PRODUCT NAME :
bearing steel

STANDARD:
GB/T18254-2002 ISO683-17
GRADE COMPARISION:

GB	ASTM	BS	JIS
G20CrNi2Mo	4320H	14	SNCM420

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

CHEMICAL COMPOSITION:

C	Si	Mn	P≤	S≤	Cr	Mo	Ni
0.17/0.23	0.15/0.40	0.40/0.70	0.03	0.03	0.35/0.65	0.20/0.30	1.60/2.00

HEAT TREATMENT SPECIFICATION:
Quenching : first time 880±20℃,second time 800±20℃,oil cooling 150～200℃,air cooling .
MECHANICAL PROPERTIES:
Metallographic structure :carburized layer is high carbon martensite , centeris low carbon martensite .
Impact test :αkv (J/cm2)：≥78(8)
DELIVERY CONDITION :
annealed
DIMENSION : mm

ROUND STEEL BAR		COIL ROD	WIRE	SQUARE/ FLAT
FORGED BAR	ROLLED BAR	HOT ROLLED	COLD DRAW	FORGED	ROLLED
100-700	16-250	∮5.5-20	∮0.2-13	120-800×120-800	5-38×44-150 10-90×60-305

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.

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:annealed, spheroidal annealed, quenched & tempered ,bright bar, cold-drawn, etc.
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.