First, Chemical Composition of 12CrMoG High-Pressure Seamless Steel Pipe.
12CrMoG is an alloy steel pipe with chromium and molybdenum as its main alloying elements. The chromium content is approximately 0.8-1.2%, and the molybdenum content is approximately 0.4-0.6%. Chromium improves the steel’s oxidation resistance and corrosion resistance, while molybdenum improves its thermal strength, i.e., its strength at high temperatures and creep resistance. It also contains carbon, typically 0.08-0.15%, which ensures the steel’s basic strength. Small amounts of silicon and manganese are also present; silicon improves the steel’s strength and hardness, while manganese improves its toughness.
Second, Manufacturing Process and Quality Control of 12CrMoG High-Pressure Seamless Steel Pipe.
- Seamless steel pipe manufacturing process: Generally, hot rolling or cold rolling (cold drawing) processes are used. Hot rolling involves heating a steel billet to a high temperature, piercing it through a piercing mill, and then rolling it through a tube rolling mill. For example, the billet is first heated to approximately 1200℃, pierced using a skew rolling mill, and then rolled through multiple tube rolling mills to gradually thin and homogenize the steel pipe wall. Cold rolling (cold drawing) is based on hot rolling, involving drawing or cold rolling at room temperature, resulting in more precise dimensions and better surface quality, but at a relatively higher cost.
- Quality Control: For 12CrMoG high-pressure seamless steel pipes and high-pressure boiler steel pipes, strict quality control is implemented during production. This includes raw material inspection to ensure the alloy element content meets standards; controlling the dimensional accuracy of the steel pipe during rolling, such as the tolerance range of outer diameter and wall thickness; and performing non-destructive testing, such as ultrasonic testing and magnetic particle testing, to detect internal and surface defects in the steel pipe.
Third, Performance Characteristics of 12CrMoG High-Pressure Seamless Steel Pipe.
- High-Temperature Performance: It possesses excellent mechanical properties in high-temperature environments, capable of withstanding the pressure of high-temperature steam in high-pressure boilers. Its allowable stress remains at a high level at high temperatures; for example, at 500℃, the allowable stress can reach approximately 100MPa, making it suitable for high-temperature and high-pressure working environments.
- Corrosion Resistance: Due to the presence of chromium and molybdenum, 12CrMoG high-pressure seamless steel pipe exhibits good corrosion resistance. In environments containing water vapor, carbon dioxide, and other media, it effectively resists corrosion, preventing pipe wall thinning and damage.
- Welding Performance: This material has good weldability. Through appropriate welding processes, such as manual arc welding, and the selection of suitable welding rods (such as R307 welding rods), the quality of the welded joint can be guaranteed, ensuring that it maintains good performance after welding.
Fourth, the differences in applications of 12CrMoG high-pressure seamless steel pipes.
1. 12CrMoG high-pressure seamless steel pipes: Widely used for transporting high-temperature, high-pressure fluid media, such as oil and gas in the petrochemical industry, and steam in thermal power plants.
2. 12CrMoG high-pressure boiler tubes: Primarily used in the heating surfaces of high-pressure boilers, such as superheaters, reheaters, and water-cooled walls. During boiler operation, these parts are subjected to the scouring of high-temperature, high-pressure steam and flames. 12CrMoG high-pressure boiler steel pipes ensure the safe and stable operation of the boiler.
Post time: Nov-10-2025