Vocational Training

ReportOn

Casting, Forging, Heat Treatment & Machining

HEAVY ENGINEERING CORPORATION LTD.

FFP, HMBP & HMTP

Submitted By:Ashish Ranjan2012JE10136th SemesterB.Tech Mechanical Engineering

CONTENTS

Acknowledgement.................................................................................................................................3

1 Introduction...................................................................................................................................4

1.1.1 Foundry Forge Plant (FFP)............................................................................................4

1.1.2 Heavy Machine Building Plant (HMBP).......................................................................4

1.1.3 Heavy Machine Tools Plant (HMTP)............................................................................4

1.1.4 Project Division.............................................................................................................4

1.2 Customers:.............................................................................................................................4

1.3 Awards:.................................................................................................................................5

2 Foundry Forge Plant (FFP)............................................................................................................5

2.1 Introduction...........................................................................................................................5

2.1.1 Quality Objective...........................................................................................................5

2.2 Wood Working And Pattern Shop (06-07 Shop)...................................................................6

2.2.1 Introduction....................................................................................................................6

2.2.2 Various Equipment Used:..............................................................................................6

2.2.3 Colour Code used for various types of pattern:..............................................................7

2.2.4 Seasoning Section:.........................................................................................................7

2.2.5 Selection of Timber for Pattern making:........................................................................7

2.2.6 Pattern Making:..............................................................................................................7

2.2.7 Pattern Materials Types of Pattern..............................................................................8

2.2.8 Types of Core boxes Joining material........................................................................8

2.2.9 Fettling Materials:..........................................................................................................8

2.2.10 Painting and Coating:.....................................................................................................8

2.2.11 Pattern Inspection..........................................................................................................8

2.2.12 Pattern Storage...............................................................................................................9

2.3 Grey Iron Foundry (01 Shop).................................................................................................9

2.3.1 Introduction....................................................................................................................9

2.3.2 Description of equipment in various bays:.....................................................................9

2.3.3 Sand Plant:...................................................................................................................10

2.3.4 Non Ferrous section:....................................................................................................10

2.3.5 Inspection:...................................................................................................................11

2.3.6 Details of Equipment:..................................................................................................11

2.3.7 Process done to get a product (Casting).......................................................................11

2.4 Steel Foundry (02 Shop)......................................................................................................12

2.4.1 Introduction..................................................................................................................12

2.4.2 Sand Plant....................................................................................................................12

2.4.3 Process:........................................................................................................................13

2.4.4 Major products of this shop:........................................................................................16

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2.5 Fettling Shop (05 Shop).......................................................................................................16

2.6 Forge Shop (03 Shop)..........................................................................................................17

2.6.1 Light Forge Shop.........................................................................................................17

2.6.2 Medium Forge shop.....................................................................................................17

2.6.3 High Forge Shop..........................................................................................................18

2.6.4 The Accumulator Section:...........................................................................................18

2.7 Machine Shop (04 Shop).....................................................................................................18

2.7.1 Some of the unique machines of this shop are as follows:...........................................18

2.7.2 Heat Treatment arrangements:.....................................................................................19

3 Heavy Machine Building Plant....................................................................................................19

3.1 Introduction.........................................................................................................................19

3.2 Machines used in this Plant..................................................................................................20

3.2.1 Lathe Machine.............................................................................................................20

3.3 Shop 010-011.......................................................................................................................21

3.4 Shop 021-022.......................................................................................................................21

3.5 Shop 030-031 (Reduction Gear Shop).................................................................................22

3.5.1 Plant Specification:......................................................................................................22

3.5.2 Machine Tools:............................................................................................................22

3.6 Shop 041-042.......................................................................................................................22

3.6.1 Machine tools in the shop............................................................................................22

3.7 Product of HMBP plant.......................................................................................................23

4 Heavy Machine Tools Plant.........................................................................................................23

4.1 Introduction.........................................................................................................................23

4.2 Products...............................................................................................................................23

5 Reference.....................................................................................................................................24

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ACKNOWLEDGEMENT

I sincerely express my gratitude to Engineers & operators of HEC with whom I interacted for their guidance and knowledge for increasing my knowledge and understanding of an organization. I am very thankful to Mr. V.D Singh, Sr. D.G.M.( shop 03), H.L. Baitha , B. Nayak ( Junior Manager), Dinesh Kumar, K.K. Mishra & R. N. Pandit sir for providing me knowledge and guidance during my training period.

I am very thankful to the various departments In-charge and technicians for helping me to clear my concepts about the plant and providing me with required information.

I am also thankful to my group-mates Vijay Saijal, Bhushan Sharma , Umesh Prashad, Indra kumar Das for accompanying me in training period.

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1 INTRODUCTION

Heavy Engineering Corporation (HEC) is solely owned organization by Government of India, established in Ranchi in the Year 1958 & inaugurated by Pt. Jawaharlal Nehru. It is largest integrated engineering complex in the country with excellent design, engineering and manufacturing base. The Company is engaged in the manufacture and supply of capital equipment machine tools and spares needed for core sector industries.

HEC has made a valuable contribution in the development of industrial infrastructure of the country. It consists of three major manufacturing, project and consultancy service division namely:

Foundry Forge Plant Heavy Machine Building Plant Heavy Machine Tools Plant

1.1.1 Foundry Forge Plant (FFP)

FFP feeds casting & forgings to the other two plants, i.e. Heavy Machine Building Plant and Heavy Machine Tools Plant. In addition, FFP supplies heavy castings & forging to other customers. With an annual production capacity of 44,000 tonnes, plant area of 13,16,930 m2 and 76,000 tonnes of installed machinery, it is the largest foundry & forging complex in India and one of its kind in the world.

