Metal & Steel Factory,
a
Ordnance, Ministry of Defence, Government of India
METAL AND STEEL
FACTORY,ISHAPORE
A METALLURGICAL UNIT DEDICATED TO DEFENCE PRODUCTION
OBJECTIVE : INDUSTRIAL TRAINNING
PROJECT
: MANUFACTURING OF BOFORS BARREL
TIME PERIOD : 20/6/2013 -19/7/2013
COLLEGE
: AMRAPALI INSTITUTE OF
TECHNOLOGY & SCIENCE
SUBMITTED BY :
NAME
: AJIT PAL SINGH
ROLL NO.
: 10030104003
DEPARTMENT : MECHANICAL ENGINEERING
SEMISTER
:7
TH
PRODUCTS OF MSF,ISHAPORE :
20 mm AMR
Barrel
23mm Schilka Cartridge Case
Brass Rod
Pinaka Tube
Railway Axel
Steel Cone
Ballistic Cap
Breech Block
Strip
ACKNOWLEGEMENT
Completing a task is never a one man effort. It is often the
result of valuable contribution of a number of individuals
in a direct or indirect manner that helps in achieving an
objective.
It is difficult to express in words my indebt ness to all
intellectuals whose guidance and encouragement, I
received in completing the Project Report.
I express a deep sense of gratitude to following people :
1) V.Chattopadhyay (AWM/A & HRD)
2) K.C.Santra
(JWM/T.R)
3) R.K.Jaiswara
(JWM/MR)
4) NiwasRamanujam (AWM/GMS)
Limited for his valuable guidance in giving me a start and
his timely advice and active interest in my project. His
direction, supervision and constructive criticism were
indeed a source of inspiration for me.
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 varios field.
WHAT IS 155mm BOFORS BARREL ?
The Bofors FH 77 is still one of the world’s most revolutionary towed
field artillery systems.It has an on-mount auxilllary 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.
In March 2000s it was reported that the latest version of
155mm Bofors guns would be sent to India for extensive field
trials on “no-cost,no commitment” basis in may 2000s.The
Indian defence ministry accepted Bofors Weapons systems’
offer to send the 45-calibre FH-77 BD, the towed version of
which is already in use with the Indian Army ,for trials.India
invited a number of companies to demonstrate their 155-mm
artillery ssysytem in a bid to finalise its choice to meet the
army’s requirement of about 200 more field howitzers.The
FH-77 BD 6x6 self propelled artillery system and French Giant
Industries Caesar 6x6 155mm 52-calibre system are seen as
possible altenatives to the towed weapon systems.Compared
with conventional full tracked self-propelled artillery system ,
these weapons would be cheaper to procure and maintain
and offer greater strategic mobility.
TOOL ROOM FOR MAKING TEST SPECIMEN:
In tool room there are several tools to make any sort of design from a given
sample.
Here follows a few example,
Sl.
No.
1
2
3
4
5
OPERATION
DESCRIPTION
MACHINE
TOOLS
Discs are cut
from both ends
the barrel
Square face
These discs are
parallogram
cut into strips
Vertical drilling First the middle
part of the
specimen is
located.Centre
drilling is done
to locate the
drilling tip.
Surface
The grinding
grinding
wheel rotates at
high rpm,the job
makes
translator
movements
Parting
Machine
Band saw
Power saw
Saw
Vertical
drilling
machine
Drilling
machine
Accuracy
should be
carefully
maintained
Surface
grinder
Grinding
wheels
Grinding
wheels may
be in
different
shapes to
do different
jobs.
Plough
grinding
Plough
grinder
Turning
Machine
Several
grinding
bars act
together
V shaped
cutting
wheel
Oblique
Tool
Disc cutting
from barrel
6
Vertical milling
This is done in a
close part of the
machine to
avoid accidents
V notch
7
Turning
Facing
Milling
machine
REMARKS
-
-
_
It is done to
make
specimens
Tensile test
TOOL ROOM:
In tool room there are various types of machines ,describe
below some of them in short.
1.LATHE MACHINE:
The main function of a lathe is to remove metal from a piece
of work to give it the required shape and size.This is a
accomplished by holding the workpiece securely and rigidly
on the machine and then turning it against cutting tool which
will remove metal from the workpiece in the form of chips.
