SA 387 GR 9 CL 1 / CL 2 – High-Chrome Alloy Steel for Elevated Temperature Service SA 387 Grade 9 Class 1 and Class 2 are 9% chromium, 1% molybdenum alloy steels developed for high-temperature pressure vessels and heat-exposed systems. The higher chromium content provides improved oxidation, creep, and corrosion resistance, making them ideal for service in refineries, hydrogen processing, and thermal power generation. Class 2 offers superior strength and is commonly selected for higher-stress applications. Key Highlights: Superior Oxidation Resistance: High chromium level protects against scaling in hot conditions. Enhanced Thermal Stability: Maintains mechanical performance under prolonged high heat. Reliable Fabrication and Welding: Suitable for all standard processes with proper thermal control. Flexible Mechanical Classes: Class 1 for standard, Class 2 for high-strength performance. Mechanical Properties Overview: Property SA 387 Gr 9 Cl 1 SA 387 Gr 9 Cl 2 Yield Strength ≥ 220 MPa ≥ 240 MPa Tensile Strength 415–585 MPa 515–690 MPa Elongation ≥ 20% ≥ 18% Max Temperature Up to ~650°C Up to ~650°C Typical Applications: Heat exchangers and high-pressure boilers Hydrogen reformers and thermal reactors Power plant piping and headers Petrochemical pressure equipment in hot, corrosive service