First, the material composition of 42CrMo seamless steel pipe:
42CrMo seamless steel pipe is a medium-carbon alloy structural steel. Its chemical composition includes approximately 0.38%-0.45% carbon, 0.90%-1.20% chromium, and 0.15%-0.25% molybdenum. This alloying ratio gives the material excellent overall performance:
- Highly balanced strength and toughness: Tensile strength can reach over 1080 MPa, yield strength ≥930 MPa, while maintaining an elongation of over 12%, making it suitable for use under alternating loads.
- Excellent heat treatment properties: After quenching and tempering (quenching + high-temperature tempering), the hardness can reach HRC28-32, with a hardenability superior to ordinary carbon steel. Uniform hardening is achieved even for cross-sections ≤100 mm in diameter. – High-temperature and corrosion resistance: The addition of molybdenum significantly improves creep resistance, maintaining stable performance in environments below 500°C; chromium enhances oxidation resistance, making it suitable for high-temperature equipment such as power plant boilers and heat exchangers.
Second, the production process of 42CrMo seamless steel pipe:
42CrMo seamless steel pipe is primarily produced using hot rolling or cold drawing processes:
- Hot rolling: The round billet is heated to approximately 1200°C, perforated, and then rolled to the desired dimensions on a tube mill. This process offers high production efficiency and is suitable for large-scale production, but the product’s surface quality and dimensional accuracy are relatively low.
- Cold drawing: Multiple passes of the hot-rolled billet are drawn at room temperature, achieving higher dimensional accuracy and surface quality, but this increases production costs.
- Heat treatment: Regardless of the forming process used, subsequent heat treatment is crucial. Quenching and tempering (quenching followed by high-temperature tempering) are typically used to achieve a tempered bainite structure, which is a key step in ensuring the overall performance of 42CrMo steel pipe.
Third, the application areas of 42CrMo seamless steel pipe:
42CrMo seamless steel pipe is widely used in various fields due to its excellent performance:
- Oil drilling equipment: Used in key components such as drill collars and drill pipe joints, its service life is 40% longer than 35CrMo steel at depths of 8,000 meters.
- Hydraulic props: Pipes used in coal mine hydraulic supports require a compressive strength of ≥900 MPa. 42CrMo steel, after special heat treatment, fully meets the GB/T17396-2009 standard.
- High-end machinery manufacturing: Applications such as wind turbine main shaft bearing rings and heavy truck drive shafts can see a premium of 2-3 times that of ordinary pipe.
- Mold industry applications: When 42CrMo seamless steel pipe is used in hot work mold inserts, the thermal fatigue resistance is increased by 15%-20% compared to H13 steel.
Fourth, corresponding grades of 42CrMo seamless steel pipes.
42CrMo seamless steel pipes have corresponding grades in different countries and regions, as follows:
ISO grade: 42CrMo4
Japanese grade: SCM440
German grade: 42CrMo4 or 1.7225
US grade: 4140 or G41400
Post time: Sep-11-2025