15Mo3

15Mo3 steel plate is a low-alloy heat-resistant steel specifically designed for pressure equipment subjected to sustained stress in high-temperature environments, particularly suitable for medium-temperature and medium-pressure boilers and pressure vessels. Its technical requirements are primarily governed by the European standard EN 10028-2:2022 "Flat products made of steels for pressure purposes – Part 2: Non-alloy and alloy steels with specified elevated temperature properties". This standard is the core international specification widely adopted for pressure equipment steels, clearly defining the chemical composition, mechanical properties, high-temperature strength, impact toughness, dimensional tolerances, test methods, and quality assurance requirements for 15Mo3. As a classic alloy steel grade within the EN 10028-2 standard, 15Mo3 is extensively used in Europe and in countries adopting the European Pressure Equipment Directive (PED), suitable for pressure components operating at temperatures up to 500°C. It is a time-tested and technically mature high-temperature pressure material widely applied in industrial fields.

The designation "15Mo3" consists of three parts: "15" indicates an average carbon content of approximately 0.15% (expressed in hundredths of a percent), placing it in the low-carbon steel category, which ensures good weldability and adequate toughness; "Mo" is the chemical symbol for molybdenum; "3" signifies a molybdenum content of approximately 0.30%. The addition of molybdenum is the key characteristic of 15Mo3 steel. Molybdenum significantly enhances the steel’s high-temperature strength and creep resistance. At elevated temperatures, molybdenum forms stable carbides that effectively inhibit grain growth and dislocation movement, thereby greatly improving the microstructural stability and resistance to deformation under long-term high-temperature service conditions. Additionally, 15Mo3 typically contains small amounts of manganese (Mn) and silicon (Si), and may be deoxidized with aluminum (Al) or titanium (Ti) to refine the grain structure, further optimizing its overall performance.

The primary applications of 15Mo3 steel plate are in the energy, power generation, chemical, and thermal systems sectors, suitable for manufacturing pressure equipment operating continuously under medium-temperature conditions, including:

    Boiler Components: Used for high-temperature parts such as superheater tubes, headers, and steam pipes in industrial and power station boilers.
    Pressure Vessels: Used in petrochemical industries for reactors, heat exchanger shells, and separation equipment operating at elevated temperatures.
    Thermal Systems: Used for critical structural components in high-temperature steam pipelines, heat exchangers, and thermal networks.
    Industrial Furnace Equipment: Used for pressure-bearing components in high-temperature industrial furnaces such as heating furnaces and cracking furnaces.

Key characteristics include: good high-temperature strength (maintaining high allowable stress within the 450–500°C range), excellent creep resistance, good weldability (requiring preheating of 150–250°C, with post-weld stress relief annealing recommended), and favorable cold and hot formability. As a technically mature and reliable low-alloy heat-resistant steel, 15Mo3 plays a vital role in ensuring the safe, stable, and long-term operation of high-temperature pressure equipment and remains an indispensable high-temperature structural material in modern industry.