BASIC COMPONENTS OF LATHE :
1.BED
2.CARRIGE
3.FEED MECHANISM
4.HEADSTOCK 5.TAILSTOCK 6.SCREW CUTTING
MECHANISM
2.DRILLING MACHINE:
In drilling machine holes may be drilled quickly and at
liwcost.The hole is generated by the rotating edge of a
cutting tol known as the drill which exerts large force on the
workpiece clamped on the table as the machine tool exerts
vertical pressure to originate a hole it is called a “drill press”.
BASIC PART OF DRILLING MACHINE :
1.BASE 2.HEAD 3.SPINDLE,QUILL AND DRILL ASSEMBLY
4.COLUMN 5.TABLE 6. SPINDLE DRIVE AND FEED
MECHANISM
GRINDING MACHINE :
Grinding is metal cutting operation performed by means of a rotating
abrasive wheel that acts as a tool.This is used to finish workpieces
which must show high quality surface.
Types of grinding:
1.Non-precision
2.Precision
PARTS OF GRINDING MACHINE :
1.BASE 2.TABLE 3.HEADSTOCK
4.TAILSTOCK 5.CFROSSFEED 6.WHEEL HEAD
MILLING MACHINE
:
A milling machine is a machine tool that remove s metal as the
workpiece is feed against a rotating multipoint cutter.The cutter
rotates at high speed and because of the multiple cutting edges it
removes metal at very fast rate.
Types of milling :
1.Universal milling machine
2.Vertical milling machine
3.Horizontal milling machine
4.Omniversal milling machine
PARTS OF MILLING MACHINE :
1.Base 2.column 3.knee
4.table
5.overhanging arm 6.Front brace 6.spindle
7.Arbour
BORING MACHINE :
To bore hole in a large and heavy parts such as engine
frames,steamengines,cylinder etc. Which are practically impossible
to hold and rotate in an engine lathe or drilling machine.By l the
fitting of simple attachment,the use of the machine can be extended
still further to include screw cutting ,turning or gear cutting.
Mainly boring machine are of two types 1.Vertical 2.Horizontal
BASIC PARTS OF BORING MACHINE :
FOR VERTICAL -1.Housing 2.Table 3.crossrail
4.Ram 5.Tool head assembly 6.Bed
FOR HORIZONTAL –
1.COLUMN BASE 2.Table 3.Saddle
4.Spindle 5.Headstock 6.Bed
SHAPER :
The shaper is a reciprocating type of machine tool intended
primarily to produce flat surfaces.These surfaces may be
horizontal ,vertical or inclined.
BASIC PARTS OF SHAPER :
1.saddle 2.Table 3.crossrail
4.Ram
5.Tool head 6.Bed
7.Elevating screw
INPUT:Scrap iron, iron ore, lime, coke/carbon and other element(S,P,Mo,Sietc)
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 sends to the spectrographic test to know
chemical composition present in it.





From the report we decide which elements are required to
transfer the scrap iron high grade steel like Mn,Si,Mo and Cr etc.
As per desire we add these and sometimes we add petroleum,
coke or carbon to increase the ‘c%’ of the steel.
Sometimes we need to attend the process OXIDATION or ‘C’
BOILING.
For oxidation we use Fe2O3 or pure OXYGEN. By it we reduced
the % of ‘C’ and ‘P’.
CHEMICAL REACTION: C + O2 = CO2/CO
 4P + 5O2 = P2O5
 The first slag out
 After that the melting material are poured to the ladle,is called
temming.
 The ladle is transfer to the LADLE REFINING FURNACE for re
melting and achieves
1700oC.
 From this step it transfers 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.
 Sooner it served many purposes for production of clean steels.
 After the finishing vacuum process, the purifying the molten
metal pouring to the mould.
OUTPUT:Ingot for bofors barrel 380-460mm dia & 2m length.
NOTE: In SMS the used furnace name is EAF means Electric Arc Furnace which
capacity is 15 ton.
 Here graphite has been using as electrode and the number of electrode
is 3.
 They are mutually adjustable to up and down.
