Bearing steel is the solid foundation of mechanical operation. Its extremely high hardness and wear resistance allow it to stand firm in a high-load working environment. Behind every precise rotation, there is the silent persistence of bearing steel. It is a trustworthy “steel guard” in the industrial field.The following content is based on the technical points of bearing steel selection, combined with industry general standards and material properties analysis, so that everyone can refer to it when selecting materials.
1. Core Performance Requirements of Bearing Steel
- Contact fatigue strength
The contact stress between the rolling element and the track of the bearing is as high as 1500-3000MPa, requiring the material to have ultra-high resistance to plastic deformation. It is recommended to choose GCr15 (SAE 52100) after vacuum degassing, whose fatigue life can reach 3 times that of ordinary steel. - Wear resistance index
The Rockwell hardness should reach HRC58-62. It is recommended to use M50NiL (AMS6278) with secondary hardening treatment, which can still maintain a surface hardness of more than HRC60 in high temperature environment. - Dimensional stability
Precision bearings (P4/P2 grade) require a dimensional change rate of ≤0.005% after heat treatment. It is recommended to use CSS-42L material containing Mo, which can effectively control the residual austenite content after low-temperature cold treatment.
2.Typical Working Condition Adaptation Scheme
| Working condition type | Recommended materials | Processing process | Limit parameters |
| Conventional load | GCr15 (AISI 52100) | Quenching + low temperature tempering | Contact stress ≤2500MPa |
| Corrosive environment | X65Cr13 (440C) | Vacuum quenching + cryogenic treatment | Cl- concentration ≤500ppm (80℃) |
| High temperature environment | M50 (AMS6491) | High temperature tempering (500℃×2h) | Continuous working temperature ≤315℃ |
| Ultra-high load | CBS1000 (carburizing steel) | Carburizing quenching (layer depth 1.5-2mm) | Impact load ≥100kN |
3. Analysis of Key Selection Dimensions
Load characteristic analysis
- Dynamic load: vacuum-melted ZGCr15 is preferred, and non-metallic inclusions are controlled at ASTM B level
- Impact load: 20Cr2Ni4A carburizing steel is used, with surface hardness HRC60-63 and core hardness HRC35-40
Heat treatment matching principle
Recommended martensitic quenching process:
- Austenitizing temperature: GCr15→850±10℃
- Quenching medium: graded oil quenching (120℃ hot oil)
- Tempering curve: 150-180℃×2-3h (three tempering)
Economic optimization model
| Cost level | Material options | Cost performance index | Applicable scenarios |
| Economic type | SUJ2 (JIS standard) | 9.2 | General machinery, automotive parts |
| Standard type | 100Cr6 (DIN) | 8.5 | Industrial motors, machine tool spindles |
| High-end type | Pyrowear 675 | 7.8 | Aircraft engine main bearings |
4. Special Working Condition Solutions
- Vacuum environment application
Use Cronidur30 (AMS5898) nitrided steel, vacuum outgassing rate <1×10^-6 Torr·L/s·cm², suitable for space mechanism bearings - Food grade environment
Recommend FDA-certified Nitronic60 (AMS5847), acid and alkali corrosion resistance index increased by 300% compared with 440C - Micro-vibration environment
Use Carpenter Custom465, elastic modulus 210GPa, can reduce vibration noise by more than 15dB
5. Key Points of Quality Control
- Ultrasonic flaw detection: According to ASTM E588 standard, the detection depth is ≥5mm, and the defect size is ≤φ0.4mm
- Carbide network: metallographic detection is controlled at ≤2 level according to SEP1520 standard
- Residual stress: X-ray diffraction detection, surface compressive stress should be ≥-400MPa
Summary
The rational selection of bearing steel is the cornerstone to ensure the performance and service life of bearings. From working condition analysis to material property comparison, every link is crucial. When you face complex working conditions and performance requirements, you must comprehensively weigh all factors. I hope this article can be your guide on the road to bearing steel selection, helping you make accurate decisions to select the ideal bearing steel, so that the operation of mechanical equipment is smoother and create greater value.
