A387 Grade 9 Class 2 chromemolybdenum plate is an ideal material for welded pressure vessels and boilers used in elevated temperature service. With excellent resistance to high temperature and corrosion, this type of steel is commonly used in the petrochemical, oil, gas and power generation industry. ASTM A387 Grade 5 Class 2 Steel PlatesA387 GR 5 CL 1A387 Gr5CL1 STEEL PLATE__Steel SupplierASTM A387 GRADE 5 CLASS 1A387 Gr.5 CL.1 STEEL PLATE . ASTM A387 Gr 5 CL 1 is a chromium molybdenum alloy steel plate intended primarily for welded boiler and pressure vessels designed of elevated temperature service. The Cr content 5.00% and the Mo content0.5%.