◦ Implementation standard: GB/T1222-2007.
◦ Density: 7.85 g/cm3.
• Chemical composition
◦ Carbon (C): 0.62%~0.70%, providing basic strength and hardenability.
◦ Manganese (Mn): 0.90%~1.20%, improving hardenability and enhancing toughness.
◦ Silicon (Si): 0.17%~0.37%, improving processing performance and refining grains.
◦ Phosphorus (P): ≤0.035%, sulfur (S) ≤0.035%, strictly controlling impurity content.
◦ Chromium (Cr): ≤0.25%, nickel (Ni) ≤0.30%, copper (Cu) ≤0.25%, trace alloying elements, assisting in improving performance.
• Mechanical properties
◦ High strength: The tensile strength σb is 825MPa~925MPa, and some data are above 980MPa. It has excellent bearing capacity and is suitable for high stress conditions.
◦ Good elasticity: It has a high elastic limit, can withstand large elastic deformation without permanent deformation, and can accurately store and release energy.
◦ High hardness: After heat treatment, it can reach HRC50 or above, with significant wear resistance, suitable for wear conditions.
◦ Good toughness: When subjected to impact loads, it can absorb a certain amount of energy without brittle fracture, which improves reliability and service life under complex conditions.
• Characteristics
◦ High hardenability: Manganese significantly improves hardenability, suitable for manufacturing springs and large parts with a diameter of more than 20mm.
◦ Low tendency of surface decarburization: The surface quality is stable during heat treatment, reducing the risk of early failure.
◦ Overheat sensitivity and tempering brittleness: The quenching temperature must be strictly controlled, and the brittle temperature range must be avoided during tempering.
◦ Good processing performance: can be forged and welded, suitable for manufacturing complex-shaped parts, but the cold deformation plasticity is low.
• Heat treatment specifications
◦ Quenching: Quenching temperature 830℃±20℃, oil cooling.
◦ Tempering: Tempering temperature 540℃±50℃, ±30℃ when special needs.
◦ Normalizing: Temperature 810±10℃, air cooling.
• Application areas
◦ Spring manufacturing: such as automobile leaf springs, shock absorber springs, valve springs, clutch reeds, etc.
◦ Mechanical parts: can be used to manufacture high-load, high-friction parts such as gears, bearings, and pistons.
◦ Cutting tools and stamping dies: using its high hardness and wear resistance, it can be used to manufacture cutting tools, stamping dies, etc.
◦ Buildings and bridges: can be used to manufacture components that enhance the bearing capacity of structures, such as bridge bearings, building supports, etc.
Post time: Jul-18-2025