Aperçu
Welcome to HDC Manufacturing, your trusted ally for personalized metal components, boasting over a decade of specialized proficiency. Equipped with cutting-edge production facilities that house advanced 4-axis and 5-axis machining centers, HDC Manufacturing guarantees precision in every intricate detail. Our extensive expertise is fortified by cutting-edge inspection tools, including coordinate measuring machines, enabling us to provide an array of machining options, such as Usinage CNC, fonderie, forger, découpe au laser, et emboutissage de métal.
Embark on a journey into the realm of 4340 Steel Machining on our dedicated page, where we unravel the unique features and applications of this remarkable material. Recognized for its outstanding strength, toughness, and high fatigue resistance, 4340 Steel plays a pivotal role in various industries. HDC Manufacturing distinguishes itself in 4340 Steel machining, merging advanced technology with years of expertise. Our unwavering commitment to quality and precision positions us as a dependable partner for all your personalized metal part requirements.
Explore the HDC Manufacturing advantage – a convergence where innovation seamlessly intertwines with craftsmanship. Our capabilities and experience in 4340 Steel machining ensure top-notch results, precisely tailored to meet your specifications.
What is 4340 Steel?
The 4340 steel, a high-strength and tough alloy steel is well-known for its hardenability, strength and toughness. It is classified as a member of the Ni-Cr-Mo steel family and is given the designation 4340 by the AISI (American Iron and Steel Institute) SAE (Society of Automotive Engineers) standards. The quantity of nickel, chromium and molybdenum is large in such steel, which results in its excellent mechanical properties. 4340 steel has wide applications in parts or components where extra tension strength is a must, such as aerospace components, some automobile parts, or gears, shafts, and structural components. It can receive different hardness levels by heat treatment and it is normally provided as a quenched and tempered product to increase its strength and toughness. Furthermore, 4340 steel has a good fatigue resistance that endows it to superiority for the challenging applications that are under cyclic loading.
What are the Disadvantages of 4340 Steel?
The 4340 steel is mechanically strong and possesses excellent properties, however, some shortcomings are also noticeable. First and foremost, higher alloy contents, especially nickel, chromium, and molybdenum, increase the product’s cost, which is reflected in prices that affect affordability. What’s more, welding 4340 steel is difficult because it is highly hardenable and thus it needs to be preheated and post-weld heat treatment to limit the risk of cracking to a minimum. Machining also has a few issues such as tool wear and machining difficulties, mainly because of alloying elements, which require careful selection of cutting parameters as well as tools. On top of that, the corrosion resistance of 4340 grade is not perfect and hence requires more maintenance of properly painted surfaces so as to avoid corrosion in corrosive environments. These are some of the key features to consider when analyzing its applicability to different situations.
What Specification is 4340 Steel Named after?
L'acier 4340 doit son nom au système de spécifications SAE (Society of Automotive Engineers) AISI (American Iron and Steel Institute). Dans ce système, le préfixe « 43 » désigne un acier au chrome-molybdène et les chiffres « 40 » indiquent la teneur approximative en carbone en centièmes de pour cent. Par conséquent, l’acier 4340 signifie un acier au chrome-molybdène avec une teneur en carbone d’environ 0,401 TP3T. Cette convention de dénomination fournit un moyen standardisé de classer et d'identifier différents types d'acier en fonction de leur composition chimique et de leurs propriétés mécaniques.
What are the Other Names for 4340 Steel?
Mostly 4340 steel, highly regarded for its high strength, toughness, and hardenability, is known in practice with different names depending on local standards or through industry names. Alongside its AISI 4340 designation, it is also given names such as SAE 4340 in the automotive and machinery sectors. On the other hand, in European countries the steel is symbolized as 1.6565 under the EN standard. These alternate names are used to group and mark the nickel-chromium-molybdenum alloy steel and it is deployed mainly in aerospace, automotive and machinery sectors for creating parts having exceptional mechanical properties.
Chemical Composition of 4340 Steel
L'acier 4340 est classé comme acier faiblement allié, caractérisé par une trempabilité, une résistance, une ténacité, une résistance à la fatigue et une résistance au fluage élevées similaires à Acier 4140. Il est généralement utilisé pour les composants de machines des secteurs industriels soumis à une résistance à la traction plus élevée que l'acier 4140, tels que les broches, les engrenages, les broches, les accouplements, etc.
| Composant | Wt.% |
| Carbone (C) | 0,37 – 0,43 |
| Fer (Fe) | 95,195 – 96,33 |
| Chrome (Cr) | 0,70 – 0,90 |
| Manganèse (Mn) | 0,60 – 0,80 |
| Molybdène (Mo) | 0,20 – 0,30 |
| Nickel (Ni) | 1,65 – 2,0 |
| Phosphore (P) | 0,0 – 0,035 |
| Silicium (Si) | 0,15 – 0,30 |
| Soufre (S) | 0,0 – 0,04 |
L'influence de la composition élémentaire sur les performances de l'acier 4340
The performance of 4340 steel is controlled by its elemental composition, in a very narrow way. Chromium improves hardenability and corrosion resistance while molybdenum brings strength and high temperature resistance. Nickel functions as a grain refiner and tends to improve toughness and impact resistance of the material by creating forceful micro-structures during quenching. Carbon content rules hardness and strength as well and they must be well managed for the purpose of balancing the properties. Manganese hardens and helps to produce grains of uniform sizes which in turn increases toughness. Silicon is host to deoxidation and grain refinement but increases strength and oxidation resistance at the same time. These elements as a whole tune the properties of 4340 steel to a performance level that makes it suitable for wide applications in aerospace, automotive, and machine manufacturing.
