ASTM A387 Grade 22 (ASME SA387 Grade 22) is a type of Chrome-Moly steel plate utilized in the fabrication of boilers and pressure vessels engineered for high-temperature and high-pressure services. This material contains a chromium content ranging from 2.00% to 2.50% and molybdenum between 0.90% and 1.10% for SA387 GRADE 22.
The elevated chromium levels contribute to improved corrosion and oxidation resistance. ASTM A387 Grade 22 / ASME SA387 Grade 22 material is suitable for storing oil, gas, or other liquids in various industries, and it is also compatible with sour services.
Standards Referenced for ASTM A387 Grade 22 CL1, CL2
ASTM:
- A20/A20M: General requirements for pressure vessel plates.
- A370: Test specification for mechanical properties of steel
- A435/A435M: Straight-beam ultrasonic examination of steel plates
- A577/A577M: Ultrasonic angle beam examination of steel plates
- A578/A578M: Straight beam UT examination of rolled steel plates in special applications
- A1017/A1017M: Specification for pressure vessel plates of alloy steel, chromium-molybdenum-tungsten
AWS (American Welding Society) Specification for Welding Methods:
- A5.5/A5.5M: Low alloy steel electrodes for shield metal arc welding.
- A5.23/A5.23M: Low alloy steel electrodes for fluxes for submerged arc welding.
- A5.28/A5.28M: Gas shielded arc welding
- A5.29/A5.29M: Flux cored arc welding.
ASTM A387/ ASME SA387 Grade 22 Chemical Composition
| Grade | Nominal Chromium Content, % | Nominal Molybdenum Content, % |
|---|---|---|
| 11 | 1.25 | 0.50 |
| 22, 22L | 2.25 | 1.00 |
| 5 | 5.00 | 0.50 |
| 9 | 9.00 | 1.00 |
| 91 | 9.00 | 1.00 |
Except 21L, 22L and 91, each grade is available in two classes of tensile strength levels as defined in the tensile requirements tables. Grades 21L and 22L only has Class 1, and Grade 91 only has Class2.
Heat Treatment for ASME SA387 Grade 22 CL1, CL2
ASTM A387 specifies that chrome moly alloy steel plates must be of killed steel, undergoing thermal treatment through methods such as annealing, normalizing, and tempering. Alternatively, if mutually agreed upon by the buyer, accelerated cooling from the austenitizing temperature can be performed through methods like air blasting or liquid quenching, followed by tempering. The minimum tempering temperatures are detailed in the table below:
| Grade | Temperature, °F [°C] |
|---|---|
| 2, 12 and 11 | 1150 [620] |
| 22, 22L, 21, 21L and 9 | 1250 [675] |
| 5 | 1300 [705] |
Our Product Range: Product: Chrome Moly Alloy Steel Plate ASME SA387/ ASTM A387 Grades Available: A/SA387 GRADE 11, 22, 12, 5, 9, 91 Manufacturing Methods: Hot Rolled, Heat Treated Thickness Range: 5 to 150 mm Width Range: 0.6m to 3m Length Options: 6m, 12m, custom lengths Surface Finish: Natural, Painted Packaging: Standard sea packing, bundled with steel strips. Customized Cutting: Laser Cut, Plasma Cut, CNC Cut.