1.1.2 Heavy Machine Building Plant (HMBP)

The plant has a fenced off area of 5,70,000 m2 and a floor area of nearly 2,00,000 m2 well equipped with sophisticated machine tools and handling equipment of top quality. The unit is engaged in design and manufacture of equipment and components for steel plants, mining, mineral processing, material handling, power, cement, space research, nuclear power etc. It has an annual installed capacity of 40,000 tonnes of equipment and structures.

1.1.3 Heavy Machine Tools Plant (HMTP)

The plant covers an area of over 2,13,500 m2 is involved in the design and manufacture of medium & heavy duty CNC and conventional machine tools for railway, defence, ordnance factories, HAL, engineering sector, Space and other strategic sectors.

1.1.4 Project Division

Backed by a dedicated, committed and experienced team, this division executes turnkey projects from concept to commissioning of bulk material handling, steel plant projects, coal washers, cement plants and other sectors.

1.2 CUSTOMERS:

Major customers of HEC in India are:

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a) Steel Sectors: Sail, TISCO, Essar Steel, Jindal Steel, Usha, Ispat Industries, Mecon, Rastriya Ispat Nigam limited(RINL), Birla Technical Services.

b) Defence Sector: Ordinance factory, Indian Navy, Vikram Sarabhai Space center.c) Mining Sector: Coal India Limited, HCL, National Mineral development corporation,

Singareni Collieries Limited.d) Aluminium Sector: BALCO, NALCO.e) Power Sector: UP SEB, Bharat Heavy Electrical Limited(BHEL), DVC, NTPC.f) Other Sectors: TELCO, L&T, ONGC.

1.3 PRODUCTS:1. Steel Plant Equipment.

Blast Furnace. Steel Melting Converters. Forged Rolls

2. Mining equipments. Electric Rope Shovels (5 CuM & 10CuM) Draglines

3. Crushing Equipments. Primary Gyratory Crusher Cone Crusher Four Roll Crusher Rod Mill

4. Machine Tools. Vertical Turning & Boring Machine Lathe Roll Grinding Machine Deep Hole Boring Machine Radial Drilling Machine Planning Machine Plano Milling Machine Special Purpose Railway Machine Tools

5. Crane. EOT Cranes

6. Casting & Forging. Steel Casting Steel Forging Grey Iron Casting Non- Ferrous Castings

7. Special Equipment. Surface Wheel Lathe (conventional & CNC Version) Under Floor Wheel Lathes (conventional & CNC Version) Axle Journal Turning & Burnishing Machine

1.4 AWARDS:

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HEC has own the following awards in the past from Engineering Exports Promotion Council in reorganization of its export performance.

Year Awards

2007-08 SCOPE Award

2009 Indian Nuclear Society Award

2010 BRPSE Turnaround Award

2011 Performance Excellence Award

2012 BT Star PSU Excellence Turnaround Award

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2 FOUNDRY FORGE PLANT (FFP)

2.1 INTRODUCTION

The Foundry Forge Plant is one of the largest of its kind, spread over an area of 13,16,930 m 2. The factory is about 2km in length and 1.2 km in breadth. About 76,000 tons of machinery installed in the plant to cope with various operations efficiently. A special feature of this plant is the underground electric furnace, some measuring up to 20 m deep and 1.9 m in this plant. Casting and forging of practically any type and composition from few kg to as heavy as 100 tones pieces weight can be produced to meet the need of industries like steel, cement, ship building, electrical in the core sector, manufacture of sophisticated forging and forged rolls with latest technology from HITACHI ltd. Japan is on the anvil. The various features of FFP are:

Area of plant: 13.16 lakh m2

Total Machineries installed: 76,000MT.Various steps in which its constructions took place:1st stage: Non-ferrous, iron foundry, light forge section.2nd stage: Iron foundry, Steel Foundry, Forge shop, M/C Shop and other auxiliary units.3rd stage: 6000ton press

Year of starting of production: 1964 in iron foundry.

The FFP comprises of the following units:

1. Grey iron foundry 01 Shop2. Steel foundry 02 Shop3. Forge shop 03 Shop4. Machine shop 04 Shop5. Fettling shop 05 Shop6. Pattern Shop 06 Shop7. Pattern Storage and repair 07 Shop8. Tool and die shop 08 Shop9. Installation workshop 09 Shop10. Gas Plant 20 Shop11. Boiler house 21 Shop

2.1.1 Quality Objective

To demonstrate capability of the plant to meet customer’s requirement including functional safety, statutory regulations, ease of maintenance.

Continuous updating of knowledge base of personal with latest technologies of manufacture, through development programmes.

To control rejections and downtime to the level of

Rejection……………………3% Forging press down time……..10-12%

Machine Down time…………5-7% Furnace press down time……..12-15%

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2.2 WOOD WORKING AND PATTERN SHOP (06-07 SHOP)

2.2.1 Introduction

The pattern shop is unique of its kind in Asia. It is supposed to be the biggest in South East Asia equipped to produce both wooden and metal pattern. This shop is set up to fulfil the demand of pattern from iron and steel foundry, which is an important necessity for casting. Modern facilities like cross cutting saw, circular saw, planners, wood seasoning etc. are capable of producing various large pattern to 5000mm diameter and 3000 kg wt. It has mainly two wings:

06-Pattern shop area- 9,639 ft2

07- Repairing and storage area- 10,000 ft2

06 Shop is set up mainly for pattern making. 07 Shop, a separate building has been provided in southern side of the shop for repair of old and used pattern of core boxes etc. There are two bays meant for repair work and rest 5 bays for storing the used and new pattern, which are not used for time being.

