Final pdf report

MANUFACTURING PROCESS OF A FORGED RAILWAY WHEEEL
NAME:- SUKANTA MONDAL
CLASS :- B.M.E-IV
ROLL NO:- 001411201063
DEPARTMENT:- MECHANICAL ENGINEERING
TEACHER’S NAME:- GOUTAM POHIT

VOCATIONAL TRAINNING AT
DURGAPUR STEEL PLANT

CONTENT :-
 PLANT DESCRIPTION
 DIFFERENT TYPES OF PLANT
 FLOW CHART
 RAILWAY WHEEL
 WHEEL MANUFACTURING PROCESS
 TECHNOLOGY OF THE PRODUCTION OF RAILWAY WHEEL
 LOSSES
 DIFFERENT CONTACT AREA
 REPEATED LOADS
 MAJOR WHEEL DEFECTS
 TESTING
 BIBLIOGRAPHY

PLANT DESCRIPTION :-
 Set up in late 50’s.
 Initial annual capacity of 1 million tons of crude steel per year, the capacity of
Durgapur Steel plant (DSP) was later expanded to 1.6 million tons in the 70's.
 Enhanced the capacity of the plant to 2.088 million tons of hot metal.
 1.8 million tons crude steel .
 1.586 million tons saleable steel.
 The entire plant is covered under ISO 9001: 2000 quality management system.
 DSP’s Steel Making complex and the entire mills zone, comprising its Blooming &
Billet Mill, Merchant Mill, Skelp Mill, Section Mill and Wheel & Axle Plant, are
covered under ISO: 9002 quality assurance certification.
 Plant covering an area 6.4 km.
 It is situated at a distance of 158 km from Calcutta, It is situated on the banks of
the Damodar river.
 It is The only plant in all over India which manufacture Forge Railway Wheels for
Indian Railway

Different Types of Plant :-
 Raw Material Handling Plant
 Coak-Oven
 Sinter Plant
 Blast Furnace
 Steel Melting Shop
 Continuous Casting Plant
 Merchant Mill
 Section Mill
 Wheel & Axle Plant

Railway Wheel:-
Wheels are most critical part of rolling stock. Utmost care is taken right from the
manufacture to its last use on the trains. Wheels are most stressed components of railway
vehicles. They carry axle load of up to 25 tonnes and more. They guide the train on the
tracks through curves and switches and are subjected to constant wear process.
Different functional parts of the wheel (as shown in Fig 1
below) such as flange (4), rim (3), centre (2) or hub (1)
fulfill different task and have therefore different material
properties.
Railway wheel is high safety part and special attention is
given during production process of wheel to the
reliability, availability, and safety of the
product.
Railway wheels are usually made of unalloyed or low alloyed steels with a high degree of
purity. Tight tolerances for the single alloying elements are desired in order to assure a
low variation of material properties from heat to heat.
European standard EN 13262 defines four different steel grades which mainly consist of
up to 0.6wt% of carbon, up to 0.8 wt% of manganese and up to 0.4wt% silicon. National
and international standards such as UIC 812-3V, GOST 10791, AAR M107-84, EN
13262 define the wheel steel grades and partly their manufacturing.

Manufacturing Process:-
 STEEL MAKING PROCESS
Steel for the production of railway
wheels is melted in the electric
furnace at 3200deg F with the charge
of 250 tonnes and tapping in two
ladles. High quality characteristic of
steel is provided by the subsequent
processing at the out of furnace
complex of steel treatment. The ladles
with metal are delivered in turn to the unit furnace-ladle, where the metal finishing and
refining takes place. Steel blowing in the ladle by argon along with the refining process
provide for the sculpture content in the finished metal equal to 0.010% phosphorus –
0.015% and less, and uniform distribution of another elements. Degassing process is
affected by means of removing the hydrogen, nitrogen, oxygen dissolved in metal at the
vacuum degassing set simultaneously with argon blowing. Hydrogen content in steel is
within the limits up to 2 ppm.

