ASTM A387 Grade 12 Class 1 is a chromium-molybdenum (Cr-Mo) alloy steel plate designed for weldable boilers, pressure vessels, and industrial equipment used in elevated temperature service, particularly in the oil, gas, and petrochemical industries.
Specifications for ASTM A387 Grade 12 Alloy Steel Plates
| Designation | Nominal Chromium Content (%) |
Nominal Molybdenum Content (%) |
| A387 Grade 12 | 1.00% | 0.50% |
Tensile Requirements for ASTM A387 Grade 12 Alloy Steel Plates Class 1 Plates
| Designation: | Requirement: | Grade 12 |
| A387 Grade 12 | Tensile strength, ksi [MPA] | 65 to 85 [450 to 585] |
| Yield strength, min, ksi [MPa]/(0.2% offset) | 40 [275] | |
| Elongation in 8 in. [200mm], min % | 19 | |
| Elongation in 2 in. [50mm], min, % | 22 | |
| Reduction of area, min % | ––– |
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 |
Applications
Pressure Vessels & Boilers: Used in industrial boilers, storage tanks, and pressure vessels for safe containment of hot liquids/gases, ensuring structural stability under long-term high-temperature and high-pressure operating conditions.
Heat Exchangers: Efficient in shell-and-tube units, reheaters, and coolers due to good thermal conductivity and strength, maintaining reliable heat transfer performance without deformation during thermal cycling.
Oil & Gas Industry: Common in refineries for piping, manifolds, and process equipment handling hot fluids, also for sour service, resisting H₂S corrosion and adapting to harsh onshore and offshore extraction environments.
Petrochemical & Chemical Plants: Suitable for various equipment requiring corrosion resistance at elevated temperatures, such as reactors and fractionation towers, to cope with the erosion of acidic/alkaline chemical media.
Advantages
High-Temperature Strength: Molybdenum content provides excellent tensile strength and creep resistance at elevated temperatures.
Corrosion Resistance: Chromium content enhances resistance to oxidation and corrosive media, including sour environments.
Weldability: Good weldability makes it suitable for fabricating complex components like vessels and piping.
Cost-Effectiveness: A good balance of performance and cost for moderate conditions, offering a lower cost than higher-grade alloys.
Moderate Service Performance: Ideal for applications where extreme conditions aren't present but reliability is crucial, with specific mechanical properties (lower tensile strength than Class 2) for these needs.
Request a professional quotation for ASTM A387 Grade 12 Class 1 from GNEE Steel.
What is ASTM A387?
A high quality chrome molybdenum alloy steel plate intended specifically for use in weldable carbon steel pressure vessels at elevated temperatures. Added molybdenum gives the material greater temperature tensile strength and the chromium provides improved corrosion resistance.
What is the ASTM A387 equivalent to?
Among the ASTM A387 Grade 22 equivalent steel grades, SA387 Grade 22, 10CrMo9-10 is more popular than other equivalents. SA387 Grade 22 steel is under ASME SA387/ SA387M standard. The chemical performance and technical requirements of SA387 Grade 22 steel is almost same with ASTM A387 Grade 22 steel.