METAL AND STEEL FACTORY,ISHAPORE
A METALLURGICAL UNIT DEDICATED TO DEFENCE PRODUCTION
OBJECTIVE
PROJECT
TIME PERIOD
SUBMITTED BY
NAME
ROLL NO.
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INDUSTRIAL TRAINING
MANUFACTURING OF 155 mm BOFORS BARREL
20/6/2013 -19/7/2013
AJIT PAL SINGH
10030104003
FACTORY PROFILE:
 Metal & Steel Factory Ishapore, under Ordnance Factory Board, Ministry
of Defence, Government of India, is main producer of basic Ferrous and
Non-Ferrous raw material for military Hardwar.
 MSF has facilities for steel making in the form of Electric Arc Furnace,
Ladle Furnace Vacuum Degassing & Electro steel Re-melting ensuring
production of ultra clean steel.
 A high capacity PLC controlled 2650 T Forging Press with fully integrate
an double manipulators gives shape to the products like gun-barrel &
other components of artillery and tank guns. A CNC controlled Radial
Forging Press of 1250T for each hammer can forge various section and
profiles with degree of mechanical properties.
 The factory possesses a hot rolling mill, a high precision combination
cold rolling mill for making the thin strips of ferrous and non-ferrous
material with online X-ray and mechanical gauging system.
 Precision controlled heat treatment facilities impart high mechanical
properties in the metal, making it capable of performance under
conditions of high stress.
 Quality intelligence personnel with sophisticated machinery consisting of
Ultrasonography, Chemical Testing, Computer aided Spectrographic,
Hydrogen Gas Analyser and 3D coordinator for precision dimensional
measurement etc.
LOCATION
Metal &Steel Factory, Ishapore is situated in West Bengal on the eastern
bank of river Hoogly(Ganga) at a distance of 28 Km from Netaji Subhash
Chandra Bose airport, Dumdum.
HISTORICAL BACKGROUND
The factory has its origin as a part of Gun & Shell Factory at Cassiporethen known as Foundary & Shell Factory in year 1872.
In year 1892, manufacturing of steel was taken up when open-heart
furnace was comissioned.
In year 1905, it was relocated at Ishapore and continued to function as
a part of Gun & Shell Factory, Cassipore.
In 1920, it became an indipendent unit in the family of Ordanance
Factories and had to be known as Metal and Steel Factory, Ishapore.
PRODUCTS OF MSF, ISHAPORE
:
25 mm
20 mm AMR
23mm Schilka
Cartridge Case
Ballistic Cap
Barrel
Brass Rod
Breech Block
Pinaka Tube
Steel Cone
Strip
Railway Axel
PROJECT NAME : 155mm BOFORS BARREL
CAUSE FOR CHOSING THIS PROJECT:
METAL AND STEEL FACTORY (MSF) ISHAPUR consists of two major division
ferrous and non ferrous.
Bofors barrel is one of the main product of this factory which consists all
the section or shop in MSF even the new added RFS (Radial forging
shop).
As it and its test specimen cover almost 80% of the ferrous division so I
got opportunity to know all major section briefly, which increases my
practical knowledge in various field.
WHAT IS 155mm BOFORS FH (Field
Howitzer ?
 The Bofors FH 77 is still one of the world’s most
revolutionary towed field artillery systems. It has an onmount axillary power unit (APU) that gives the system its
self-propelled capabilities and supplies power to the
hydraulically supported operations, making it easy to
handle.
 It also has the unique advantage of having a fully
integrated land navigation system that gives the
coordinates of o the gun position and automatic
alignment of barrel.
DRAWING OF BOFORS BARREL
STEEL MELTING SHOP
INPUT:
Scrap iron, iron ore, lime, coke/carbon and other element(S, P, Mo, Si etc.)
WORKING PROCESS:
 The electrodes are highly charged and scrap iron behave as a neutral.
 As a result of that electrode are produced spark(a flash of light produced due to
high potential difference.)
