| Type: | Sheet |
|---|---|
| Standard: | AISI, ASTM, DIN, JIS, GB, BS |
| Composition: | Check Detailed Description |
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34CrNiMo6/ AISI 4340/ 1.6582/ Flat Bar/Steel Block/Round Bar Sncm439/ Alloy Steel
AISI 4340 Alloy Steel | 34CrNiMo6 | 1.6582 | SNCM439
Ningshing Special-Steel is the leading stockist of AISI 4340 alloy steel rounds. We have running stock of solid round bars dia.16-300mm. Annealed or Q+T condition. We can also do furthur machining as per customers' requirement.
AISI 4340 Alloy Steel is a heat treatable and low alloy steel containing chromium, nickel and molybdenum. It has high toughness and strength in the heat treated condition. It is mainly used in power transmission gears and shafts, aircraft landing gear, and other structural parts.
Dimensions
Hot Rolled Round: dia.16-300 mm
Forged Round: dia.150-1200 mm
Cold Drawn Round: dia.6-30 mm
Hot Rolled Plate: 10-150 x 2000-2300 mm
Forged Block: 150-1000 x 200-1900 mm
Delivery Condition
EAF+LF+VD, Hot Rolled or Forged or Cold Drawn, Annealed or Q+T, Black or Machined surface, UT SEP1921 Class3 C/c or D/d
Equivalence
| AISI / SAE | DIN / W.Nr | JIS | GB | |
| 4340 | 34CrNiMo6 1.6582 | SNCM439 | 40CrNiMoA | |
| Other designations that are equivalent to AISI 4340 alloy steel include the following: | ||||
| AMS 6359 | AMS 6454 | ASTM A331 (4340) | ASTM A711 | SAE J1397 (4340) |
| AMS 6409 | ASTM A29 (4340) | ASTM A506 (4340) | ASTM A752 (4340) | SAE J404 (4340) |
| AMS 6414 | ASTM A320 (L43) | ASTM A519 (4340) | ASTM A829 | SAE J412 (4340) |
| AMS 6415 | ASTM A322 (4340) | ASTM A646 (4340-7) | MIL S-5000 | |
Chemical Composition (%)
| Steel Grade | C | Si | Mn | P | S | Cr | Mo | Ni |
| 34CrNiMo6 | 0.30-0.38 | ≤ 0.40 | 0.50-0.80 | ≤ 0.035 | ≤ 0.035 | 1.30-1.70 | 0.15-0.30 | 1.30-1.70 |
| 1.6582 | ||||||||
| 4340 | 0.38-0.43 | 0.15-0.35 | 0.60-0.80 | ≤ 0.035 | ≤ 0.040 | 0.70-0.90 | 0.20-0.30 | 1.65-2.00 |
| SNCM439 | 0.36-0.43 | 0.15-0.35 | 0.60-0.90 | ≤ 0.030 | ≤ 0.030 | 0.60-1.00 | 0.15-0.30 | 1.60-2.00 |
| 40CrNiMoA | 0.37-0.44 | 0.17-0.37 | 0.50-0.80 | ≤ 0.030 | ≤ 0.030 | 0.60-0.90 | 0.15-0.25 | 1.25-1.65 |
Applications
This low-alloy steel finds many applications where high strength, plasticity required such as large and important parts requiring hardening and tempering as heavy load axle for heavy machinery, axle with diameter over 250mm for steam turbine, axle of rotor wing for helicopter, axle of turbo and turbine blade and heavy load transmission part for jet engine, fasteners and gear for crank axle. It's also used for rotor spindle and blade where temperature over 400ºC. It can be used as important part with special properties after nitriding and ultrahigh strength steel after low tempering isothermal quenching.