Various types of timber used in pattern making are:

Teak ● Bansum Deodar ● Gamhar Lal Karram

At HEC, Gamhar and Deodar are used as pattern material for wooden pattern due to their easy and cheap availability & also due to their light weight. The moisture in timber is 35% to 45% which is brought down by means of seasoning by air, steam or by artificial mean. Artificial mean is faster process. After seasoning moisture content in wood is 8% to 9%.

2.2.2 Various Equipment Used:

S/N Machine 06 Shop 07 Shop Total1. Surface Planner 7 2 92. Thicknesser 6 2 83. Power Saw 1 0 14. Bend Saw 11 4 155. Wood milling Machine 4 2 66. German Lathe 1 0 18. Bench drill machine 4 1 59. Disc grinder 3 1 410. Boring machine 2 1 311. Segment cutting machine 1 0 112. Vertical milling machine 3 0 313. Centre Lathe 3 0 314. Radial drilling machine 1 0 115. Vertical turning & boring machine 1 0 1

2.2.3 Colour Code used for various types of pattern:

1. Grey Al alloy pattern2. Yellow Cu alloy pattern

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3. Red Cast iron pattern4. Green Master pattern5. Blue Cast steel pattern6. Black Core printing

2.2.4 Seasoning Section:

In this section, seasoning is done to remove excessive moisture of the timber and to maintain a correct level of it, about 8% to 10%.

2.2.4.1 Process of Removing Moisture

a. Naturalb. Artificial

a) In Natural seasoning the timber is kept open in the air and seasoning is done by water, then the timber is kept in pond. The pond water absorbs the moisture from the wood.

b) In artificial seasoning there are three process: In close chamber passing hot air. Passing steam in closed chamber. Passing a mixture of steam and hot air.

In artificial seasoning i.e. adopted in HEC, it takes 10-15 days depending upon the thickness, moisture content and the type of timber. The hot air inside the closed chamber is disturbed by means of fan. The temperature is maintained about 60- 80 oC.

2.2.5 Selection of Timber for Pattern making:

At HEC the pattern material is selected according to number of casting to be produced. There are different grades of pattern materials divided according to the properties of the material.

Grades

Number of castings Pattern Material

IV or V

1-2 pieces Any type of material

III 2-10 pieces Deodar, pine, GamharII 11-50 pieces Teak or DeodarI 50-100 pieces TeakO Above 100 Metals

2.2.6 Pattern Making:

The drawing of components whose pattern is being made is to be studied first. According to the customer specifications allowances are calculated on different scales like shrinkage, machine allowances etc.to the machine drawing to be done on a card board and then patterns are prepared with the help of different tools.

2.2.6.1 Contraction Rules/ Shrinkage Rules:

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For Grey cast iron 1% scale (10mm)For Al & Al alloy steel 2% scaleFor Carbon steel, low/ medium alloy steel 2% scaleWhite cast iron 1.5% or 2% scaleCopper base alloy Depending upon natureHigh alloy steel 2.5%

2.2.6.2 Permissible Tolerance (According to IS 1513-1971)

Size range(mm)

Wooden Pattern Metallic Pattern

Hard Soft Sand Mold

Shell Mold

Up to 50 0.5 0.8 0.4 0.2550-150 0.6 1.0 0.5 0.30150-300 0.8 1.2 0.6 0.35300-500 1.0 1.5 0.7 0.40500-800 1.2 2.0 0.9 0.50800-1200 1.5 2.5 0.9 0.601200-1800 1.8 3.0 1.0 -1800-2500 2.1 3.5 1.2 -2500-4000 2.4 4.0 1.5 -

2.2.7 Pattern Materials Types of Pattern

1. Timber 1. Single piece pattern2. Cast iron 2. Split Pattern3. Steel/Brass/Bronze/Copper/Al-alloy 3. Match plate pattern4. Plaster of paris 4. Core assembly pattern5. Wax 5. Sweep Pattern6. Epoxy resin 6. Master Pattern7. Plastic 7. Skeleton Pattern8. Form polystyrene 8. Old casting as a pattern

2.2.8 Types of Core boxes Joining material

1. Split Type 1. Glue2. Clamp type (height up to 200mm) 2. Screw3. Wedge type (from 200mm to 1m) 3. Epoxy resin4. Double wedge type (more than 1m) 4. Nuts and Bolts5. Dumping over type (for mass production)6. Cotter type (up to 200 mm height)

2.2.9 Fettling Materials:

1. Lifting strips2. Conveying strip3. Metal strip on strickle

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2.2.10 Painting and Coating:

To obtain good resistance to moisture, long storage life, it is essential that all the surface of pattern should be given suitable coating of paint or varnish by brush or spray.

2.2.10.1 Coating Materials:

1. Filter materials Acetone putty, Timber putty, French chalk2. Paint Nitrocellulose base Al paint3. Polish material Spirit + Chapra4. Metal spray

2.2.11 Pattern Inspection

After making pattern, it is time for inspection for accuracy. General procedure for inspection is:

1. Visual inspection 3. Dimensional inspection2. Stage inspection 4. Final inspection

2.2.12 Pattern Storage

Once the pattern has been used or prepared it is stored for future order or to be used by some minor repairs in storeroom. They are given specific coding for easy recovery.

2.3 GREY IRON FOUNDRY (01 SHOP)

2.3.1 Introduction

It is the mother of foundry forge plant. In this shop, casting are made with the help of molding and pattern casting. The melting section of the Grey iron foundry is equipped with 4 hot blast cupola furnace of 1200mm dia and 10 tones capacity per hour. These cupolas are connected to two air suppliers. The melting section has two crucible type induction furnace having capacity of 3 tones. The flow of molten metal is channelled into three molding sections: dry, green sand and rolls.In the core shop beside the normal sand core, oil sand and CO2 sand core can be produced. Gray iron castings up to maximum piece weight of 100 tons can be done in this section. Grey iron is widely used for molding different types of casting. Grey iron is basically eutectic alloy of Fe, graphite and Si. It has good fluidity, high damping capacity and good heat conductivity. In microstructure, it is marked by presence of flakes in matrix of ferrite, pearlite or austenite. In Grey iron foundry the following types of products are generally produced:

1. Iron casting of pieces weight up to 80 tones.2. Ingots moulds of pieces weight up to 75 tones.3. Cast rolls of various types such finite chill rods, grain rolls.