CONSTRUCTION:
A direct arc furnace consists of heavy steel shell lined with refactory brick,
silica for and lined F/C and magnetite for basic lined F/C.
The roof of the E.A.F consists of steel roofing in which silica bricks are fixedin
position.
The direct are F/C may be charged either from the charging door which also
serves from removing slag from molten metal or from the F.C roof which is
made to lift off and swing clear of the F.C.
A few roofs can be made available at all times at the roof does not have a very
long time.Depending upon whether is it a two phase or three phase E.A.F,
three graphite electrodes are inserted through the hole in the roof into the
furnace.
Steel- melting shop chart
ELECTRODE SLAG REMELTING AND REFINING
SLAG PREPARATIONELECTRODE PREPARATION
Wieghtment of slig ingredients
As per specified composition
Preheating of slag ingredients
(e.g CaF2,Al2O3,MgO,SiO2etc)
In static furnace soaking
temperature 6Hrs
EAF,LF-VDbotton poured
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.
So here slag is made artificially. The preparation of
slag 40
Alumina= 20% Plesper= 40%
Lime= 20% Other (Mg ,Si oxide)
**For Bofors Barrel the ingot size is (which comes from
SMS)
the shop
Dia-min=380 & max=460mm Length=2m
**5 SMS ingot= 1ESR SLAG,
** 1ESR SLAG dimensions
,Length=3m
Dia – min= 680 & max=700mm
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 hated and 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 operatio.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 680700mm 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 foeging 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.
OPERATION FLOW CHART IN RFS
SOLID FORGING
Charging the batch type
furnace with ESR slag from
Methane
Charging temperature(700800oC),rising up to 1150oC at a
rate of 80-100oC/hour
Soaking 6-7 hours at elevated
temperature
HOLLOW FORGING
ESR slag
Pre-forging
Pre-forged block for hollow
barrel
GMS(boring)
RFS
Discharging and keeping red
hot materials on the roller by a
mobile charger
Mandle fitted inside the
boring diameter
Radial forging operation
Radial Forging Operation
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
BirlicFurnance (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 PF 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
Boring
Centering
Parting
Turning operation:- the forged metal contains some scales of
oxides. 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, Ichapore;
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.
 Boring is carried out by two processes EJECTOR SYSTEM
and STS SYSTEM.
 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 :
Rough machined ULTRANSONIC tested barrel received from
GMS.
Hardening
1 st tempering
Pre Heating for straitening
Straightening & hardness testing
2ndtempering & hardness testing
Test Piece parting
Test piece sent to tool room for preparation
Tensile,Charphy,NMIR and FTT
Inspection & Q A
Despatch to consignee
OUTPUT : Heat treated barrel.
TESTS
SPECTRO TEST :
INPUT :
Small segment of metal brought from SMR shop.
PROCESS :
1.Taken the sample from the SMS.
2.Beforetest,samples surface is made sooth by Aloxide paper
3.Spectro test done by spectromachine,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
c.Depth of the decar,C%
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 (Upto 4 micron)
2.Thick (upper then 4 micron)
Non Metallic Metal
Sulphide (A) Alumina (B) Silicate (c)
Oxide (D)
FOR BOFORS BARREL ALLOWABLE NMIR
NMIR
THIN
THICK
A
1
NIL
B
1
NIL
C
1
NIL
GRAIN SIZE : 10 ASTM (American Society Of Testing Method)
D
1
NIL
TEST ROOM
VARIATION OF TEST :
1.Tensile test
2.Impact test
3.Fracture toughness test
Fatigue Pre-crack info :
Temp
: 25 c
Initial maximum stess 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
Maximum break length
: 43.780 mm
Minimum
: 42.520 mm
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
DRAWING OF BOFORS BARREL
Conclusion :
Enthusiasm and motivation of work comes from the
inner heart of mankind.These virtues make human
being sound in specific subjects.In case of clearing
mechanical conceptions must know the practical uses
of what they have visualised in theroretical classes.
During my course of vocational training in MSF,
Ishapore I came across different aspects of mechanical
engineering.It gave a good oppurtunity to learn what I
have read in books.The working employees of
MSF,Ishapore are very friendly and helpful.