What is ASME SA387 Gr.22 heat resistant alloy steel plate?
ASME SA387 Grade 22 heat resistant alloy steel plate is a 2.25Cr-1Mo chromium-molybdenum pressure vessel steel manufactured in accordance with the ASME SA387/ASTM A387 specification, making it ideal for elevated-temperature welded pressure vessels. Designed specifically for long-term service under elevated temperatures and high pressures, this steel plate exhibits exceptional elevated-temperature strength, creep resistance, oxidation resistance, and weldability, making it one of the most widely used Cr-Mo steels in the petroleum refining, petrochemical, and power generation industries.
Compared with conventional carbon steel plates, our SA387 Gr. 22 offers superior mechanical stability at elevated temperatures. It is commonly utilized in equipment operating within a temperature range of 450°C to 600°C, where creep resistance is a critical design requirement. The addition of 2.25% Chromium enhances its resistance to oxidation and corrosion, while the 1.0% Molybdenum addition boosts its elevated-temperature strength and long-term creep-rupture resistance.
As an experienced pressure vessel steel plate supplier, GNEE Steel provides SA387 Grade 22 plates with full material traceability, custom fabrication, and third-party inspection (TPI) support, assisting clients in meeting the stringent ASME fabrication and quality requirements for elevated-temperature pressure vessel projects.
Performance Advantages of ASME SA387 Gr.22 heat resistant alloy steel plate
Excellent Elevated-Temperature Strength
ASME SA387 Gr. 22 is a 2.25Cr-1Mo alloy steel designed for pressure vessels operating at 450–600°C. With a minimum yield strength of 310 MPa and a tensile strength of 585–760 MPa, Grade 22 Class 2 provides reliable strength retention and structural stability during long-term, elevated-temperature service.
Superior Long-Term Creep Resistance
Upon normalizing and tempering, SA387 Gr. 22 steel develops a stable tempered bainitic or bainitic-ferritic matrix, which enhances its long-term creep resistance. It is widely utilized in elevated-temperature pressure equipment designed for a service life of up to 100,000 hours, extending equipment life expectancy and boosting reliability.
Outstanding Resistance to High-Temperature Hydrogen Attack (HTHA)
The 2.25Cr-1Mo alloy system offers significantly better resistance to high-temperature hydrogen attack (HTHA) compared to conventional carbon steels. For hydrogen service applications, SA387 Gr. 22 is standardly selected in accordance with API RP 941 (Nelson Curves) and is extensively used in hydrotreating reactors and high-pressure separators.
Excellent Weldability for Pressure Vessel Fabrication
SA387 Gr. 22 steel exhibits good weldability when proper welding procedures are followed. Preheating (typically at 150–200°C) and Post-Weld Heat Treatment (PWHT) are standardly recommended to mitigate the risk of delayed hydrogen cracking and ensure the long-term integrity of the welded joints.
Superb Formability and Fabrication Capabilities
SA387 Gr. 22 steel can be processed using CNC cutting, rolling, hot forming, cold forming, flanging, and dishing, making it ideal for fabricating complex pressure vessel components. GNEE also offers customized cutting, beveling, ultrasonic testing (UT), and machining services to optimize fabrication efficiency and shorten project schedules.
Selecting the appropriate chromium-molybdenum (Cr-Mo) steel grade during the design phase can significantly reduce lifecycle maintenance costs and enhance equipment reliability. Our engineering team assists clients in evaluating operating temperatures, hydrogen partial pressures, and applicable design codes to recommend the most suitable material selection prior to procurement.
ASME SA387 Gr.22 heat resistant alloy steel plate Specification
| Item | Specification |
|---|---|
| Product Name | ASME SA387 Gr.22 Heat Resistant Alloy Steel Plate |
| Material Type | Chromium-Molybdenum (Cr-Mo) Alloy Steel Plate |
| Steel Grade | Grade 22 Class 1 / Grade 22 Class 2 |
| Alloy Composition | 2.25% Chromium (Cr), 1.0% Molybdenum (Mo) |
| Standard | ASME SA387 / ASTM A387 |
| Thickness Range | 6–300 mm |
| Width Range | 1,500–4,000 mm |
| Length Range | 3,000–18,000 mm |
| Certification | EN 10204 Type 3.1 / 3.2, Mill Test Certificate (MTC) |
| Third-Party Inspection | SGS, TÜV, BV, LR, DNV, ABS |
| Processing Services | CNC Cutting, Beveling, Drilling, Rolling, Flame Cutting, Edge Preparation |
| Packaging | Export Seaworthy Packing with Steel Strapping and Moisture Protection |
ASME SA387 Gr.22 heat resistant alloy steel plate Chemical Composition
| Element Composition % | ||
|---|---|---|
| SA 387 Grade 22 |
||
| Carbon, max: | ||
| Heat analysis | 0.05-0.15A | |
| Product analysis | 0.04-0.15A | |
| Manganese, max: | ||
| Heat analysis | 0.30-0.60 | |
| Product analysis | 0.25-0.66 | |
| Phosphorus, max: | ||
| Heat analysis | 0.025 | |
| Product analysis | 0.025 | |
| Sulfur, max: | ||
| Heat analysis | 0.025 | |
| Product analysis | 0.025 | |
| 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 | |
Note: Heat Analysis represents the chemical composition determined by ladle sampling during the steelmaking stage, whereas Product Analysis represents the permissible variations checked on samples taken from the finished steel plate-the latter typically exhibiting wider tolerances than the former due to factors such as segregation.