The whole grey iron foundry shop is divided into seven sections:

1. Core sections2. Light weight molding section3. Medium weight molding section4. Heavy weight molding section

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5. Maintenance section6. Sand plant7. Non-ferrous section

2.3.2 Description of equipment in various bays:

a) AB Bay:

This bay is also known as raw material section. In this bay, raw material supplied to cupola and induction furnace is stored, which is used for casting.

Equipment Present Qty. Capacity

1. E.O.T. cranes 1 2.5 tones2. E.O.T. cranes 1 8 tones3. Bracket cranes 2 200 kg

b) BC Bay:

This bay is divided into two halves. In the first half, system for supplying air to the cupola and mold drying ovens are kept and in 2nd half bay maintenance section , which perform all the maintenance work of 01 shop. In the first half, equipment present are:

1. E.O.T. cranes 12.5 tones2. Mold drying furnace: Pattern are shifted in it to remove gas of molds and core’s

moisture. It is operated by producer gas. Oil is required for charging process.

Equipment Present:

1. Drilling machine 4. Grinder2. Lathe 5. Press3. Shaper 6. Welding Requirement(only electric arc welding)

BC bay consists of 4 cupolas and two induction furnace of 3T capacity.

c) CD Bay:

Pit molding produces heavy castings. This bay is also known as melting section & is equipped with 4 cupola and an exhaust systems. Dry sand and air hardened sands are mostly used here.

d) DE Bay:

It is called medium heavy dry sand bay. Medium and heavy castings are produced by means of floor and pit molding.

e) FG Bay:

This bay is called heavy core making section. Cores are prepared by means of mold. This bay has seven producers gas operated mold and core drying furnaces.

f) GH Bay:

It is known as light green sand bay. In this section core and light castings are produced by means of box and floor molding.

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2.3.3 Sand Plant:

Sand used in various section of grey iron foundry shop is prepared in the sand plant. During preparation, the sand is first dried in sand drying machine. After that it is shifted to mixing unit. After the sand it is transported to different section by means of conveyor belt.

Sand plant is divided into six systems as follows:

i. Sand drier system 4. Green sand return systemii. Green sand preparation system 5. Dry sand preparation system

iii. New sand transport section 6. Dry sand return system

2.3.4 Non Ferrous section:

In this section, Cu-base alloys, Tin, Bronze etc. are cast to fulfil the requirement of HMBP & HMTP.

Raw materials:

Cu, Zn, Pb, Sn, Ni etc. all in pure form.

Products:

Bush, Bearing, washer, Nut, Al-machine cover

2.3.5 Inspection:

Inspection of finished product is done by means of following method:

1. Mechanical Testing2. Chemical Testing3. Visual Inspection

2.3.6 Details of Equipment:

1. Pit type crucible furnace:

There are 3 pit type crucible furnace. In this type of furnace oil feeding is done by gravity and flame is rotating to prevent the heat accumulation.

2. Sand Plant:

This section has a separate sand plant where the sand required for mold and core are prepared. The various types of sand prepared are dry sand, green sand, No-bake sand, CO 2 sand. The capacity of this sand plant is 1 ton.

3. Circular saw cutting machine:

It is used for cutting purpose only. Any type of cutting inclined, vertical, horizontal can be done by this machine.

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4. Grinding Machine5. Lathe6. Induction Furnace:

It has two crucibles. It is water cooled. Only treated water is used as coolant to prevent chocking of cooling pipe.

7. Centrifugal Casting unit:

It is mainly used for production of hollow cylindrical pipe of any Non-Ferrous metal depending on requirement of customer. At HEC maximum length of 2.2 m, outer dia 400mm and minimum inner diameter 200mm can be produced.

2.3.7 Process done to get a product (Casting)

Generally the following process are performed to obtain a product:

1. Sand preparation:Different types of sand in grey iron foundry are produced and are prepared with the help of an automatic sand preparation plant. Various types of sand prepared are CO2 sand, green sand, dry sand, no-bake sand or resin sand etc. are used according to the casting produced. For chunky and intricate casting CO2 sand is used. For light casting, there is special sand but cores are made of CO2 sand.

2. Moulding :Molding are done in molding boxes consisting of two parts cope and drag, but in case of big castings molds are prepared in pits dug in the foundry floor. Manual ramming is used for ramming green and dry sand in the molding boxes. Generally, no rammers are used in case of CO2 sand molds and resin sand molds.

3. Painting of mold:Paintings of molds are generally done by water based graphite paints. Two coats of paints are applied after drying of previous coatings. This facilitates good surface finish and prevents sand fusion. Water base zircon paints are used for big chunky castings. Some cores are painted with alcohol base zircon paints. They are dried by burning the alcohol.

4. Core making:Cores are made in core boxes. Generally cores are made by CO2 sand, however core oil sand and phenolic sand are also used for core making.

5. Core and Mold drying:Core and molds are dried in oven for 5-6 hours at 300oC. However CO2 sand are not dried in oven but their paint coatings are dried by gas burner using producer gas.

6. Melting:There are 4 cupolas for melting cast iron. One induction furnace of 2-10 ton capacity is also used for melting purpose.

7. Pouring:Lip pouring ladles are used for cast iron molten metals. In lip pouring extra care is taken for removing slag, after collecting the molten metal from the cupola.

