Special Design for Astra Vxr Fully Forged Blocks - Forged Shaft – DHDZ

Open Die Forgings Manufacturer In China

FORGED SHAFT / STEP SHAFT/ SPINDLE / AXLE SHAFT

The application fields of forgings shaft are
Shaft forgings (mechanical components) Shaft forgings are cylindrical objects that are worn in the middle of the bearing or in the middle of the wheel or in the middle of the gear, but a few are square. A shaft is a mechanical part that supports a rotating part and rotates therewith to transmit motion, torque or bending moments. Generally, it is a metal rod shape, and each segment can have a different diameter. The parts of the machine that make the slewing movement are mounted on the shaft. Chinese name shaft forging type shaft, mandrel, drive shaft material use 1, carbon steel 35, 45, 50 and other high-quality carbon structural steel because of its high comprehensive mechanical properties, more applications, of which 45 steel is used most widely. In order to improve its mechanical properties, normalizing or quenching and tempering should be carried out. For structural shafts that are not important or have low forces, carbon structural steels such as Q235 and Q275 can be used. 2, alloy steel Alloy steel has higher mechanical properties, but the price is more expensive, mostly used for shafts with special requirements. For example, high-speed shafts using sliding bearings, commonly used low-carbon alloy structural steels such as 20Cr and 20CrMnTi, can improve the wear resistance of the journal after carburizing and quenching; the rotor shaft of the turbo generator works under high temperature, high speed and heavy load conditions. With good high temperature mechanical properties, alloy structural steels such as 40CrNi and 38CrMoAlA are often used. The blank of the shaft is preferred for forgings, followed by round steel; for larger or complex structures, cast steel or ductile iron can be considered. For example, the manufacture of a crankshaft and a camshaft from ductile iron has the advantages of low cost, good vibration absorption, low sensitivity to stress concentration, and good strength. The mechanical model of the shaft is the beam, which is mostly rotated, so its stress is usually a symmetric cycle. Possible failure modes include fatigue fracture, overload fracture, and excessive elastic deformation. Some parts with hubs are usually installed on the shaft, so most shafts should be made into stepped shafts with a large amount of machining. Structural Classification Structural Design The structural design of the shaft is an important step in determining the reasonable shape and overall structural dimensions of the shaft. It consists of the type, size and position of the part mounted on the shaft, the way the part is fixed, the nature, direction, size and distribution of the load, the type and size of the bearing, the blank of the shaft, the manufacturing and assembly process, the installation and transport, the shaft The deformation and other factors are related. The designer can design according to the specific requirements of the shaft. If necessary, several schemes can be compared to select the best design.

The following are the general shaft structure design principles

1. Save materials, reduce weight, and use equal-strength shape. Dimensional or large section coefficient cross-sectional shape.

2, easy to accurately position, stabilize, assemble, disassemble and adjust the parts on the shaft.

3. Use various structural measures to reduce stress concentration and improve strength.

4. Easy to manufacture and ensure accuracy.

Classification of shafts Common shafts can be divided into crankshafts, straight shafts, flexible shafts, solid shafts, hollow shafts, rigid shafts, and flexible shafts (flexible shafts) depending on the structural shape of the shaft.

The straight shaft can be further divided into

1 shaft, which is subjected to both bending moment and torque, and is the most common shaft in machinery, such as shafts in various speed reducers.

2 mandrel, used to support the rotating parts only to bear the bending moment without transmitting torque, some mandrel rotation, such as the axle of the railway vehicle, etc., some of the mandrel does not rotate, such as the shaft supporting the pulley.

3 Transmission shaft, mainly used to transmit torque without bending moment, such as long optical axis in crane moving mechanism, drive shaft of automobile, etc.

The material of the shaft is mainly carbon steel or alloy steel, and ductile iron or alloy cast iron can also be used. The working capacity of the shaft generally depends on the strength and stiffness, and the high speed depends on the vibration stability. Application Application Torsional stiffness The torsional stiffness of the shaft is calculated as the amount of torsional deformation of the shaft during operation, measured in terms of the torsion angle per meter of shaft length. The torsional deformation of the shaft should affect the performance and working accuracy of the machine. For example, if the torsion angle of the camshaft of the internal combustion engine is too large, it will affect the correct opening and closing time of the valve; the torsion angle of the transmission shaft of the gantry crane motion mechanism will affect the synchronism of the driving wheel; A large torsional stiffness is required for shafts that are at risk of torsional vibration and shafts in the operating system.

Technical requirements 1. Machining accuracy

1) Dimensional accuracy The dimensional accuracy of shaft parts mainly refers to the diameter and dimensional accuracy of the shaft and the dimensional accuracy of the shaft length. According to the requirements of use, the accuracy of the main journal diameter is usually IT6-IT9, and the precision journal is also up to IT5. The shaft length is usually specified as the nominal size. For each step length of the stepped shaft, the tolerance can be given according to the requirements of use.

