Sncm431 4340 DIN1.6580 30crnimo8 Hardened Steel

• Customization: Available
• Type: Flat
• Standard: AISI, ASTM, DIN, JIS, BS
• Model NO.: SNCM431 4340 DIN1.6580 30CrNiMo8
• Technique: Hot Forged,or Hot Rolled
• Shape: Round,Flat or Square
• Surface Treatment: Black Surface, Grinded,Peeled,Milled,Polished
• Special Use: Alloy Structural Steel
• Application: Structural Steel Bar
• Size Range: Round Bar:Dia12~420mm Flat Bar:2~420 X 30~1500mm
• Smelting Process: Ef, Eaf, ESR
• Delivery Condition: Hot Rolled, Forged, Annealed,Quenched and Tempered
• Surface Condition: Black Surface, Grinded,Peeled,Milled,Polished
• Transport Package: Seaworth Packing
• Specification: Round Bar: Dia12~420mm Flat Bar: 2~420 X 30~1500mm
• Trademark: CHENGQUAN
• Origin: Huangshi, Hubei
• HS Code: 7228600000
• Production Capacity: 5000tons/Year

Product Description

Applications
Alloyed heat treatable steel with a typical tensile strength of 1100 -1300 N/mm². Used for highly stressed components, where the combination of high strength with tenaciousness is of utmost importance. High cold formability: Parts of different shape can be manufactured, a favorable fibering for stress, a very good surface condition and an high dimensional accuracy. When cold formed the smooth surface leads to an increased fatigue and vibratory strength.

All Grades Comparison

Material no.	DIN	BS	ASTM
1.6580	30CrNiMo8	823M30	4340
AFNOR	ISO	OCT	JIS
30CND8	31CrNiMo8	3KH3M3F	SNCM431

Chemical Composition(%)

Steel Grade	C	Mn	Si	P	S	Cr	Ni	Mo
30CrNiMo8	0.26-0.34	0.50-0.80	0.40 max	0.025 max	0.035 max	1.80-2.20	1.80-2.20	0.30-0.50
4340	0.38-0.43	0.60-0.80	0.15-0.35	0.035 max	0.040 max	0.70-0.90	1.65-2.00	0.20-0.30
SNCM431	0.27-0.35	0.60-0.90	0.15-0.35	0.030 max	0.030 max	0.60-1.10	1.60-2.00	0.15-0.30

Mechanical Properties(T=20°C if not differently stated)

Heat treatment state	Diameter(mm)	Rm (Mpa)	Rp0.2 (Mpa)	Fracture elongation A5 (%)	Notch impact energy ISO-V [J]	Hardness (HB)
SOFT ANNEALED	/	844 min	/	/	/	250 max
ISOTHERMAL ANNEALED	/	615-815	/	/	/	183-242
QUENCHED AND TEMPERED	16 max	880-1080	685 min	16 min	40 min	289-347
QUENCHED AND TEMPERED	16-40	930-1080	735 min	16 min	40 min	275-318
QUENCHED AND TEMPERED	40-100	880-1030	685 min	17 min	40 min	261-303
QUENCHED AND TEMPERED	100-250	785-935	635 min	18 min	35 min	233-276
QUENCHED AND TEMPERED	250-500	735-885	590 min	16 min	35 min	218-262

HEAT TREATMENT AND HOT PLASTIC DEFORMATION TEMPERATURES

-	TEMPERATURE ° C	Cooling Medium
Hot plastic deformation	850-1100	/
Normalizing	850-880	air
Soft Annealing	650-690	air
Quenching	830-860	oil
Tempering	540-660	air