 WHEEL MANUFACTURING
From electric furnace molten metal is transferred to ladle which pours
metal in graphite moulds to make ingots. Each ingot is approximately 20 feet long. Ingots
are then cut into small pieces called billets. Each weight around about 1000 pounds.
Billets are then transferred to rotary furnace where they are heated to 2400 deg F. From
other end of furnace machine transfer these billets to scaling unit where their outer most
layers are removed. After that these billets are subjected to pressure of 9000tonnes in a
press which forge these billets to rough shape of a wheel. The train wheel increases 20%
in diameter when it rolled on rolling mill. Then it goes to final shaping press where centre
hole is punched in it. After heat treatment, machine sprays cold water to harden the steel.
Wheels are machined to correct shape of rim, axle hole and imbalance checking. Various
Nondestructive tests like magnetic particle and ultrasonic tests are carried out to check
any abnormalities in the wheel. The chemical composition of steel is checked by
spectrometer. Automated brinell is used for measuring hardness.

The Technology of the Production of Railway Wheels
Open-hearth Furnace Ladle Ladle-furnace Vacuum degassing set
Notching and
breaking of ingot
into initial billets
Billets inspection
and repairing
Billets heating in the
rotary furnace
Hydroscaling of
cinder
Open forging on the
press 20MN
Closed forging on
the press 50MN
Punching on the press 100MN Wheel rolling on the
rolling mill
Wheel calibration on
the press 35/8 MN and
piercing of central hole
Intermediate cooling
and anti-flocking
isometric holding
Cooling of the
wheel in open air
Machining Wheels heating

Rim quenching Tempering in pit in
the furnaces
Adjustable cooling CNC machining,
imbalance checking
Automated non-destructive
control (ultrasonic test,
magnetic particle
inspection etc.)
Wheels inspection and
measuring, hardness
determination
Testing of mechanical
and other properties on
the samples
Storage

LOSSES:-
 Friction at rail-wheel interface is a significant parasitic energy loss.
 Although friction is desirable to ensure adequate traction & for brake condition.
 Two main region of frictional losses
DIFFERENT CONTACT AREA: -
 In wheel–rail contact, both rolling and sliding occur in the contact zone. On
straight track, the wheel tread is in contact with the rail head, but in curves the
wheel flange may be in contact with the gauge corner of the rail.
 Due to the conicity of the wheel profile, flanging results in a large sliding
motion in the contact.
 Wheel load is transmitted to the rail through a tiny contact area under high
contact stresses. This result in repeated loading above the elastic limit that
leads to plastic deformation. The depth of plastic flow depends on the
hardness of the rail and the severity of the curves.
Rail steel subjected to repeated loading can respond in 4 ways: -
 Load below elastic limit, response will be elastic.
 Load above elastic limit, then material strain harden & on subsequent application
 no plastic flow occurs—shakedown.
 Below a critical value (Plastic shakedown)—wear by low cycle fatigue.
 Above plastic shakedown limit material ductility exhausted—

 MAJOR WHEEL DEFECTS IN RAILWAY INDUSTRY: -
New designs and modern equipment have culminated in a shift in the mechanisms of
wheel damage over the last 15 years. In 1992 when the last metallurgical survey was
carried out by BR Research, about 80% of wheels were reprofiled due to thermal damage,
largely as a result of inefficient wheel slide protection (WSP) systems. The other causes
of premature wheel turning were identified as wear, including flange wear and thermal
damage caused by wheel slide and tread braking. Today it is estimated that up to 80% of
wheels are re profiled due to rolling contact fatigue (RCF), and although an increase in
total wheel life has been achieved, improvements are still sought.
The British Standard and European specifications for railway wheels describe classes of
heat treated wheels. The choice of the class of wheel to be used for any particular type of
rolling stock and service is based on the conditions to be met.
 WEAR
Wheel life depends largely on the resistance of the wheel to wear and its immunity to
tread failures caused by thermal cracking and shelling as a result of RCF.
Wear of wheels occurs on the wheel tread and flange. This can be minimized by
Correct alignment of the wheels, flange lubrication, material of wheel and rail being similar
and equipment in proper mechanical condition. Every effort should be made to avoid the
abnormal loss of tread metal caused by thermal cracking and shelling. The most effective
form of flange wear reduction is by flange lubrication, which can reduce wear by at least