Mechanical Properties of 4340 Steel
| Propriétés mécaniques | Métrique | Anglais |
| Résistance à la traction ultime | 1282 MPa | 185900 psi |
| Résistance à la traction | 862 MPa | 125000 psi |
| Allongement à la rupture | 12.2 % | 12.2 % |
| Réduction de la superficie | 36.3 % | 36.3 % |
| Dureté, Brinell | 363 | 363 |
| Dureté, Knoop | 392 | 392 |
| Dureté, Rockwell B | 100 | 100 |
| Dureté, Rockwell C | 40 | 40 |
| Dureté, Vickers | 384 | 384 |
| Module d'élasticité | 200 GPa | 29000 ksi |
| Module de masse | 159 GPa | 23100 ksi |
| Module de cisaillement | 78,0 GPa | 11300 ksi |
| Coefficient de Poisson | 0.29 | 0.29 |
| Usinabilité | 50 % | 50 % |
Physical Properties of 4340 Steel
| Propriétés physiques | Métrique | Anglais | commentaires |
| Densité | 7,85 g/cc | 0,284 lb/in² | |
| Propriétés électriques | |||
| Résistivité électrique | 0,0000248 ohm-cm | 0,0000248 ohm-cm | Température 20 °C/68,0 °F |
| 0,0000298 ohm-cm | 0,0000298 ohm-cm | Température 100 °C/212 °F | |
| 0,0000552 ohm-cm | 0,0000552 ohm-cm | Température 400 °C/752 °F | |
| 0,0000797 ohm-cm | 0,0000797 ohm-cm | Température 600 °C/1110 °F | |
| Propriétés thermiques | |||
| La capacité thermique spécifique | 0.475 J/g-°C | 0.114 BTU/lb-°F | Acier typique de la série 4000 |
| Conductivité thermique | 44.5 W/m-K | 309 BTU-in/hr-ft²-°F | Acier typique |
Equivalent Materials of 4340 Steel
| UE | FR | 34CrNiMo6 (1.6582) | ||
| Etats-Unis | – | 4340 | ||
| Allemagne | DIN,WNr | 34CrNiMo6 GS-34CrNiMo6V | ||
| Japon | JIS | SNCM447 | ||
| France | AFNOR | 35NCD6 | ||
| Angleterre | BS | 817M40 | ||
| Italie | Uni | 35CrNiMo6 35NiCrMo6KB | ||
| Chine | Go | 34CrNi3Mo 34CrNiMo ZG34CrNiMo | ||
| Suède | SS | 2541 | ||
| Pologne | PN | 34HNM | ||
| Tchéquie | CSN | 16342 16343 16444 | ||
| Russie | GOST | 36KH2N2MFA 38KH2N2MA 40KHN2MA | ||
| Inter | ISO | 36CrNiMo6 | ||
What are the Processing Challenges of 4340 Steel?
Working on 4340 steel is hard because it is hardenable with alloying elements. Machinability is another problem, especially if the material is in the hardened state because the alloying elements increase the wear of the tools, and also the cutting force. Welding is a difficult application because of cracking possibilities and therefore, a heating process before welding, post-welding heat treatment, as well as special attention to parameters are required. The setting of the heat treatment should be accurately controlled in order to prevent distortion and to achieve the proper properties. Distortion routing is the norm and typically expected during processing, which means vendors have to add fixturing and stress-release processes. Even with the difficulties, many sophisticated techniques and careful monitoring can produce high-grade and high- fitness components with the unique mechanical properties of 4340 steel.
Applications de l'acier 4340
Automobile:
- L'acier 4340 améliore les composants automobiles tels que entretoises de roue, adaptateurs, couvercles de soupapes, et jauges, garantissant une durabilité et des performances optimales.
Aérospatial:
- Dans l'aérospatiale, l'acier 4340 est crucial pour collecteurs d'échappement, roues à aubes, raccords de tuyauterie, et corps de vannes, offrant de la solidité dans des conditions de vol exigeantes.
Composants médicaux :
- Connu pour sa précision, l'acier 4340 est utilisé en médecine composants de précision et boîtiers d'alimentation des capteurs, garantissant la précision des équipements de soins de santé.
Produits personnalisés :
- L'acier 4340 polyvalent est idéal pour les produits personnalisés tels que charnières de piano, charnières à balles, et pièces BMX personnalisées, offrant force et flexibilité.
Moto:
- L'acier 4340 contribue à la résistance et à la résilience des composants de moto comme pignons, roues, protections de radiateur, et repose-pieds.
Bande-annonce:
- L'acier 4340 robuste est essentiel dans les remorques, utilisées dans coupleurs, boules d'attelage, crochets d'attelage, crics de remorque, et rampes pour la fiabilité et la sécurité.
Vélo:
- Appliqué dans les composants de vélo comme tiges, plateaux, moyeux, pédales, et pédaliersL'acier 4340 offre résistance et durabilité.
Kart :
- L'acier 4340 joue un rôle essentiel dans les composants de karting, notamment pignons, rondelles, entretoises, roulements, volants, et jantes, garantissant des performances élevées.
