PRODUCT NAME :
	alloy structure steel
	STANDARD:
	GB/T3077-1999 EN10083-1 EN10083-3   ISO 683-1
	GRADE COMPARISION:
	
		
			| 
				GB | 
			
				ГОСТ | 
			
				ASTM | 
			
				BS | 
			
				JIS | 
			
				NF | 
			
				DIN | 
		
		
			| 
				40Cr | 
			
				40X | 
			
				5140 | 
			
				520M40 | 
			
				SCr440 | 
			
				42C4 | 
			
				41Cr4 | 
		
	
	ULTRASONIC STANDARD:
	GB/T6402-2008 / SEP921-84.  ASTM A388
	CHEMICAL COMPOSITION;
	
		
			| 
				C | 
			
				Si | 
			
				Mn | 
			
				P≤ | 
			
				S≤ | 
			
				Cr | 
		
		
			| 
				0.37/0.44 | 
			
				0.17/0.37 | 
			
				0.50/0.80 | 
			
				0.035 | 
			
				0.035 | 
			
				0.80/1.10 | 
		
	
HEAT TREATMENT SPECIFICATION & MECHANICAL PROPERTIES:
Critical point approximate :Ac3=780℃
Normalizing temperature :850~870℃,hardness 179~229HBS。
Cold pressing workblank softening process :
Temperature 740~760℃,soaking time 4~6h and then by 5~10℃/h cooling , cooling to ≤600℃, out furnace and air cooling .
 Quenching temperature 850℃ ±10℃, oil cooling , tempering temperature 520℃±10℃.coolant  water / oil 
DELIVERY CONDITION :
Forged and slow cooling . If need heat treatment should be indicated in contract .
DIMENSION : mm
	
		
			| 
				ROUND STEEL BAR  | 
			
				COIL ROD | 
			
				WIRE | 
			
				SQUARE/ FLAT | 
		
		
			| 
				FORGED BAR | 
			
				ROLLED BAR | 
			
				HOT ROLLED  | 
			
				COLD DRAW | 
			
				FORGED  | 
			
				ROLLED  | 
		
		
			| 
				80-650 | 
			
				16-250 | 
			
				∮5.5-20 | 
			
				∮0.2-13 | 
			
				120-800×120-800 | 
			
				5-38×44-150 10-90×60-305 | 
		
	
APPLIED RANGE:
The steel after quenched & termpered used in make bearing moderate duty and moderate speed machine parts. Such as knuckle
of automobile, back axle shaft ,and gear , shaft ,worm spline shaft , center sleeve of machine tool .
	REMARK:
	Above listed parameters and sepcification only for reference . Specific parameters according to standard. Requirments beyond standard
	will be negotiated 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 as per international, Chinese
	or industry standards, or
	based on agreements with customers.