughness, and is usually subjected to normalizing + tempering heat treatment to ensure the structural stability of the material under high temperature and pressure conditions. In contrast, Class 1 has relatively lower mechanical property indicators, and its heat treatment process can be adjusted according to actual needs, with application scenarios that are less severe than those of Class 2.
What type of steel is ASTM A387 Grade 22 Class 2, and what are its core alloying components?
ASTM A387 Grade 22 Class 2 is a chromium-molybdenum alloy heat-resistant steel plate, belonging to the category of low-alloy high-strength steel. Its core alloying components include approximately 2.25% chromium (Cr) and 1.0% molybdenum (Mo), supplemented by basic elements such as carbon, manganese, and silicon. The alloy ratio endows it with excellent high-temperature mechanical properties and corrosion resistance.