ASTM A387 Grade 12 Class 1 is a Cr-Mo alloy steel plate per ASTM A387/A387M, engineered for high-temperature and high-pressure service. Supplied normalized (unlike quenched-and-tempered Class 2), it balances ductility, toughness and weldability, and is widely used in industrial boilers, heat exchangers, refinery reactors and sour-service oil and gas equipment.
Chemical Requirements for ASTM A387 Grade 12 Alloy Steel Plates
| Element | Chemical Composition (%) | |
| ASTM A387 Grade 12 | ||
| Carbon: | Heat Analysis: | 0.05 - 0.17 |
| Product Analysis: | 0.04 - 0.17 | |
| Manganese: | Heat Analysis: | 0.40 - 0.65 |
| Product Analysis: | 0.35 - 0.73 | |
| Phosphorus: | Heat Analysis: | 0.035 |
| Product Analysis: | 0.035 | |
| Sulphur (max): | Heat Analysis: | 0.035 |
| Product Analysis: | 0.035 | |
| Silicon: | Heat Analysis: | 0.15 - 0.40 |
| Product Analysis: | 0.13 - 0.45 | |
| Chromium: | Heat Analysis: | 0.80 - 1.15 |
| Product Analysis: | 0.74 - 1.21 | |
| Molybdenum: | Heat Analysis: | 0.45 - 0.60 |
| Product Analysis: | 0.40 - 0.65 |
Mechanical Property
|
Grade |
A387 Gr.12 CL.1 Mechanical Property |
|||
|
Thickness |
Yield |
Tensile |
Elongation |
|
|
A387 Gr.12 Cl.1 |
mm |
Min Mpa |
Mpa |
Min % |
|
t≦50 |
230 |
380-550 |
22 |
|
|
50<t≦200 |
- |
- |
18 |
|
Key Applications
Pressure Vessels & BoilersIdeal for the fabrication of industrial boilers, accumulators, and process vessels, delivering reliable structural stability for the safe containment and handling of high-temperature fluids and gases under long-term high-pressure operating conditions.
Heat ExchangersHighly efficient for shell-and-tube heat exchangers, industrial coolers, and reheaters, thanks to its excellent thermal conductivity and mechanical strength that maintain stable heat transfer performance even during repeated thermal cycling.
Refinery & PetrochemicalWidely adopted in high-temperature piping systems, process manifolds, boiler headers, and storage tanks for hot process fluids, withstanding the corrosive and thermal stress of crude oil refining, chemical synthesis, and intermediate product handling processes.
Oil & GasSuited for critical onshore and offshore equipment operating in sour service environments containing hydrogen sulfide, providing robust corrosion resistance and structural integrity to ensure safe operation in harsh extraction, transportation, and processing scenarios.
General IndustrialCommonly applied in chemical processing equipment, industrial condensers, and various heavy-duty machinery components, meeting the rigorous performance demands of high-temperature, high-wear industrial working conditions.
Get an valued quotation for ASTM A387 Grade 12 Class 1, Contact GNEE Steel.
Can ASTM A387 Grade 12 Class 1 be used for low-temperature service scenarios?
No, it is not recommended for low-temperature applications. This steel grade is optimized for high-temperature and high-pressure working conditions, and its toughness may decline significantly at low temperatures, which cannot meet the safety requirements of low-temperature pressure-containing equipment.
What are the standout performance advantages of ASTM A387 Grade 12 Class 1 in practical applications?
Its key advantages include excellent high-temperature creep resistance and oxidation resistance, good corrosion resistance to sour media containing hydrogen sulfide, reliable weldability for on-site fabrication, and stable mechanical properties that prevent deformation under long-term thermal stress.