Alloy Steel Grade 9 is a low-alloy steel that contains Nickel, Chromium and Molybdenum as its main alloying elements. This alloy provides excellent strength, toughness, and thermal stability. The composition of Grade 9 includes 0.20–0.25% Carbon (C), 8%-9% Nickel (Ni), 1.-1.75 % Chromium (Cr) and 0.4 – 0.5 % Molybdenum (Mo). Moreover, it also has small amounts of Copper (Cu) for enhanced corrosion resistance in combination with a higher temperature operating range compared to other grades of stainless steel alloys. In addition to being used in the oil & gas industry, this grade is known for its use in applications with elevated temperatures, such as turbochargers and exhaust manifolds, due to its good creep properties at elevated temperatures up to 600 °F (316 °C).

Alloy Steel Grade 9 (ASTM A387 Grade 9) is a high-quality chromium-molybdenum alloy steel plate for pressure vessels and industrial boilers. This steel grade offers excellent heat resistance, corrosion resistance, and high strength at elevated temperatures. It also displays good weldability characteristics when compared to other steels, such as stainless steel. ASTM A387 Grade 9 can be easily machined, formed, and welded while still performing better than other steel grades. Adding molybdenum allows for higher tensile strengths than those achievable with just chrome-molybdenum or regular steels alone. ASTM A387 Grade 9 is easy to machine and provides exceptional wear resistance properties, making it suitable for various engineering applications such as the fabrication of pump components and marine structures.