15CrMoG seamless steel pipe is an alloy steel widely used in high-temperature and high-pressure environments. Its excellent properties make it a key material in industries such as power generation, petrochemicals, and boiler manufacturing. Based on a chromium-molybdenum alloy, this seamless steel pipe is produced through a specialized production process. It exhibits excellent resistance to high temperatures, high pressures, and corrosion, meeting the demands of extreme operating conditions.
In terms of chemical composition, the main alloying elements of 15CrMoG seamless steel pipe are chromium and molybdenum, with chromium content ranging from approximately 1.00% to 1.50% and molybdenum content ranging from approximately 0.45% to 0.65%. The addition of these two elements significantly improves the steel’s high-temperature strength and oxidation resistance. Chromium forms a dense oxide film on the steel surface, effectively preventing further oxidation, while molybdenum enhances the steel’s thermal strength and creep strength, maintaining excellent mechanical properties even at high temperatures. The steel also contains appropriate amounts of carbon, silicon, manganese, phosphorus, and sulfur, all of which are strictly controlled to ensure its overall performance.
In terms of production processes, 15CrMoG seamless steel pipes are primarily manufactured using hot rolling or cold drawing. The hot rolling process involves heating the steel billet to the appropriate temperature, piercing it with a piercing machine, and rolling it into a steel pipe. This method is highly efficient and suitable for large-scale production. The cold drawing process involves drawing the hot-rolled billet through a die at room temperature, resulting in steel pipes with higher precision and better surface quality. Regardless of the process used, strict control of parameters such as temperature and deformation is required during production to ensure that the microstructure and mechanical properties of the steel pipe meet standard requirements. Subsequent heat treatment, such as normalizing and tempering, is required to optimize the material’s microstructure and properties.
In terms of physical properties, 15CrMoG seamless steel pipes exhibit excellent performance. Its tensile strength typically ranges from 440 to 640 MPa, its yield strength is no less than 295 MPa, and its elongation can exceed 21%. These mechanical properties enable it to withstand the various stresses found in high-pressure environments. In terms of high-temperature performance, 15CrMoG seamless steel pipe maintains excellent strength below 500°C and can be used up to 550°C for short periods, demonstrating excellent creep resistance. Its coefficient of thermal expansion is approximately 12.5×10⁻⁶/°C, and its thermal conductivity is 42.7W/(m·K), crucial parameters for the design and calculation of high-temperature equipment.
15CrMoG seamless steel pipe has a wide range of applications. In the power industry, it is widely used in key components such as superheaters, reheaters, and main steam lines in supercritical and ultra-supercritical power plant boilers. In the petrochemical industry, it is often used in high-temperature and high-pressure equipment such as hydrogenation reactors and catalytic cracking units. In the boiler manufacturing industry, it is the preferred material for the heating surface steel pipes of various high-pressure boilers. It also has important applications in the nuclear power, metallurgy, and machinery manufacturing industries. These applications require the material to operate stably and long-term under harsh conditions such as high temperature, high pressure, and corrosive media. With its excellent performance, 15CrMoG seamless steel pipe fully meets these stringent requirements.
Compared to ordinary carbon steel, 15CrMoG seamless steel pipe offers significant performance advantages. First, it offers higher high-temperature strength. At the same temperature, its allowable stress is 2-3 times that of carbon steel. Second, it exhibits superior oxidation resistance, resulting in a longer service life in high-temperature steam environments. Third, it offers improved structural stability, making it less susceptible to degradation such as pearlite spheroidization during long-term operation at high temperatures. Compared to other alloy steels such as 12Cr1MoVG, 15CrMoG has a lower alloy content, offering a more cost-effective solution while still meeting the requirements of most medium-temperature and high-pressure operating conditions. While slightly inferior to higher-grade P91/P92 steels in high-temperature strength, it offers superior weldability and processability, making it more suitable for certain specific applications.
In actual use, welding 15CrMoG seamless steel pipe requires special care. Due to the presence of alloying elements such as chromium and molybdenum, cold cracking can easily occur during welding, necessitating appropriate preheating and post-weld heat treatment. Generally, the preheating temperature is controlled between 150-200°C, with the interpass temperature not exceeding 300°C. Post-weld tempering at 680-720°C is required to eliminate residual weld stress. Welding materials should be selected, such as wire or rods that match the base material, such as E5515-B2. Furthermore, heat input must be controlled during welding to avoid overheating, which can lead to performance degradation in the weld area.
From a market perspective, demand for 15CrMoG seamless steel pipes has steadily increased with the development of industries such as the power industry and petrochemicals. In particular, with the promotion of supercritical and ultra-supercritical power generation technologies, demand for high-performance boiler steel pipes continues to rise.
Regular inspection and maintenance are essential for 15CrMoG seamless steel pipes, especially for pipes subjected to long-term operation under high-temperature and high-pressure conditions. Wall thinning, surface oxidation, and structural degradation should be monitored, and replacement should be performed as necessary. Storage should be kept away from humid environments to prevent rust, and appropriate protective measures should be taken during transportation to prevent impact damage. Proper use and maintenance can significantly extend the service life of the pipes, improving the safety and economic efficiency of equipment operation.
In general, 15CrMoG seamless steel pipe, as a high-performance alloy steel pipe, plays an irreplaceable role in modern industry. Its rational alloy design, mature production process, and reliable performance make it an ideal choice for high-temperature and high-pressure working conditions. With the continuous development of my country’s industrial technology and the increasing requirements for material performance, 15CrMoG seamless steel pipe is bound to play a vital role in more fields, providing a strong guarantee for the safe and efficient operation of industrial equipment. In the future, through further optimization of composition design and production process, the performance of this material can be further improved, and its application prospects are very broad.
Post time: Aug-26-2025