1. International Journal of Mechanical Engineering and Technology (IJMET), ISSN 0976 –
6340(Print), ISSN 0976 – 6359(Online) Volume 4, Issue 3, May - June (2013) © IAEME
344
AUTOMATIC DESIGN OF TECHNOLOGICAL PROCESS OF
FORGING
Mirlind Bruqi Rame Likaj
Mechanical Engineering Faculty Mechanical Engineering Faculty
10000, Prishtina 10000, Prishtina
Kosova Kosova
Ahmet Shala Nexhat Qehaja
Mechanical Engineering Faculty Mechanical Engineering Faculty
10000, Prishtina 10000, Prishtina
Kosova Kosova
ABSTRACT
We can get items of different configuration from the simplest to the most complex shapes.
In order to gain an optimal technologic forging process and to avoid losses of a larger scale,
an appropriate choice of the rounding ray and of the forging inclination is needed.
So far these parameters chose by graphic and analytic methods.
Further in this paper is given the procedure of automatic calculation of these parameters by
computers.
Key words: Forging, forging inclination, rounding rays, automatization.
1. INTRODUCTION
Methods for manufacturing using forging, are mostly utilized in mass serial
production. The benefit of using forging is the minimum of discarded material and minimal
finnishing proccess using cutting or without it, and their quick assembly into machinery.
These methods of manufacturing with deformation, are applicable in different sectors of
industry, such as automotive industry, railcar industry, farming equipment, household
equipment etc.
INTERNATIONAL JOURNAL OF MECHANICAL ENGINEERING
AND TECHNOLOGY (IJMET)
ISSN 0976 – 6340 (Print)
ISSN 0976 – 6359 (Online)
Volume 4, Issue 3, May - June (2013), pp. 344-348
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2. International Journal of Mechanical Engineering and Technology (IJMET), ISSN 0976 –
6340(Print), ISSN 0976 – 6359(Online) Volume 4, Issue 3, May - June (2013) © IAEME
345
There is a large number of factors to be considered when selecting rounding rays and forging
inclination such as:
- Type of technological process,
- Type of material to be machined,
- Quality of the surface of the tool,
- Work surface of the work piece,
- Deformation temperature,
- The speed of deformation,
- Lubricant, etc.
2. FORGING INCLINATION
While building the forged parts, you should take under consideration it's geometrical
shape, because of the specifics of the forging process, selection of the correct material and
raw material, preparation of the thermal treatment, method of forging based on the mechanic-
technological properties of the part, and also the construction technology of the part in
connection with the most economical way of finishing the forging and finishing process of
the part.
Forging inclination are necessary in order to be able to extract the forged part from the
tool. They should be designed in such a manner as to allow, the extraction of the forged part
without any special extraction tool.
The angle of inclination should be proportional to the friction coefficient, and the
compression tension of the material, in the engraving of the press.
Friction force Fµ which holds the forged part in the engraving will be dependent on the
friction coefficient µ, material compression tension p, contact surfaces of the forged part in
relation to the tool and the angle of engraving coefficient, Figure 1.
Friction force is:
]daN[cospF αµµ ⋅⋅= … (1)
Where:
µ friction coefficient which depends on the type of material, temperature and the
current state of the contacting surface;
p [daN] – compression tension;
A [mm2
] – surface of contact friction.
The usage of forged inclination is as follows:
1°, 3°, 5°, 7°, 9°, 12°, 15°, or
1°, 3°, 6°, 9°, 12°, 15°.
The size of forged inclination is dependent upon the on the relation between the masses
of the hammers upper die against the bottom. If this relation is small then the angles of
inclination are small too. If the report between the upper die and bottom part is 0.05, then the
angle of inclination is α = 7° ÷ 10°. If relation is 0.03, then angles of inclination are 3° ÷ 5°.

3. International Journal of Mechanical Engineering and Technology (IJMET), ISSN 0976 –
6340(Print), ISSN 0976 – 6359(Online) Volume 4, Issue 3, May - June (2013) © IAEME
346
In practice we should take care that the forging angles be as small as possible.
Difference between inner and outer inclination should be a minimum of 2° in order to ease
the extraction of the part for cooling.
All forged inclination is standardized because the much smaller assortment of cutting
tools to be used (mills) for making the engraving.
When working on parts with over pressure, the inclination angle is 0 ÷ 1°.
Research shows that by decreasing the angle during all other similar conditions also
decreases the deformation force. Increase of the deformation force is expressed during angle
change to 5° (1° ÷ 5°). Continual increase of the angle produces a lower intensity of force
increase.
α
α
Fµ
Figure 1. Friction force during material flow on the die
If the forged inclinations are smaller then the mechanical processing goes down for
about 20%.
How to lower the forged inclination?
This can be achieved by:
- Combination of hammer forging – horizontal forging machine;
- Increasing of preparation engraving;
- Combination of hammer forging - press;
- Using of special tools for removal of angles and using of calibration;
- Intensive use of lubrication device.
In real life all these combinations are possible, that is why utilization of inclination is
still not researched enough.
Besides the methods we discussed earlier, forged inclination can also be calculated
automatically by using a computer. For this method a certain algorithm has to be devised,
which is programmed using computer Figure 2.