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8. Fettling:This process is carried out in 05 shop. Risers are cut with the help of oxyacetylene flame, sands are removed by shot blasting, hydro blast. In hydro blast high pressure water is thrown on the casting, which washes out the sand. Shot blast is used to remove fused sand from the surface of the casting.

2.4 STEEL FOUNDRY (02 SHOP)

This foundry is designed mainly to fulfil the requirement of the forge shop and adjoining HMBP.

2.4.1 Introduction

Furnace Qty. CapacityElectric Arc Furnace 1 60 tonElectric Arc Furnace 2 30 tonElectric Arc Furnace 1 10 tonElectric Arc Furnace 1 5 tonInduction Furnace 1 2 ton

The electrodes are of graphite, whose length is adjustable and all the furnaces are hydraulically operated. There is one Vacuum Arc Degassing (VAD) unit of capacity 60T, one Vacuum Degassing (VD) unit of capacity 90T, which is used for purifying steel to produce ingots. The whole steel foundry shop covered an area of 43,310 m2. This shop is equipped with following equipment:

a) Two numbers of 10T/hr continuous sand mixture for production of phenolic resin sand mixture.

b) One shell core shooter for making intricate shapes.

2.4.2 Sand Plant

Sand required in molding section of steel foundry is prepared here. The various types of sand prepared here and their composition are:

a) Dry sand: d) Green sandRajmahal/silica sand 70% Return sand 72%Silica flour 10% New sand 15%Bentonite 0.3% Bentonite 4%Fire clay 10% Dextrin 1%Water 0.6% Iron oxide powder 1%Molasses 0.1% Water 7%

b) Zr- CO2 sand: e) Chemically treated bentonite:Zircon sand 45% Sand 90%New sand 50% Sodium silicate 6%Sodium silicate 5% Bentonite 3%

Water 1%c) Oil core sand:

Sand 90%

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Bentonite 3%Dextrin 1.5%Core oil 2.5%Water 2.5%Iron oxide powder 0.5%

2.4.3 Process:

2.4.3.1 Sand Preparation:Same as that of Iron foundry.

2.4.3.2 Molding:Same as that of iron foundry. Here for the opening of riser or gate, cracked core is used. It gives safety of casting and helps in easy removal of casting. It is generally used in Mg steel casting.

2.4.3.3 Painting:Same as that of Iron foundry.

2.4.3.4 Core making:Same as that of Iron foundry.

2.4.3.5 Core and mold drying:Same as that of Iron foundry.

2.4.3.6 Melting:Same as that of Iron foundry.

2.4.3.7 Pouring:In the case of steel casting bottom pouring is done. For this purpose ladle with opening at bottom is used. The flow of molten metal through the opening is controlled through a stopper. Bottom pouring is done to prevent the screening effect.

2.4.3.8 Shake out:Same as that of Iron foundry.

2.4.3.9 Fettling:Fettling is almost same as that of iron foundry. Sand plant is the most important part of any foundry because sand prepared plays important role in casting. In 02 shop, Rajmahal sand and Allahabad sand is used for molding. The sand used must be dry and must possesses certain parameters as follows:

a) Refractoriness should be high fusion.b) Grain size should be proper.c) Free from impurities.d) Must contain appropriate amount of clays etc.

2.4.3.10 Melting Section:

The melting section can also be divided into three units:

a. Charging unitb. Melting unitc. Die and pit unit (pouring unit)

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2.4.3.10.1 Charging unit:

This unit is concerned with preparation of scrap on which composition of the melt depends. In this unit the charge is mainly prepared for plane carbon steel, Alloy steel, Alloy steel and cast iron materials. Basic composition of the melt contains C, Si, Mn, P and S, which are also called primary elements.Melt is alloyed with different alloying element such as Cr,Ni,Mo,V, Ti etc. to give certain desired properties.

2.4.3.10.2 Melting Unit:

This unit is equipped with electric arc furnace of various capacities and Vacuum arc-degassing furnace.

Furnace Specification:

1) Electric Arc Furnace:a. Capacity 10T

Transformer rating 3.8Mv,50 HzElectrode dia 10”

b. Capacity 30TTransformer rating 3.8Mv,50 HzElectrode dia 14”

c. Capacity 60TTransformer rating 36 Mv,50 HzElectrode dia 10”

The Electric Arc Furnace (EAF) consists of 3 Electrodes, molten bath tapping spout, refractory brick movable roof, brick shell and a refractory lined bowl shaped vessel, water cooled in larger size. The furnace is primarily split into three sections:

Shell consists of the sidewalls and lower steel bowl. Hearth consists of the refractory that lines the lower bowl. Roof which may be refractory lined or water cooled and can be shaped as a section of a

sphere. The roof also supports the refractory delta in its centre, through which one or more graphite electrodes enter.

The EAF is powered by a 3 phase electrical system and therefore has three electrodes. Electrodes are round in section and in segments with threaded couplings, so that as the electrodes wear, new segments can be added. The arc forms between the charged material and the electrode, the charge is heated both by current passing through the charge and by the radiant energy evolved by the arc. The electrodes are automatically raised and lowered by a positioning system, which may use either electric winch hoists or hydraulic cylinders. The regulating system maintains constant current and power input during the melting of the charge, even though scrap may move under the electrodes as it melts. Since the electrodes move up and down automatically for regulation of the arc, and arc raised to allow removal of the furnace roof, large water-cooled cables connect the bus tubes with the transformer located adjacent to the furnace. To protect the transformer from heat, it is installed in a vault and is itself cooled via pumped oil exchanging heat with the plants water cooling systems, as the electrical conditions for arc furnace steelmaking are extremely stressful on the transformer.