six times. Where this is cost prohibitive or not practical, wear can be improved by
increasing the carbon content of the steel, and by promoting the morphology of the pearlite
microstructure by altering the quench rate. A typical wear profile is shown in Figure given
below
 HOLLOW WHEEL OR DEEP FLANGE
While the wheel moves there is constant wear on the tread
and thus the diameter of wheels at tread start reducing. Due
to which wheel flange height increases. Deep flange is
dangerous because it starts damaging fish plate, fish plate
bolts, distance blocks, points and crossings etc. Moreover,
inclination of 1 in 2.5 and 1 in 20 (1in 50 in Dubai Metro trains) practically vanishes
which results in higher friction and there is every possibility of wheels to derail on curves

for two wheels on same side cannot be suitably converted with different diameters to suit
longer outer and shorter inner rails automatically.
 RADIUS TOO SMALL AT THE ROOT OF FLANGE
Root radius in Dubai Metro trains is R15. In service radius at the root of flange is
subjected to maximum wear on curves and by snaking
effect of the wheels. When it is reduced to R13 gauge
will fit properly as shown in fig below.
Defect results in to increased friction between rail and
flanges because of reduction in taper of 1 in 2.5 given
on wheel flange which affects hauling capacity of the train besides wearing effect on the
rails also.
 THIN FLANGE
Flanges are subjected too severe side thrusts during the
run and as such the strength of the flanges ought to be
adequate to sustain all the severest side thrusts and
maintain smooth running. When they wear thin they
become weaker and there are cases when flanges could
not sustain side thrusts and broke causing mid-section accidents. Besides thin flanges cut
through the partly opened facing points due to any signal or permanent way or other
defect causing two roads under same train and serious accidents follow thereafter.

 THIN WHEEL
Wheels become thinner because of continuous wear and metal removal in wheel
profiling. Thin wheels are considered unsafe because it can further be thinned due to
hammering impact at rail joints resulting into cracks and breakages etc.
 SHARP FLANGE
Tip of the flange is not square but given the radius R10 and
R18. Flange wears sharp when continuously wheel
negotiates curves and during snaking effect of the wheels.
When top radius at the corner towards tread reduces beyond
tolerable limit (5mm in IR) is called sharp flange also
known as knife edged flange. It is highly dangerous as it mounts the rails at points and
nose and heel of the switch rails and crossing. It also mounts rail on the curves and easily
cause accidents if happens to negotiate outer rail.
 WHEEL FLAT
Jamming of brakes or seizure of wheels cause skidding of wheels continuous for some
distance thus damaging tread which wears excessively at the point of contact with rail
and becomes flat to certain length and depth. In such cases wheel starts rolling but with
unpleasant noise one like we hear on rail joints. This defect also irks passengers and add
to their discomfort. This cause hot axles, journal breakage, derailments and skidding if

allowed for long. It also causes false flanges on tread which is highly detrimental to safe
running of train
Tread Damage occurs from a number of mechanisms including severe tread braking at
high speeds or high speed slip, caused for example by faulty WSP systems or WSP
activity combined with low adhesion conditions, resulting in a heat input into the wheel
tread. This locally heated metal then quenches rapidly due to the ‘colder’ bulk material of
the wheel, which acts a heat sink. This phase is typically 20-30mm wide and 1mm deep.
This damage on the wheel tread may develop into larger cracks through rolling contact
and thermal input and must be turned out. Resistance to thermal damage can be improved
by lowering the carbon content of the steel. There are also other tread damage
mechanisms such as thermal fatigue, which is associated with tread braking, but would
generally be worn away due to the action of scraping whilst braking on the tread. Low
speed slide can induce local heating below the transformation temperature and at an
increased depth. The temperature is high enough, however, to overload the wheel due to
loss of strength as the temperature increases which leads to mechanical damage of the
wheel tread in the form of a ‘flat.
 ROLLING CONTACT FATIGUE
Rolling Contact Fatigue is the failure of the wheel tread due to cyclic fatigue. In Britain,
there are two notions of rolling contact fatigue;