 For it heat is generated and reach 1550c and scrap iron melt down gradually.
After melting the material lime are added To make slag.
 To generate heat.
• The first sample is sent to the spectrographic test to know chemical composition
present in it.
•
From the report it is decided, which elements are required to transfer the scrap
iron high grade steel like Mn , Si, Mo and Cr etc.
• As per need the petroleum, coke or carbon are added to increase the ‘c%’ of the
steel.
• .The first slag out
• After that the melting material are poured to the ladle called teeming.
• The ladle is transferred to the LADLE REFINING FURNACE for re melting
and achieves 1700 c.
•
From this step it is transferred to the VACUUM DEGASSING PLANT. By
this process
H2 and other oxide gas or gas are removed from
melting metal. The concept of degassing started primarily to control
the hydrogen content in steel.
• After finishing vacuum process, the purifying molten metal is poured
to the mould.
OUTPUT:
Ingot for bofors barrel 380-460mm dia. & 2m length.
NOTE :
In SMS the furnace used is EAF i.e. Electric Arc Furnace that has a
capacity of 15 ton.
WORKING FUNCTION OF ESR FURNACE:
In ESR (Electrode slag re melting) shop the Furnace name is Resistive
Furnace, by the name we can make an idea about it the Furnace
where heat is generate due to the present of resistance.
•
This Furnace follow the formula H=I2RT.
•
Where heat generate with the help of current, which is flow
through the electrode and slag.
•
Slag act as resistance.
FORGING OPERATION
INTRODUCTION:
Forging is a manufacturing process involving the shaping of metal using localized
compressive forces. It is the process by which metal is shaped by plastic
deformation by suitably applying compressive force. Usually the compressive force
is in the form of hammer blows using a power hammer or a press.
NECESSITY OF FORGING:Forging of material serves two important purposes.
• Improves mechanical properties:
Forging can produce a piece that is stronger than an equivalent cast or machined part.
As the metal is shaped during the forging process, its internal gain deforms to follow
the general shape of the part. As a result, the gain is continuous throughout the part,
giving rise to a piece with improved strength characteristics.
• Forming the shape:
Forging is a type of forming operation. It gives the metal initial formation that will be
further machined to get the desired formation.
FORGING AT MSF,ISHAPORE
Hot forging of 155mm BOFORS gun barrel is done in two forging workshops in
Metal & Steel Factory, Ishapore.
• RFS(Radial Forging Shop)
• NGF(New Gun Forge)
RADIAL FORGING SHOP (an ultra-modern forging shop of this factory)
RAW MATERIAL :
ESR slag produced from methane having diameter 680-700mm is the end length 3m
almost. Maximum weight 7.05 ton.
PROCESS:
Here two types of forging is done they are hollow forging and radial forging.
SOLID FORGING:
• The job remains solid throughout the cross-section.
• After discharging from the furnace the material is immediately taken to the forging
machine.
HOLLOW FORGING:
The most exclusive operation of radial forging machine is to be capable of making
hollow forging.
• In case of hollow forging a mandle is attached in the boring space which is fitted
in the hammering region.
• It gives the hollow job enough support to withstand the hammering pressure.The
uniformity of the boring diameter is maintained by this process.
• The bloom is forged from temperature 110-950C to soften the metal.
• The mandle which is fitted in the boring region is not made to face such a high
temperature. To avoid this problem the inner surface of the mandle is water cooled
reducing the temperature heat about 40C
• The core region being most hot, it may attach with the mandle, so if the job is now
rotated by manipulator, there may happen twisting effects. As the mandle is
cooled, the inner surface shrinks reducing the chance of twisting.
PRODUCT: Forged barrel (length is7500mm , dia. 430 ending size, 365 initial size)
Why is it termed Radial Forging?
The word ‘radial’ comes from the word ‘radius’. After completion of forging
operation it can transfer a square bloom into a uniform cylindrical shape. This
forging process also supports hollow forging, so it is called Radial Forging.