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The furnace is built on a tilting platform so that the liquid steel can be poured into another vessel for transport. The operation of tilting the furnace to pour molten steel is called tapping.

1. Induction furnace:Capacity 5TFrequency 1000HzPower consumption 700KW

2. Ladle Furnace (60T):

This type of furnace is not used for metal melting, metal addition & degassing purpose, it is only used to reserve molten metal for pouring. Nozzle is placed in the bottom of ladle, to control molten metal flow during pouring.The ladle is fitted with a refractory lining that stops the steel vessel from suffering damage when the ladle is used to transport metal with high melting temperature. If the molten metal come in direct contact with the ladle shell, it would rapidly melt through the shell. Refractory lining materials come in many forms. Traditionally ladles used to be lined using pre-cast firebricks, however refractory concretes have tended to supress these in many countries.

Types:a) Casting ladle: It is used to pour molten metal into molds to produce casting.b) Transfer ladle: It is used to transfer a large amount of molten metal from one

process to another i.e. from primary furnace to either a holding furnace or an auto-pour unit.

c) Treatment ladle: It is used for a process to take place within the ladle to change some aspect of molten metal. A typical example being convert cast iron to ductile iron by the addition of various elements into the ladle.

3. Vacuum arc degassing:

During tapping of the steel, air bubbles are entrained into the steel where the tap stream enters the bath in the tap ladle. The quantity of air entrained into the steel increases with the increasing free fall height of the tap stream. The entrainment of a gas such as air into a falling stream of liquid steel has been the subject of a number of studies, however, a reliable prediction of the quantity of air entrained into a stream of liquid steel during tapping is difficult because of the assumptions that have to be made.

To obtain a high quality steel or metal, it is important to remove the inclusions, slag and undesirable gases which are dissolved in molten metal during melting and pouring process. The VAD is used for purification of molten metal. VAD is equipped with bottom plugs for argon bubbling. To achieve a homogeneous bath temperature and composition, the steel in the ladle is most often stirred by means of argon gas bubbling.

The refining of steel in the ladle is broadly defined here as comprising the following operations: deoxidation, desulfurization, dephosphorization, controlled additions of alloying elements and inclusion modification.

Deoxidation

The first step in the refining sequence in the ladle is usually the deoxidation of the steel with ferromanganese, ferrosilicon, silicomanganese and aluminum. There are three categories of steel deoxidation.

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a) Steel deoxidized with ferromanganese to yield 100–200 ppm dissolved oxygen; these are usually resulfurized steel grades.

b) Semi-killed steels deoxidized with:I. Si/Mn to yield 50–70 ppm dissolved oxygen,

II. Si/Mn/Al to yield 25–40 ppm dissolved oxygen,III. Si/Mn/Ca to yield 15–20 ppm dissolved oxygen.

c) Killed steels deoxidized with aluminum to yield 2–4 ppm dissolved oxygen.

4. Vacuum degassing:

Vacuum degassing of steel has an even longer history than the treatment of steel with calcium, initially, vacuum degassing was used primarily for hydrogen removal. However, during the last twenty years or so there has been an increased use of vacuum degassing for the production of ultralow-carbon (ULC) steels with carbon contents of 30 ppm or less. Furthermore, a relatively new family of steel grades, the so-called interstitial-free (IF) steels with carbon and nitrogen contents of 30 ppm or less, has appeared on the scene. To achieve these low carbon and nitrogen contents, a treatment under vacuum is mandatory. Presently, almost every high-quality steel producer has installed a vacuum treatment facility.

2.4.3.10.3 Pouring Unit:

After liquid metal has been prepared, it is taken to the prepared mold boxes or ingot mold with the help of ladle using E.O.T. to the molding unit or pit-casting unit. The metal is poured and allowed to solidify. The mold after solidification of casting is broken and the product is sent for further processes to carry out such as fettling, forging, heat treatment etc.

2.4.4 Major products of this shop:

Ladles for steel plants ● Sand channel Casting of tank bodies ● Stopper body Cotter pillar frames ● Steel plant equipment Excavator ● Cement plant equipment Gears ● Power plant equipment Pulleys ● Drag line items Crushing balls ● Ingots Bottom housing ● Austenitic Manganese steel items

2.5 FETTLING SHOP (05 SHOP)

It is separate shop well connected by railway track with all the production units of plants and is situated side of grey iron and steel foundry, well equipped with conventional method of shot blasting, chiselling, grinding. Built up on area of 16600m2, this shop has complete facility for heat treatment of different casting. There are in all, 11 gas fired annealing furnaces ranging from 3272 m2 and capable of being heated up to 1100 oC. There are two cooling chambers provided for rapid cooling by air blowing. This shop is divided into 9 bays, among these bays bay no.1 and 2 is under grey iron foundry control whereas all other are under steel foundry. Following are the steps for finishing the casting:

a) After shake out of the casting, the sand lumps are removed. It is done in two ways:

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i. For small casting operations performed are manually and is done by wire brush, chisel, chipping, hammer etc.

ii. For huge amount adhere sand and large castings hydro-blast, shot blast, vibrators are used.

b) Cutting of fins, parting line flash, pads, gates and unwanted projections of castings are removed by:

i. Oxy acetylene gas cuttingii. Fatal arcing

iii. Chippingiv. Grinding etc.

c) Removal of riserPreheating is done before cutting the riser to eliminate the cracking of the casting. But in case of Austenite Mn-Steel, the cutting will be done in cold condition and the temperature of the cutting zone should not exceed 1000 oC, otherwise crack will develop. Before cutting the riser of these steels, casting is preheated at 1050 oC -1100 oC and quenched into water.

d) Rough finishing of the casting is done after riser cutting. It is done by grinding, rotary tools etc.

e) Finishing of casting is done by brushing, polishing, painting etc. For grey iron foundry flogging process does the removal of gating system and risers. Here are 4 hydro blasting machines.

