SA 387 GR 11 CL 1 / CL 2 – Versatile Chrome-Moly Steel Plate for Elevated Temperature Pressure Vessels SA 387 Grade 11 Class 1 and Class 2 are chrome-moly alloy steels widely used in pressure vessels and industrial boilers operating in moderate to high temperature conditions. Alloyed with 1.25% chromium and 0.5% molybdenum, these plates provide a reliable combination of thermal resistance, oxidation protection, and good weldability, making them a go-to material in power, petrochemical, and refinery sectors. While Class 1 provides good strength for standard duties, Class 2 offers enhanced mechanical performance, suited for higher-stress service environments. Key Highlights: Stable at Elevated Temperatures: Reliable performance in temperatures up to ~600°C, with resistance to heat-related degradation. Improved Corrosion Resistance: Alloying elements provide durability in environments containing steam, hydrogen, or light acidic exposure. Good Weldability and Fabrication: Easily welded and formed with standard procedures, ideal for field fabrication and repairs. Two Strength Classes for Flexibility: Class 1 meets standard pressure vessel needs, while Class 2 is designed for greater strength and thermal resilience. Mechanical Properties Overview: Property SA 387 Gr 11 Cl 1 SA 387 Gr 11 Cl 2 Yield Strength ≥ 205 MPa ≥ 220 MPa Tensile Strength 415–585 MPa 515–690 MPa Elongation ≥ 20% ≥ 18% Max Temperature Up to ~600°C Up to ~600°C Typical Applications: Boilers, steam drums, and pressure vessels in power plants Heat exchangers and refinery equipment Hydrogen gas systems and petrochemical vessels Superheaters and reheaters requiring moderate creep resistance Conclusion: SA 387 GR 11 CL 1 and CL 2 are reliable alloy steel plates tailored for use in high-temperature and moderately corrosive environments. Their balance of mechanical strength, fabrication ease, and cost-effectiveness makes them a trusted choice for engineers and fabricators across various thermal processing and pressure-containing applications.