Hot rolled alloy round bar, 4340/40CrNiMoA/34CrNiMo6/1.6565/SNCM439

Model Number: hot rolled round bar -7 Key Specifications/Special Features: Hot rolled alloy roundbar4340/40CrNiMoA/34CrNiMo6/1.6565/SNCM4391.Description:4340 is a 1.8% nickel - chromium - molybdenum high hardenability high tensile steel - generally supplied hardened and tempered in the tensile range of 930 - 1080 Mpa (condition U) - (Rc 28 - 36).Characterized by high strength and toughness in relatively large sections.Pre hardened and tempered 4340 can be further surface hardened by flame or induction hardening and by nitriding.4340 is used in most industry sectors for applications requiring higher tensile/yield strength than 4140 can provide.2.Applications:Components for the aircraft, automotive, general engineering industries, Propeller shafts, connecting rods, gear shafts, and other automobile parts, Heavy forgings, Rotors, shafts, discs. Pulley shafts, gears, pins and axles, Heavy-duty axles, shafts, heavyduty gears, spindles, pins, studs, collets, bolts, couplings, sprockets, pinions, torsion bars, connecting rods, crow bars, conveyor parts etc. Used where higher yield and tensile strength than 4140 is required.3.Related specifications:

Australia AS 1444-2007 4340

Germany W.Nr 1.6565 34CrNiMo6

Great Britain BS970 1955 EN24

BS970 Part 3:1991 817M40

BS EN10083:1-1991 817M40

USA ASTM A29A29M 1991 4340

ASTM A322 4340

SAE 4340

UNS G43400

Japan JIS G 4103 SNCM439

JIS G 4103 SNCM8

Werkstoff 1.6565 40NiCrMo6

4.Chemical Composition(%):

Carbon 0.37-0.44

Silicon 0.17-0.37

Manganese 0.50-0.80

Phosphorus 0.04 max

Sulphur 0.04 max

Chromium 0.60-0.90

Molybdenum 0.15-0.25

Nickel 1.25-1.85

5.Process:EAF+LF+VOD+ Rolled +Heat Treatment(optional)

6.Specification:
Dia:10-320mm
Length: as your request .

7.Surface finishes:
Black, Peeled K12, Cold Drawn, Turned & Polished H10, H11, Precision Ground H9, H8

8.Test:Ultrasonic test according to SEP 1921-84 3Cc

9.Forging:
Heat to 1150 oC - 1200 oC maximum, hold until temperature is uniform throughout the section.
Do not forge below 850 oC.
Following forging operation the work piece should be cooled as slowly as possible in sand or dry lime etc.

10.Heat Treatment
Annealing
Heat to 800 oC - 850 oC, hold until temperature is uniform throughout the section and cool in furnace.
Flame or Induction Hardening
4340 hardened and tempered bar can be further surface hardened by either the flame or induction hardening methods resulting