4320H bearing steel bar

PRODUCT NAME :Bearing steel round bar ( forged ,rolled )
STANDARD:
GB/T18254-2002 ISO683-17
GRADE COMPARISION:

ULTRASONIC STANDARD:
GB/T6402-2008 / SEP921-84. ASTM A388
CHEMICAL COMPOSITION:

MANUFACTURING TECHNIQUE:
EFA+LF+VD(ESR)+ hot forged (hot rolled )
HEAT TREATMENT SPECIFICATION AND MECHANICAL PROPERTIES:

Quenching : first time 880±20℃,second time 800±20℃,oil cooling 150~200℃,air cooling .

Metallographic structure :carburized layer is high carbon martensite , centeris low carbon martensite .

Impact test :αkv (J/cm2):≥78(8)

DELIVERY CONDITION :ANNEALED
SURFACE : BLACK / GRINDING / PEELING
DIMENSION : mm
Forged round bar :dia 80-450mm
Rolled round bar :dia 16-250mm
Coild rod : dia 5.5-20mm
Wire : dia 0.2-13mm
Rolled flat bar :thickness 5-90× width 44-300mm
Forged flat bar:thickness 120-800×width 120-800
length : forged bar free length 4-5.8M,rolled bar 5.8M. for customers special requirment, the bar length can do 20 meters long.
Tolerance on diameter of forged bar : black surface -0/+5mm, peeled surface -0/+3mm.
REMARK:
Above listed parameters and sepcification only for reference . Specific parameters according to standard. Requirments beyond standard will be negotiate by both sides .
Delivery state:normalized ,annealed, spheroidal annealed, quenched & tempered ,bright bar, cold-drawn, etc. Should be indicated in contract .
Listed specifications are only typical grades; products of required specifications can be developed/produced per international, Chinese or industry standards, or based
on agreements with customers.

Packing :
Forged bar , rolled bar and coil packing in loose . Rolled wire packing in plastic woven cloth or wooden case.
APPLIED RANGE:

Alloy carburizing steel , the surface have fairly high hardness , abrasive resitance, contact fatigue stength, meanwhile in the centre ramaining better tenacity and can bearing highly shock load . Main used for such as railway bearing etc impact resistance and stand wear and tear component.