NGF (NEW GUN FORGED) SHOP
INPUT :
Ingot or ESR slag
PROCESS :
• At first the raw material that is ingot or slag has to be transferred into
Birlic Furnaces (electric furnace ) or oil fired furnace that is WES forge II
,Bigbogi ,Tatakorf depending on the condition.
• After completing 25 or 26 hour heating cycle the raw material ingot or slag
is placed to oil pressed (2650 ton) and there partially forging process takes
place and then the partial forged material again transferred into oil
furnace for near 4-5 hour and later the material again placed to press for
final forging process .
The final product is transferred to the annealing furnace for releasing its
internal stress.
OUTPUT :
Forged barrel
GUN MACHINE SHOP
INPUT: Barrels are taken to GMS after forging to make machining operation on it.
PROCESS: The machining operation includes
Turning operation:
The forged metal contains some scales of oxides. With the help of CNC operated
turning machine these scales are removed. Moreover the forged barrel remains
eccentric. Turning operation also makes the barrel perfect cylindrical.
Boring operation:
After turning the barrel is placed to boring machine. Boring means making hollow
cavity throughout centre axis.
Two types of boring operations are done in MSF, Ishapore :
they are :
Tipping :
A hollow rod is produced after boring
Solid:
Only chips are produced after boring
Centering:
A centre is made on the centre axis to hold the barrel while boring
Parting: The parting machine cuts test pieces from two ends of the barrel.
OUTPUT:
BARREL of boring diameter 140mm and length 7061mm.
NOTE:As the BARREL is tremendous heavy with a long length, is a need to give
supports in between head tail and bottom tail. These supports are called
rests.
High fluid pressure is maintained to remove chips.
HEAT TREATMENT
Heat treatment is a process by which mechanical properties of a material
can be altered. It comprises ‘Heating ,Soaking’& ‘Cooling’.
INPUT : Barrel received from GMS
PROCESS :
OUTPUT : Heat treated barrel.
TESTS
SPECTRO TEST :
INPUT :
Small segment of metal brought from SMR shop.
PROCESS :
1.Take the sample from the SMS.
2.Before test,the samples surface is made sooth by Al oxide paper
3.Spectro test done by spectro machine, manufactured in SWITHERLAND.
OUTPUTChemical composition report of metal.
UT TEST :
INPUT- Barrel
PROCESSBefore UT test the surface is oiled.
Supply specific amount of frequency throughout barrel to identify the internal crack
graphically.
OUTPUT : UT test report.
METALOGRAPHY :
In metallography test room the following test is done :
1. Macro(10 x) magnification
2. Micro
a. NMIR(Non Metallic Inclusion Rate)
b. Grain size
Macro
1.Segregation : not homogeneous
a)Random b)Centre c)Surface or sub surface
NOT ALLOWABLE :
a)Flakes b)Crack c)But and tears
d)Sponginess e)Blow hole f)Piping
MICRO :
NMIR (Non Metallic Inclusion Rate)
1.Thin (Up to 4 micron) 2.Thick (upper then 4 micron)
TEST ROOM
VARIOUS TESTS:
1.Tensile test 2.Impact test 3.Fracture toughness test
Fatigue Pre-crack info :
Temp
: 25 c
Initial maximum stress intensity
: 27.95 MPa
Final maximum stress intensity
: 27.93 MPa
Load ratio
: 0:10
0.2 % PS
: 1008.02 Mpa
Tensile strength
: 1120.02 MPa
Notch Length
: 30.00 mm
Maximum break length
: 43.780 mm
Minimum
: 42.520 mm
PHYSICAL PROPERTIES :
Impact value
: 41 min J
Impact type
: c
Type of notch
: v notch
Depth
: 2 mm
Hardness
: 321-375 BHN
PS
: 0.20 %,950-980 MPa
R of A%
: 35 min
Fracture
: 130 MPa min at +20 c
Impact direction
: T