24 July 2021 Ball Bearing Steel Bar
GCr9 Ball Bearing Steel Bar
GCr9 steel is a kind of high carbon chromium bearing steel with less alloy content, with good performance and widely used for ball bear manufacture. After quenching and tempering, it has high hardness, uniform structure, good wear resistance and high contact fatigue performance.
GCr9 used to make various bearing rings and rolling elements for example:
Internal combustion engines, electric locomotives, automobiles, tractors, machine tools, rolling mills, drilling machines, mining machinery, general machinery, and high-speed rotating steel for high-load mechanical transmission bearings Balls, rollers and ferrules · In addition to making balls, bearing ferrules, etc., sometimes used to make tools, such as dies and measuring tools.
GCr9 steel wear resistance and hardenability are higher than GCr6 steel, the machinability is fair, the cold strain ductility is medium, the weldability is poor, and it is more sensitive to the formation of white spots, and the heat treatment has a tendency to temper brittleness. Used to manufacture steel balls with diameters of 13.5-25.4mm, tapered rollers with diameters of 10.3-18.5mm, cylindrical rollers with diameters of 9.4-17.2 and spherical rollers with diameters of 9.2-17.1.
Chemical Composition:
| C(%) | Si(%) | Mn(%) | P(%) | S(%) | Cr(%) |
|---|---|---|---|---|---|
| C(%)(%) 1.0-1.1 | Si(%)(%) 0.15-0.35 | Mn(%)(%) 0.2-0.4 | P(%)(%) ≦0.025 | S(%)(%) ≦0.025 | Cr(%)(%) 0.9-1.2 |
Mechanical Properties:
| Yield Strength Rp0.2 (MPa) | Tensile Strength Rm (MPa) | Impact KV/Ku (J) | Elongation A (%) | Reduction in cross section on fracture Z (%) | As-Heat-Treated Condition | Brinell hardness (HBW) |
|---|---|---|---|---|---|---|
| 477 (≥) | 723 (≥) | 23 | 44 | 21 | Solution and Aging, Annealing, Ausaging, Q+T,etc | 144 |
| Temperature (°C) | Modulus of elasticity (GPa) | Mean coefficient of thermal expansion 10-6/(°C) between 20(°C) and | Thermal conductivity (W/m·°C) | Specific thermal capacity (J/kg·°C) | Specific electrical resistivity (Ω mm²/m) | Density (kg/dm³) | Poisson’s coefficient, ν |
|---|---|---|---|---|---|---|---|
| 31 | - | - | 0.14 | - | |||
| 786 | 283 | - | 41.3 | 133 | - | ||
| 753 | - | 12 | 14.2 | 112 | 441 |