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.