SA 387 GR 11 refers to a specific grade of steel plate under the ASTM A387 standard. Here's a breakdown: - SA: Stands for "Specification for Alloy Steel" (ASTM standard) - 387: Indicates the specific standard number for alloy steel plates - GR: Stands for "Grade" - 11: Refers to the grade number, in this case, Grade 11 ASTM A387 Grade 11 is a chromium-molybdenum alloy steel plate designed for high-temperature applications, such as: - Pressure vessels - Boilers - Heat exchangers - Piping systems Grade 11 has a chromium content of 1.25% and a molybdenum content of 0.5%. It offers excellent resistance to corrosion, oxidation, and high-temperature scaling. The mechanical properties of SA 387 GR 11 include: - Tensile strength: 60-85 ksi (415-585 MPa) - Yield strength: 35-55 ksi (240-380 MPa) - Elongation: 18-22% in 8 in (200 mm) This grade is commonly used in industries like power generation, petrochemical, and oil refining, where high-temperature resistance and corrosion resistance are critical.