a) Generally fatigue of the tread contact area due to high loads leading to shelling of the
surface, This surface breakdown can be greatly accelerated if abnormal conditions exist
and may occur under relatively light static loads.
b) Curving forces experience by the wheel will also cause rolling contact fatigue of the
wheel tread; it is generally seen off center of the tread towards the field side. This type of
rolling contact fatigue is generally associated with the low of an axle in a curve and leads
to chevron type indications on the field side of the tread, It can occasionally be seen
towards the flange root on some wheels and is attributed to the action of the high wheel
in curves.
Fatigue failures of wheels can be surface induced, where initiation is due to gross plastic
deformation of the wheel close to the running surface. This is normally due to high
loading and/or low material strength, and leads to cracks that grow some millimeters into
the wheel before deviating back to the surface and leading to small sections falling away
from the tread. This is a progression from the initial RCF crack initiation surface fatigue
failures occur below the running surface and initiate on a macroscopic defect, although
they can occur in a virtually defect free material if the stresses are too high. These defects
can typically grow to 30mm below the tread before deviating back to the surface, so
larger sections of the tread can break loose. This type of failure is therefore potentially
very serious.

 Following factors are found to be detrimental to wheel fatigue life: -
High wheel loads
High impurity levels
Small rail radius
Tensile residual stresses
Other damage mechanisms related to premature wheel tread turning are local tread
collapse; indentation damage, rim face bulging, and tread roll over.
High strength and higher carbon content are required for maximum resistance to shelling.
On the other hand, thermal cracking is minimized by lowering the carbon content. These
two causes of failure, thermal cracking and shelling, call for remedies which are the
opposites of each other.
For this reason, it is not possible to precisely specify the appropriate class of wheel for
the severity of service which develops under various conditions.
 Following five factors have an important influence on the wheel life:
• Static stress in the wheel treads
• Maximum train speed
• Braking requirements
• Track conditions
• Design and condition of equipment

 Testing:-
Testig is being carried out to check the strength, flaws & defects of railway wheels
Generally, there are two types of testing;
1) Destructive Testing
2) Non Destructive Testing
1) Destructive Testing:-
Brinell Hardness Test
Dr. J. A. Brinell invented the Brinell test in Sweden in 1900. The oldest of the hardness
test methods in common use today, the Brinell test is frequently used to determine the
hardness of forgings and castings that have a grain structure too course for Rockwell or
Vickers testing. Therefore, Brinell tests are frequently done on large parts. By varying the
test force and ball size, nearly all metals can be tested using a Brinell test. Brinell values
are considered test force independent as long as the ball size/test force relationship is the
same.
In the USA, Brinell testing is typically done on iron and steel castings using a 3000Kg
test force and a 10mm diameter carbide ball. Aluminum and other softer alloys are
frequently tested using a 500Kg test force and a 10 or 5mm carbide ball. Therefore the
typical range of Brinell testing in this country is 500 to 3000kg with 5 or 10mm carbide
balls. In Europe Brinell testing is done using a much wider range of forces and ball sizes.
It's common in Europe to perform Brinell tests on small parts using a 1mm carbide ball
and a test force as low as 1kg. These low load tests are commonly referred to as baby
Brinell tests.
METHOD
 The indenter is pressed into the sample by an accurately controlled test force.
 The force is maintained for a specific dwell time, normally 10-15 seconds.
 After the dwell time is complete, the indenter is removed leaving a round indent in the
sample.