ASME SA387 Gr.22 heat resistant alloy steel plate Mechanical Property
|
Grade |
Thickness |
Yield strength |
Tensile strength |
Elongation in 2" 1) |
Reduction of area 2) |
|---|---|---|---|---|---|
|
Grade 22 Class 1 |
0.185 - 3.60 |
30 |
60 - 85 |
18 |
40 |
|
Grade 22 Class 2 |
0.185 - 3.60 |
45 |
75 - 100 |
18 |
40 |
Heat Treatment and Elevated-Temperature Properties of ASME SA387 Gr.22
Normalizing and Tempering (N+T)
Our ASME SA387 Gr. 22 Class 2 plates are standardly supplied in the Normalized and Tempered (N+T) condition. This thermal processing refines the grain structure and develops a stable matrix of tempered bainite and ferrite, ensuring a minimum yield strength of 310 MPa and a tensile strength of 585–760 MPa, while concurrently enhancing toughness and long-term creep resistance.
Annealed Condition
Our ASME SA387 Grade 22 Class 1 steel is typically supplied in the Annealed condition, which provides lower strength but superior workability and formability for less demanding applications. It is frequently utilized where high elevated-temperature creep strength is not a primary requirement.
Post-Weld Heat Treatment (PWHT)
Due to the 2.25% Chromium and 1.0% Molybdenum content in SA387 Gr. 22 steel, post-weld heat treatment (PWHT) is standardly performed after welding to relieve residual stresses, temper the heat-affected zone (HAZ), and mitigate the risk of delayed hydrogen cracking.
Exceptional Thermal Resistance
The Cr-Mo alloy system enables ASME SA387 Gr. 22 to maintain stable mechanical properties during long-term service at 450–600°C. Chromium enhances resistance to oxidation and scaling, while molybdenum boosts creep strength, making this material highly suitable for reactors, heat exchangers, steam drums, and other high-temperature, high-pressure equipment.
Every SA387 Grade 22 plate supplied by GNEE can be delivered in the required heat-treated condition with complete furnace records, heat treatment charts, and EN 10204 Type 3.1 certification, ensuring full traceability for pressure vessel fabrication projects.
ASME SA387 Gr.22 heat resistant alloy steel plate Typical Applications
Petrochemical Industry
SA387 Gr.22 is widely used in hydrotreaters, hydrocrackers, reactor vessels, fractionation towers, and high-temperature heat exchangers.
Thermal Power Plants
In thermal power plants, SA387 Gr.22 is commonly specified for boiler steam drums, superheater headers, reheater headers, and high-pressure steam piping.
Fertilizer and Chemical Processing
SA387 Gr.22 is extensively used in ammonia converters, shift reactors, pressure vessels, and shell-and-tube heat exchangers.
Oil & Gas Processing
For oil and gas facilities, SA387 Gr.22 is an ideal material for high-pressure separators, gas processing vessels, surge drums, and process heaters.
Why Choose Us?
Comprehensive Inspection Services
Quality verification includes chemical composition analysis, tensile testing, hardness testing, ultrasonic testing (ASTM A578), dimensional inspection, and visual surface inspection. Third-party inspections by SGS, TÜV, BV, DNV, or LR are also available to meet project specifications.
Customized Processing Solutions
In addition to supplying steel plates, GNEE provides CNC flame cutting, plasma cutting, beveling, drilling, edge preparation, rolling, and marking. Customized dimensions help reduce material waste, machining time, and fabrication costs for pressure vessel manufacturers.
Reliable Inventory and Global Delivery
A wide range of standard thicknesses and plate sizes are maintained to support fast project schedules. With extensive export experience, GNEE provides seaworthy packaging, container or bulk vessel shipment, and complete export documentation, ensuring efficient delivery to customers worldwide.
FAQ
Q: What are the fundamental differences between SA387 Gr.22 and Gr.11 (1.25Cr-0.5Mo)?
A: SA387 Grade 22 (2.25Cr-1Mo) and Grade 11 (1.25Cr-0.5Mo) are both chromium-molybdenum alloy pressure vessel steels. The primary differences are in their alloy content-Gr.22 has double the chromium and molybdenum-which gives Gr.22 significantly higher temperature tensile strength and creep resistance for severe industrial applications.
Q: How should one choose between SA387 Gr.22 Class 1 and Class 2? Are they interchangeable?
A: Choose Class 2 for high-stress or thinner-walled pressure vessels where maximum mechanical strength is required. Choose Class 1 for applications where greater ductility, easier forming, and better weldability are prioritized. They are not directly interchangeable in design calculations due to different allowable stress values.
Q: What are the respective advantages of SA387 Gr.22 compared to Gr.21?
A: SA387 Grade 22 features higher chromium and molybdenum content (2.25% Cr, 1.00% Mo) than Grade 21 (3.00% Cr, 1.00% Mo). Its primary advantages include superior high-temperature creep resistance, better oxidation resistance in extreme heat, and stronger resistance to hydrogen attack in petrochemical processing.
Q: Can Gr.22 (2.25Cr-1Mo) and SA516 Gr.70 (C-Mn carbon steel) be substituted for one another?
A: Gr.22 (2.25Cr-1Mo) and SA516 Gr.70 cannot be indiscriminately substituted for one another. While both are used in pressure vessels, Grade 22 is an alloy steel designed for high-temperature creep resistance, whereas SA516 Gr.70 is a carbon-manganese steel meant for low-to-moderate temperature service.
Q: How should one choose between SA387 Gr.22 and Gr.91 for high-temperature service conditions?
A: When choosing between SA387 Gr. 22 and Gr. 91, one must weigh factors such as temperature limits, mechanical strength, and fabrication complexity. Gr. 91 is a Creep Strength Enhanced Ferritic (CSEF) steel specifically designed for higher operating temperatures, whereas Gr. 22 is a conventional 2¼Cr-1Mo alloy suitable for milder service conditions.
