21CrMoV5-7, 1.7709 – High-toughness, heat-resistant steel with excellent wear resistance

This is a low-alloy Cr-Mo-V bainitic steel, suitable for elevated temperatures and heat-resistant. For large forgings – easily formable and machinable. Resistant to corrosion in high-pressure hydrogen environments up to approximately 320 °C. In steam environments up to approximately 600 °C. Intended primarily for connection parts in power and chemical industry equipment. Additionally used for the manufacturing of steam turbine rotors, shafts, and impeller discs of compressors. Weldability is guaranteed conditionally (must be preheated to a temperature of 350–400 °C). Drawn and rolled bars d 12 mm – d 300 mm in stock, forged bars, blocks and hexagons available on order.
The metallurgical industry focuses on a wide range of steel types, including low-alloy bainitic heat-resistant steel. The material 21CrMoV5-7, 1.7709, is a type of heat-resistant steel, ideal for the production of large-size forgings. It is used, for example, for shafts and impellers of compressors, steam turbine rotors, and components in chemical and power generation industries. Steel alloyed with chromium, vanadium, and molybdenum is also resistant to corrosion at higher pressures and temperatures up to 320 and 600 degrees Celsius, respectively.

Drawn and rolled bars from 12 mm to 300 mm in diameter in stock. Forged bars, blocks, hexagons available on request.

Mechanical properties

• Tensile strength: Steel of this grade exhibits high tensile strength. This makes it ideal for applications where high mechanical demands are required.
• Hardness: Due to the alloying elements of chromium, molybdenum, and vanadium, the steel has high hardness and wear resistance.
• Temperature resistance: This steel is known for its excellent resistance to high temperatures, making it ideal for use in temperature-critical applications.

Physical properties

• Density: The density of this steel is approximately 7.8 g/cm³.
• Melting point: 21CrMoV5-7, 1.7709 steel has a high melting point, which contributes to its resistance to high temperatures.

Chemical composition

21CrMoV5-7, 1.7709 steel has a specific chemical composition that gives it its unique properties. The main elements included in this steel are:

• Chromium (Cr): 2.00–2.50% – Enhances hardness and corrosion resistance.
• Molybdenum (Mo): 0.90–1.20% – Improves strength and resistance to high temperatures.
• Vanadium (V): 0.20–0.30% – Increases strength and wear resistance.
• Carbon (C): 0.17–0.23% – Increases hardness and tensile strength.
• Silicon (Si): 0.15–0.35 % – Improves the overall strength of the steel.
• Manganese (Mn): 0.20–0.40% – Contributes to better mechanical properties.
• Phosphorus (P) and Sulphur (S): max. 0.025% – These elements are present in small quantities and their content is controlled to achieve optimum steel properties.

Industrial applications

21CrMoV5-7, 1.7709 steel has a wide range of applications in various industries due to its unique properties.

Power industry

In the power industry, this steel is often used to make components that are exposed to high temperatures and pressures, such as pipes and connection parts in boilers and steam turbines.

Automotive industry

21CrMoV5-7, 1.7709 steel is used for engine parts that require high strength and wear resistance, such as crankshafts, camshafts and piston rings.

Aerospace industry

Due to its resistance to high temperatures and excellent mechanical properties, this steel is suitable for the production of aircraft engine components and other critical parts.

Petrochemical industry

In the petrochemical industry, 21CrMoV5-7, 1.7709 steel is used for the production of equipment exposed to corrosive environments and high temperatures, such as reactors.