2) Geometric accuracy Shaft parts are generally supported on the bearing by two journals. These two journals are called support journals and are also the assembly reference for the shaft. In addition to the dimensional accuracy, the geometric accuracy (roundness, cylindricity) of the supporting journal is generally required. For journals of general accuracy, the geometry error should be limited to the diameter tolerance. When the requirements are high, the tolerance values allowed should be specified on the part drawing.

3) Mutual positional accuracy The coaxiality between the mating journals (the journals of the assembled drive members) in the shaft parts relative to the support journals is a common requirement for their mutual positional accuracy. Generally, the shaft with normal precision, the matching precision with respect to the radial runout of the support journal is generally 0.01-0.03 mm, and the high-precision shaft is 0.001-0.005 mm. In addition, the mutual positional accuracy is also the coaxiality of the inner and outer cylindrical surfaces, the perpendicularity of the axially positioned end faces and the axial line, and the like. 2, surface roughness According to the precision of the machine, the speed of the operation, the surface roughness requirements of the shaft parts are also different. In general, the surface roughness Ra of the supporting journal is 0.63-0.16 μm; the surface roughness Ra of the matching journal is 2.5-0.63 μ m.

The processing technology 1, the selection of the material shaft parts of the shaft parts, Mainly based on the strength, stiffness, wear resistance and manufacturing process of the shaft, and strive for economy.

Common used material: 1045 | 4130 | 4140 | 4340 | 5120 | 8620 | 42CrMo4 | 1.7225 | 34CrAlNi7 | S355J2 | 30NiCrMo12 |22NiCrMoV |EN 1.4201 |42CrMo4

FORGED SHAFT
Large forged Shaft up to 30 T.. Forging ring tolerance typically -0/+3mm up to +10mm dependent on size.
●All Metals has the forging capabilities to produce forged ring from the following alloy types:
●Alloy steel
●Carbon steel
●Stainless steel

FORGED SHAFT CAPABILITIES

Material

MAX DIAMETER

MAX WEIGHT

Carbon, Alloy Steel

1000mm

20000 kgs

Stainless Steel

800mm

15000 kgs

Shanxi DongHuang Wind Power Flange Manufacturing Co., LTD., as an ISO registered certified forging manufacturer, guarantee that the forgings and/or bars are homogenous in quality and free of anomalies which are detrimental to the mechanical properties or machining properies of the material .

Case:
Steel Grade BS EN 42CrMo4

BS EN 42CrMo4 Alloy Steel Relevant Specifications and Equivalents

42CrMo4/1.7225

C

Mn

Si

P

S

Cr

Mo

0.38-0.45

0.60-0.90

0.40 max

0.035 max

0.035 max

0.90-1.20

0.15-0.30


BS EN 10250 Material No. DIN ASTM A29 JIS G4105 BS 970-3-1991 BS 970-1955 AS 1444 AFNOR GB
42CrMo4 1.7225 38HM 4140 SCM440 708M40 EN19A 4140 42CD4 42CrMo

The steel grade 42CrMo4

Applications
Some typical application areas for EN 1.4021
Pump- and Valve parts, Shafting, Spindels ,Piston rods, Fittings, Stirrers,Bolts,Nuts

EN 1.4021 Forged ring , Stainless Steel forgings for Slewing ring

Size: φ840 x L4050mm

Forging (Hot Work ) Practice , Heat Treatment Procedure

Forging

1093-1205℃

Annealing

778-843℃ furnace cool

Tempering

399-649℃

Normalizing

871-898℃ air cool

Austenize

815-843℃ water quench

Stress Relieve

552-663℃

Quenching

552-663℃

DIN 42CrMo4 Alloy Steel Mechanical Properties

Size Ø mm

Yield stress

Ultimate tensile Stress,

Elongation

Hardness HB

Toughness

Rp0.2,N/nn2, min.

Rm,N/nn2

A5,%, min.

KV, Joule, min.

<40

750

1000-1200

11

295-355

35 at 20ºC

40-95

650

900-1100

12

265-325

35 at 20ºC

>95

550

800-950

13

235-295

35 at 20ºC


Rm - Tensile strength (MPa) (Q +T)

≥635

Rp0.2 0.2% proof strength (MPa) (Q +T)

≥440

KV - Impact energy (J)

(Q +T)

+20°
≥63

A - Min. elongation at fracture (%)(Q +T)

≥20

Z - Reduction in cross section on fracture (%)(N+Q +T)

≥50

Brinell hardness   (HBW):   (Q +T)

≤192HB

ADDITIONAL INFORMATION
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