4. International Journal of Mechanical Engineering and Technology (IJMET), ISSN 0976 –
6340(Print), ISSN 0976 – 6359(Online) Volume 4, Issue 3, May - June (2013) © IAEME
347
Classification of forged parts according
to press forging
YE
SH<1.3h
Type 2 →
hammering
N
O YE
SH<(1.3-4)h
d)
NO Type 2 →
hammering
>YE
S
H>4h,
350
350
>
<
d
d
NO Type e
YESRelation
(6) dp<d
N
O
Type l
Relat. (c)
4 solution
YE
S
Type e
DESIGN OF THE TECHNOLOGICAL PROCESS OF FORGING
FREE FORGING DIE FORGING
Open die forging Closed die forging
Hammer forging Press forging HFM
Classification of forged parts according
to hammer forging
Group I Group II Group III Class I Class II Class III Class IV
Sg.1 Sg.2 Sg.3 Sg.4 Sg.1 Sg.2 Sg.3 Sg.1 Sg.2 Sg.3 Sg.1 Sg.2 Sg.3 Sg.1 Sg.2 Sg.3 Sg.1 Sg.1
TA TB TC A B C A B C A B C A B C A B C A B C A B C A B C A B C
Finished part Finished part
Definition of Crown volume
Determining the volume V1+V2+ … +Vi=ΣVi Vk = …
And weight
m = V ρ Determining the weight of primary
Material V0 = (Vp + Vk) (1+∇)
m0 = (1.25 ÷ 1.35)m
Determining the initial dimensions
δ = f(m,L, ∇, Machine) of the part
Df = f(D, δ)
Hf = f(H, δ) Determining the type to which the
: T = f(m, ∇) part belongs
δ = f(m, ∇, L, Machine)
For outer: Outer: R=f(m,∇)
y
x
DD −
+
=φ Inner r= f(R) a) dp<D
Inner:
y
x
dd −
+
=φ Forged inclination
DF = f(D,δ)
T = f(m, ∇) Rounding Rays b) dp>d
Rrr = f(m,∇)
Finished Parts Determining the thickness of
die S = …
Calculation of forged Parts
and volume Forged part
Gutter
C = …
Tolerance
Determining the width of
channel f(c,k) V = ΣVi
Volume of crowning Determining the height of channel
channel bridge C = 0.015 A
Determining the dimensions Determining the surface of
Of initial part the part on a horizontal plane
Determining the reduced for dmax of the part A= ( ) 2
4 maxD/π
form
Force and energy Part Maximum diameter Determining the height
Depending on machine Dmax = Hi tgα and diameter of the
part d, h
Output data Selection of crown
channel f(c,k) Operation flow
STOP
Selection of crowning machine
YES
Type a 1 → hammering
(forging is done with only one
hammering)
NO
Type b 1 → hammering
(forging is done with only one
hammering)
NO
YE
S
YE
S
NO
Type 1 → hammering
YE
S
NO
Type 2 → hammering
YE
S
NO
H≤2h
c) dp<d
H>2h
Figure 2. Algorithm for construction of forging technology

5. International Journal of Mechanical Engineering and Technology (IJMET), ISSN 0976 –
6340(Print), ISSN 0976 – 6359(Online) Volume 4, Issue 3, May - June (2013) © IAEME
348
3. CONCLUSIONS
- The development of automatic forging inclination and rounding rays, allows for
shortening of the time It takes to acquire these parameters, and also the overall
technical preparation;
- This time of automation, defines a higher productivity, lower usage of materials, better
production characteristics, lower qualification manpower, in other words all elements
which are functional, even for low serial production.
4. LITERATURE
[1] S. Kalpakjan.: Manufacturing Engineering and Technology, Practice Hill, 2006
[2] M. Roosi.: Stampaggio a caldo dei metalli, Hoepli, Milano, 1984.
[3] G. Oehler.: Lavorazione della lamiera, Tehniche Novve, Milano, 1986.
[4] A. Berruti.: Stampagio e presse, Torino, 1964.
[5] E. Bugini.: Principi per la lavorazione plastica dei metalli, Capelli, Bolgna, 1964.
[6] G. Galili.: Tehnologia Meccanica – Lovarazione plastiche, Milano, 1979.
[7] B. Musofia.: Obrada metala plasticnom deformaciom, Svjetlost, Sarajevo, 1988.
[8] Shyamsundar D. Hivarale, Prof. Dr. Dilip R. Pangavhane and Nitin H. Ambhore,
“Application of Knowledge Engineering and Computational Intelligence for Structural
Topology Optimization of Forging Connecting Rod Die”, International Journal of
Mechanical Engineering & Technology (IJMET), Volume 4, Issue 2, 2013, pp. 10 - 20,
ISSN Print: 0976 – 6340, ISSN Online: 0976 – 6359
[9] Piyush Gulati, Rajesh Kanda, JaiInder Preet Singh and Manjinder Bajwa, “Simulation
and Optimization of Material Flow Forging Defects in Automobile Component and
Remedial Measures using Deform Software”, International Journal of Mechanical
Engineering & Technology (IJMET), Volume 3, Issue 1, 2012, pp. 204 - 216, ISSN
Print: 0976 – 6340, ISSN Online: 0976 – 6359