 The size of the indent is determined optically by measuring two diagonals of the round
indent using either a portable microscope or one that is integrated with the load
application device.
 The Brinell hardness number is a function of the test force divided by the curved surface
area of the indent. The indentation is considered to be spherical with a radius equal to
half the diameter of the ball. The average of the two diagonals is used in the following
formula to calculate the Brinell hardness
Test Method Illustration
D = Ball diameter
d = impression diameter
F = load
HB = Brinell result
 Non Destructive Testing:-
a) Ultra Sonic Method
b) MPI Method
Ultra Sonic Method
Ultrasonic Testing (UT) uses high frequency sound energy to conduct examinations and
make measurements. Ultrasonic inspection can be used for flaw detection/evaluation,
dimensional measurements, material characterization, and more. To illustrate the general
inspection principle, a typical pulse/echo inspection configuration as illustrated below
will be used.

A typical UT inspection system consists of several functional units, such as the
pulser/receiver, transducer, and display devices. A pulser/receiver is an electronic device
that can produce high voltage electrical pulses. Driven by the pulser, the transducer
generates high frequency ultrasonic energy. The sound energy is introduced and
propagates through the materials in the form of waves. When there is a discontinuity
(such as a crack) in the wave path, part of the energy will be reflected back from the flaw
surface. The reflected wave signal is transformed into an electrical signal by the
transducer and is displayed on a screen. In the applet below, the reflected signal strength
is displayed versus the time from signal generation to when a echo was received. Signal
travel time can be directly related to the distance that the signal traveled. From the signal,
information about the reflector location, size, orientation and other features can
sometimes be gained.
Magnetic Particle Testing
Magnetic Particle Testing (MPT), also referred to as Magnetic Particle Inspection, is
a nondestructive examination (NDE) technique used to detect surface and slightly
subsurface flaws in most ferromagnetic materials such as iron, nickel, and cobalt, and
some of their alloys. Because it does not necessitate the degree of surface preparation
required by other nondestructive test methods, conducting MPT is relatively fast and
easy. This has made it one of the more commonly utilized NDE techniques.
MPT is a fairly simple process with two variations: Wet Magnetic Particle Testing
(WMPT) and Dry Magnetic Particle Testing (DMPT). In either one, the process begins

by running a magnetic current through the component. Any cracks or defects in the
material will interrupt the flow of current and will cause magnetism to spread out from
them. This will create a “flux leakage field” at the site of the damage.
The second step involves spreading metal particles over the component. If there are any
flaws on or near the surface, the flux leakage field will draw the particles to the damage
site. This provides a visible indication of the approximate size and shape of the flaw.
There are several benefits of MPT compared to other NDE methods. It is highly portable,
generally inexpensive, and does not need a stringent pre-cleaning operation. MPT is also
one of the best options for detecting fine, shallow surface cracks. It is fast, easy, and will
work through thin coatings. Finally, there are few limitations regarding the size/shape of
test specimens.
Despite its strengths, the method is not without its limits. The material must be
ferromagnetic. Likewise, the orientation and strength of the magnetic field is critical. The
method only detects surface and near-to-surface defects. Those further down require
alternative methods. Large currents are sometimes required to perform this method, thus
“burning” of test parts is sometimes possible. In addition, once MPT has been completed,
the component must be demagnetized, which can sometimes be difficult.

 Bibliography:-
Wheel Steel Handbook by Durgapur Steel Plant Authority
The Journal of Rail wheel interaction
The Book of Railway Engineering by PC Gupta, Carriage and Wagon inspector, HQ
Railway, New Delhi
Wikipedia, Google

CONCLUSION
 Studied and observed the manufacturing process of Forged Railway Wheel – from
raw material handling process to Dispatching to Railways.
 Observed the functioning of various Technical Process like Saw Cutter, Upsetting,
Forming, Punching, Rolling, Machining Processes.
 Observed Magnetic particle inspection and Ultrasonic testing for detection of
surface and bulk discontinuity respectively.

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