Cast iron castings required very less heat treatment, but steel castings needs heat treatment cycle, which depends upon size, shape and type of casting.

2.6 FORGE SHOP (03 SHOP)

Located in between the steel foundry and machine shop. This shop covers a floor area of 5000m2. The entire forge shop is divided into 3 sub divisions.

1. Light Forge shop2. Medium forge shop3. Heavy forge shop

2.6.1 Light Forge Shop

In this shop job of weight less than 500 kg are forged. The forging arrangement includes:

i. 3T pneumatic hammer 1ii. 1.6T pneumatic hammer 1

iii. 25T Pneumatic die forging unit 1iv. Trimming die forging unit 1v. 800T Horizontal forging machine 2

For handling the job while forging a manipulator is used. There is also heat treatment arrangement, low frequency induction hardening machine and quenching arrangement in the shop.

2.6.2 Medium Forge shop

Here job of 5T-10T are forged. The forging equipment includes:

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i. Hydraulic Press (3Pc)a. Capacity 1000T

Type Single cylinderb. Capacity 1650T

Type 3 cylinder & 3 stagedc. Capacity 2650T

Type 3 cylinder & 3 staged

ii. Gas Cutting machine

2.6.3 High Forge Shop

In this shop job weighing more than 10T are forged. The forging equipment consists of a very special 6000T capacity hydraulic press. The jobs are held by their heads in a special 250T crane while forging. Apart from all that, there is an electric manipulator for handling smaller jobs. There are producer gas fired bogie type furnaces for preheating the jobs before the forging. But due to unavailability of coal Hybrid furnace is being used in HEC, in which LPG and HSD (High speed diesel) fuel is used for heating the job.

2.6.4 The Accumulator Section:

The presses installed in the forging shops are supplied with their working fluid at their respective working pressure by the accumulator station built in between the MFS and HFS. The pressure of emulsion provided by the station to HFS is 350 atm and to the MFS is 250 atm.The Accumulator station consists of two parts:

a. Water purification and pre-treatment section.b. Energizing section.

2.7 MACHINE SHOP (04 SHOP)

This shop consists of automatic machine tools for finishing the jobs sent out by the foundries (01 & 02 shops) and the forging shop. There are several general purpose machine and giant center lathes, Vertical turning & Boring machine, Milling machine, Roll grinding machine, Shapers, Planners, Drilling machines etc. for handling smaller and larger jobs.

2.7.1 Some of the unique machines of this shop are as follows:

1. HEC inbuilt Horizontal Trepanning MachineTrepanning diameter range 50mm-250mmSolid drill diameter range 25mm-45mmSize range of boring head available 50mm-350mmMaximum trepanning length 20m

2. Giant center LatheSwing over bed 2080mmSwing over carriage 1700mmMaximum length of job 40mMaximum Trepanning length 24m

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Maximum weight of job 28T

3. Vertical turning and Boring MachineOperations- Turning, Boring, Tapering etc.

4. Roll Grinding MachineMaximum job diameter 800mmMaximum job length 9mMaximum job weight 800T

5. Horizontal Boring MachineMaximum job diameter 200mmMaximum job length 8000mmVertical movement 3150mmOperations- Boring, centre making, key cutting, threading, tapper cutting, groove cutting, facing etc.

6. Planner machine

2.7.2 Heat Treatment arrangements:

There are several electric and non-electric furnaces for the heat treatment of jobs like rolls, crankshafts etc. after rough machining. Some of the furnaces are as follows:

1. Medium Frequency Induction Hardening Machine:Job length 1-6mDiameter 150-800mmWeight 15TPower input 600kW

2. Low Frequency Induction Hardening Machine:Job length 5mDiameter 300-650mmWeight 15TPower input 100kW

3. Nitriding Furnace:The furnace is operated at 530-540 oC. Prolong heating is done at this temperature (50hr). Cracked ammonia gas is used as nitriding agent. The maximum case depth is achieved about 5mm in 50 litre. Six jobs can be treated at a time.

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3 HEAVY MACHINE BUILDING PLANT

3.1 INTRODUCTIONThe HMBP consists of following shops:

1. Shop 010-011 Main processes: Turning, Boring, Facing, Grinding, Vertical milling, Grooving,

Threading, Parting, Slotting Production- Crushers, slab billets, other planer products

2. Shop 020-021 Main processes: Turning, Boring, Facing, Grinding, Vertical milling, Grooving,

Threading, Parting, Slotting Production- Slab billets, Excavator

3. Shop 030-031 Main processes: Milling, Hobbing, Grinding, Turning, Boring, Slotting Production: All types of gears

4. Shop 041-042 Main Processes: CNC gas cutting sheet metal working, Welding, Sheet rolling &

punching, Planning Production: Fabrication assembled parts and components sheet metal works

5. Shop 043-044 Main Processes: Planning, Turning, Boring, Tapering, Slotting, Grinding, Threading Production: Assembled machine components after Machining as per requirement.

3.2 MACHINES USED IN THIS PLANT

3.2.1 Lathe Machine

The lathe is a machine tool which holds the job between two rigid and strong supports called centers or in a chuck or face plate which revolves. The cutting tool is rigidly held and supported in a tool post which is fed against the revolving work. The normal cutting operations are performed with the cutting tool fed either parallel or at right angles to the axis of the work. The cutting tool may also be fed at an angle relative to the axis of work for machining tapers and angles

3.2.1.1 Construction :

The main parts of the lathe are the bed, headstock, quick changing gear box, carriage and tailstock.

1) Bed: The bed is a heavy, rugged casting in which are mounted the working parts of the lathe. It carries the headstock and tail stock for supporting the job and provides a base for the movement of carriage assembly which carries the tool.

