SA 387 GR 22 CL 1 / CL 2 – High-Strength Cr-Mo Steel for Elevated Temperature and Pressure SA 387 Grade 22 Class 1 and Class 2 plates are alloy steels enriched with 2.25% chromium and 1% molybdenum, offering a powerful combination of high-temperature strength, oxidation resistance, and excellent creep performance. These plates are ideal for pressure-containing applications in thermal processing, power generation, refineries, and petrochemical systems, especially where components must endure long-term exposure to high temperatures and pressure. Class 1 is suited for standard temperature service, while Class 2 offers higher tensile strength for more demanding thermal loads. Key Highlights: Excellent High-Temperature Durability: Designed for sustained use in environments up to ~620°C, with long-term mechanical stability and creep resistance. Cr-Mo Alloy Composition: The 2.25Cr-1Mo blend ensures oxidation protection, strength retention, and resistance to hydrogen attack in high-heat conditions. Flexible Strength Classes: Class 1 offers a balanced approach, while Class 2 provides superior mechanical properties under thermal and mechanical stress. Strong Fabrication Capabilities: Good weldability and formability with appropriate heat treatment procedures, suitable for complex pressure vessel fabrication. Mechanical Properties Overview: Property SA 387 Gr 22 Cl 1 SA 387 Gr 22 Cl 2 Yield Strength ≥ 205 MPa ≥ 220 MPa Tensile Strength 415–585 MPa 515–690 MPa Elongation ≥ 20% ≥ 18% Max Temperature Up to ~620°C Up to ~620°C Typical Applications: Superheaters, reheaters, and steam piping systems Heat exchangers and thermal reactors in refineries Power plant pressure vessels and high-pressure drums Hydrogen and ammonia service vessels in petrochemical units Conclusion: SA 387 GR 22 CL 1 / CL 2 is a trusted alloy steel for pressure vessels and components exposed to aggressive thermal cycles and high-pressure service. Its ability to maintain strength, resist oxidation, and perform under stress makes it a top-tier material choice in the most demanding industrial environments.