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 : 7TH

PRODUCTS OF MSF,ISHAPORE :

20 mm AMR 23mm Schilka Cartridge Case Ballistic Cap

Barrel Brass Rod Breech Block

Pinaka Tube Steel Cone Strip

Railway Axel

ACKNOWLEGEMENTCompleting 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.

OPERATION DESCRIPTION MACHINE TOOLS REMARKS

1 Disc cutting from barrel

Discs are cut from both ends the barrel

PartingMachine

Band saw -

2 Square face parallogram

These discs are cut into strips

Power saw Saw -

3 Vertical drilling First the middle part of the specimen is located.Centre drilling is done to locate the drilling tip.

Vertical drilling machine

Drilling machine

Accuracy should be carefully maintained

4 Surface grinding

The grinding wheel rotates at high rpm,the job makes translator movements

Surface grinder

Grinding wheels

Grinding wheels may be in different shapes to do different jobs.

5 Plough grinding

This is done in a close part of the machine to avoid accidents

Plough grinder

Several grinding bars act together

-

6 Vertical milling V notch Milling machine

V shaped cutting wheel

_

7 Turning Facing TurningMachine

ObliqueTool

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 EAF,LF-VDbotton poured

Preheating of slag ingredients

(e.g CaF2,Al2O3,MgO,SiO2etc)

In static furnace soaking

temperature 6Hrs

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 the shop SMS)

Dia-min=380 & max=460mm Length=2m

**5 SMS ingot= 1ESR SLAG,

** 1ESR SLAG dimensions Dia – min= 680 & max=700mm ,Length=3m

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,ISHAPOREHot 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 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

HOLLOW FORGING

ESR slag

Pre-forging

Pre-forged block for hollow barrel

GMS(boring)

RFS

Mandle fitted inside the boring diameter

Radial forging operation

SOLID FORGING

Charging the batch type furnace with ESR slag from

Methane

Charging temperature(700-800oC),rising up to 1150oC at a

rate of 80-100oC/hour

Soaking 6-7 hours at elevated temperature

Discharging and keeping red hot materials on the roller by a

mobile charger

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.

OUTPUT-

Chemical composition report of metal.

UT TEST :

INPUT- Barrel

PROCESS-Before 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%

Macro1.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 A B C DTHIN 1 1 1 1THICK NIL NIL NIL NIL

GRAIN SIZE : 10 ASTM (American Society Of Testing Method)

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 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

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.