The 45Cr steel under the GB 3077 standard is a medium-carbon quenched and tempered alloy structural steel, characterized by high strength, high wear resistance, and excellent hardenability, while offering cost-effectiveness and process adaptability.
1. Automotive Manufacturing
Core Components:
Gears: After quenching and tempering, the tensile strength reaches ≥1,030 MPa, and surface high-frequency quenching achieves a hardness of HRC 52-58, meeting high-load transmission requirements.
Shaft Components: Such as drive shafts and half shafts, the 840°C oil quenching + 520°C tempering process balances strength and toughness, adapting to complex operating conditions.
Sleeves and Pins: In engine and transmission modules, enduring high-frequency friction and impact, the wear resistance of 45Cr steel significantly extends service life.
2. Machining Industry
Typical Applications:
Mold Bases: After quenching and tempering (850°C quenching + 550°C tempering), the tensile strength reaches ≥800 MPa. A 1.5 m³ standard mold base exhibits deformation <0.15 mm under a 30-ton clamping force, with a service life 2.3 times longer than that of Q235 steel.
Wear-Resistant Parts: Such as ejector sleeves, when used in conjunction with SKD61 after surface high-frequency quenching, the cost per unit is reduced by 40%, maintaining a fit clearance <5 μm after 200,000 continuous stamping cycles.
Transmission Structural Components: Gears with a module (m) of 3 operate continuously for 200 hours at 800 rpm without failure, demonstrating excellent machinability (relative cutting rate Kr = 0.65).
3. Rail Transit and Heavy Machinery
Key Components:
Axles and Wheel Hubs: Enduring high loads and vibrations, the fatigue resistance of 45Cr steel surpasses that of ordinary carbon steel, reducing the risk of crack initiation.
Connectors and Fasteners: Such as bolts and nuts, after quenching + low-temperature tempering, achieve a hardness of HRC 45-50, meeting heavy-duty connection requirements.
4. Industrial Mold Sector
Application Scenarios:
Plastic Molds: After TD treatment, mold inserts exhibit wear resistance equivalent to P20 steel, reducing material costs per mold by 28% and saving over RMB 1.2 million annually in procurement expenses.
Die-Casting Molds: Used in conjunction with H13 steel, they withstand high-temperature impacts during aluminum and zinc alloy die-casting, extending mold life by 1.5 times.
