24 July 2021 Ball Bearing Steel Bar
GCr15SiMn Ball Bearing Steel Bar
GCr15SiMn steel is a high carbon, high chromium bearing steel with a higher wear resistance and hardenability than GCr15 steel.The critical quench diameter in oil is 90-110 mm (50% volume fraction martensite) 840 ° C oil quenching, 350 ° C tempered, and then light quenching, the surface hardness of up to 1096HV, hardened layer depth of up to 1mm.
Aiming at the insufficiency of the heat treatment process of the forming roller, non-martensitic transformation was carried out by pre-cooling at the thin edge to produce the tuffite or sorbite to enhance the toughness and reduce the stress, and then the whole quenching process was achieved.
GCr15SiMn wear resistance and hardenability higher than the GCr15, cold plastic deformation medium, poor weldability, sensitive to the formation of white spots, temper brittleness when heat treatment. For the manufacture of wall thickness> 12mm. Outer diameter ≥ 250mm ferrule; diameter 50.8-203.2 of the steel ball, diameter> 22mm of the roller; also can be used for other high hardness and wear resistance of other mechanical parts, such as rollers. Spiral gauge and so on
Ice-cold treatment can improve the dimensional stability of the bearing, or martensitic grade quenching to stabilize the retained austenite, to obtain high dimensional stability and high toughness. The steel is generally not recommended forging. General quenching and tempering after use.
Chemical Compostion:
| C(％) | Si(％) | Mn(％) | P(％) | S(％) | Cr(％) | Ni(％) | Mo(％) | Cu(%) |
|---|---|---|---|---|---|---|---|---|
| 0.95-1.05 | 0.45-0.75 | 0.95-1.25 | 0.025 | 0.025 | 1.40-1.65 | Max 0.30 | Max 0.10 | Max 0.25 |
Mechanical Properties:
| Proof strength Rp0.2(MPa) | Tensile strength Rm(MPa) | Impact energy KV(J) | Elongation at fracture A(%) | Reduction in cross section on fracture Z(%) | As-Heat-Treated Condition | Brinell hardness(HBW) |
|---|---|---|---|---|---|---|
| 686(≥) | 919(≥) | 11 | 14 | 44 | Solution and Aging,Annealing,Ausaging,Q+T,etc | 312 |
| Property | Density kg/dm3 | Temperature T °C/F | Specific heat J/kgK | Thermal conductivity W/mK | Electric resistance µΩ·cm | Modulus of elasticity kN/mm2 | Expansion rate |
|---|---|---|---|---|---|---|---|
| 342(≥) | 568(≥) | 41 | 23 | 24 | Solution and Aging,Annealing,Ausaging,Q+T,etc | 441 | |
| Temp. °C/°F | Creep strain limit (10000h) (Rp1,0)N/mm2 | Creep rupture strength (10000h) (Rp1,0)N/mm2 | |||||
| 528 | 857 | 923 |