Mechanical Properties
| Properties | Metric | Imperial |
| Tensile strength | 745 MPa | 108000 psi |
| Yield strength | 470 MPa | 68200 psi |
| Bulk modulus (typical for steel) | 140 GPa | 20300 ksi |
| Shear modulus (typical for steel) | 80 GPa | 11600 ksi |
| Elastic modulus | 190-210 GPa | 27557-30458 ksi |
| Poisson's ratio | 0.27-0.30 | 0.27-0.30 |
| Elongation at break | 22% | 22% |
| Reduction of area | 50% | 50% |
| Hardness, Brinell | 217 | 217 |
| Hardness, Knoop (converted from Brinell hardness) | 240 | 240 |
| Hardness, Rockwell B (converted from Brinell hardness) | 95 | 95 |
| Hardness, Rockwell C (converted from Brinell hardness. Value below normal HRC range, for comparison purposes only) | 17 | 17 |
| Hardness, Vickers (converted from Brinell hardness) | 228 | 228 |
| Machinability (annealed and cold drawn. Based on 100 machinability for AISI 1212 steel.) | 50 | 50 |
Thermal Properties
| Properties | Metric | Imperial |
| Thermal expansion co-efficient (20°C/68°F, specimen oil hardened, 600°C (1110°F) temper | 12.3 µm/m°C | 6.83 µin/in°F |
| Thermal conductivity (typical steel) | 44.5 W/mK | 309 BTU in/hr.ft².°F |
Fabrication & Heat Treatment
Machinability
AISI 4340 alloy steel can be machined using all conventional techniques. Machining process can be performed in the annealed or normalized and tempered conditions.
Forming
AISI 4340 alloy steel has good ductility and formability in the annealed condition. It can be bent or formed by pressing or spinning in the annealed state.
Welding
AISI 4340 alloy steel can be welded using fusion or resistance welding methods. Preheat and post heat weld procedures are followed while welding this steel by established methods.
Heat Treatment
AISI 4340 alloy steel is heat treated at 830°C (1525°F) followed by quenching in oil.
Forging
AISI 4340 alloy steel is forged at 427 to 1233°C (1800 to 2250°F).
Cold Working
AISI 4340 alloy steel can be cold worked using all conventional methods in the annealed condition. It has high ductility.
Annealing
AISI 4340 alloy steel is annealed at 844°C (1550°F) followed by cooling the furnace.
Tempering
AISI 4340 alloy steel should be in the heat treated or normalized and heat treated condition before tempering. Tempering temperatures depend upon the desired strength level.
Hardening
AISI 4340 alloy steel can be hardened by cold working or heat treatment.
Q1: What is Ningbo Ningshing Precision Machinery Group Co., Ltd ?
A1: Ningbo Ningshing Precision Machinery Group Co., Ltd., formerly known as Ningbo Ningshing Special-Steel Group Co., Ltd., is the leading distributor of Special Steel, and also a professional mold base maker in China. Our business involves special steel trading, machining processing, mold base making, heat treatment, CNC machines manufacturing.
Q2: Are you a manufacturer or a trader?
A2: For Special Steel, we are the one of the leading distributors and service center in China. 9 warehouses with over 50,000 tons of regular stock. Our workshop has various kinds of equipments for sawing, milling, grinding, drilling etc.
For mold base, we are a professional manufacturer, with 24 sets of CNC machines, 3 axis and 5 axis, CMM for inspection. We produce medium-large sized mold base for plastic injection mold and die casting die.
Q3: How do you control the quality of steels?
A3: Firstly, we have very close and deep relationship with Chinese Prime Mills, choose supplier carefully, and regard them as the long term business partner. Based on the long term cooperation, we concentrate on special steel business and expand the market step by step. Secondly, we have own technical center which is formed by the experienced engineers and technicians whom ever worked for prime mills. We control the quality in production process, in-out warehouse.
Q4:: Which kind of processing can you do?
A4: We do machining processing like cutting, milling, grinding, turning, peeling, drilling, CNC machining. Meanwhile, we do vacuum heat treatment for die and mold.
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