Alloy Steel Grade 91 is a ferritic-martensitic steel, highly suitable for applications requiring high-temperature strength and creep resistance. Its composition includes 9% chromium, 1.2% molybdenum, 0.2% vanadium and 0.2% nitrogen as primary alloying elements (other elements present in trace amounts). As well as its excellent mechanical properties, Alloy Steel Grade 91 has superior thermal stability, making it a great choice for manufacturing boilers, pressure vessels and steam turbines operating at extreme temperatures.

Alloy Steel Grade 91 (9Cr-1Mo) is a chromium-molybdenum alloy steel with outstanding oxidation and corrosion resistance, high tensile and creep strength, excellent heat resistance and stress rupture cracking properties. It is commonly used in power plants for turbine components such as rotors, shafts and casing liners due to its superior creep strengths at elevated temperatures. Additionally, it can be found in parts like boiler tubing hangers, which require flexibility at low temperatures. Other applications include pressure vessels for petrochemical reactors or oil and gas production, valves with high-temperature requirements and chemical process equipment.