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2) Legs: The legs carry the entire load of machine and are firmly secured to floor by foundation bolts.

3) Headstock: The headstock is clamped on the left hand side of the bed and it serves as housing for the driving pulleys, back gears, headstock spindle, live centre and the feed reverse gear. The headstock spindle is a hollow cylindrical shaft that provides a drive from the motor to work holding devices.

4) Gear Box: The quick-change gear-box is placed below the headstock and contains a number of different sized gears.

5) Carriage: The carriage is located between the headstock and tailstock and serves the purpose of supporting, guiding and feeding the tool against the job during operation. The main parts of carriage are:

a. The saddle is an H-shaped casting mounted on the top of lathe ways. It provides support to cross-slide, compound rest and tool post.

b. The cross slide is mounted on the top of saddle, and it provides a mounted or automatic cross movement for the cutting tool.

c. The compound rest is fitted on the top of cross slide and is used to support the tool post and the cutting tool.

d. The tool post is mounted on the compound rest, and it rigidly clamps the cutting tool or tool holder at the proper height relative to the work centre line.

e. The apron is fastened to the saddle and it houses the gears, clutches and levers required to move the carriage or cross slide. The engagement of split nut lever and the automatic feed lever at the same time is prevented she carriage along the lathe bed.

f. Tailstock: The tailstock is a movable casting located opposite the headstock on the ways of the bed. The tailstock can slide along the bed to accommodate different lengths of job between the centers. A tailstock clamp is provided to lock the tailstock at any desired position. The tailstock spindle has an internal taper to hold the dead centre and the tapered shank tools such as reamers and drills.

3.2.1.2  Lathe Operation

The engine lathe is an accurate and versatile machine on which many operations can be performed. These operations are:

1. Plain Turning and Step Turning 8. Threading2. Facing 9. Forming3. Parting 10. Chamfering4. Drilling 11. Filling and Polishing5. Reaming 12. Grooving

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6. Boring 13. Taper Turning7. Knurling

3.3 SHOP 010-011

1. Horizontal boring machine (M/C -1191)Maximum Spindle diameter 320mmMaximum Spindle travel 2.5mMaximum Head travel 5mX direction movement 8mFeed rate 1-1.5mm/mTable can be adjusted in 360 o rotationOperations: Drilling, Boring, Facing, Turning etc.

2. Vertical Turning & Boring machine (M/C No.1192)Maximum job diameter 6300mmMaximum job Height 3200mm

3. CNC Vertical Turning & Boring machine (M/C No.1262)Maximum job diameter 14000mmMaximum job height 4700mmMaximum weight of job 250T

Manually & automated 3 Axis control Except shaping, slotting, planning all operation of lathe can be done.

4. Plano-Milling machine(M/C no.1170)Table dimension 1800mm * 6000mmMaximum height of job 1920mmMaximum weight of job 14T

3.4 SHOP 021-022

Same type of machines which are available in Shop 011 are present in this shop. In this shop medium weight type job is machined.

Some other machines which are available in this shop are:

1. Drill MachineMaximum bore diameter 80mmColumn Height 2mOperations- Rimming, Drilling, Taping, Threading

2. Slotter Machine

3. Shaper Machine

3.5 SHOP 030-031 (REDUCTION GEAR SHOP)

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3.5.1 Plant Specification:1. Building area 8760m2

2. No. of machine tools 663. No. of unique machine tools 154. Maximum Plano-Milling capacity 8.5m * 2.5m * 25m5. Maximum gear hobbing capacity 5.8m dia * 30 module6. Induction hardening capacity maxm 5m(length) * 4m (dia)

3.5.2 Machine Tools:

1. Gear Hobbing Machine(Vertical & Horizontal)2. Gear shapper Machine3. Plano-Milling Machine4. Planner Machine5. Milling Machine (Horizontal & vertical)6. Lathe(Caption, Turret, Center )

3.6 SHOP 041-042

In this shop sheet metal, fabrication and assembly of machine work is done.

3.6.1 Machine tools in the shop1. CNC Flame Cutting

Oxy-acetylene gas is used for cutting 8-500mm thick job can be cut 5 nozzle Cutting bed dimension- 6500mm * 25000mm

2. Shearing Machine(1Pc)Sheet metal is being cut by machine by shearing process. It can cut from 1mm to 6mm thickness. Maximum available shearing machine can cut up to thickness of 12mm. Cutting tool is operated by Pneumatic.

3. Roller Straightening machineThis machine is used to straight the bended plate.

4. Radial Drilling Machine

5. Punching Machine

6. Bending Roll MachineThis machine is used to bend the plate into cylindrical shape.

Welding and fabrication is also done in this shop. Mainly Submerged arc welding, MIG welding is done.

3.7 PRODUCT OF HMBP PLANT

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1. EOT Cranes :

HEC designs and manufacture heavy duty Electric Overhead Travelling cranes for application in steel plants, Engineering sector, Space research application etc. The highest capacity crane designed and manufacture so far is the 450T ladle crane to handle hot liquid metal.

2. Mining Equipment

HEC pioneered the manufacture of heavy duty mining equipment in india and has supplied over 260000T of equipment & components. Mining equipment supplied includes:

a) Power shovel 5CuM10CuM12.5CuM

b) Walking Dragline: HEC is the first Indian company to manufacture a walking dragline of 24 CuM bucket capacity with 96m boom.

c) Crushers: A wide variety of crushing & grinding equipment is offered to meet the requirements of ferrous and non-ferrous ore processing plants, cement, fertilizers, chemical and coal Industries.Types of crushers:

Gyratory crusher ● Two roll crusher Cone crusher ● Single roll crusher Jaw crusher ● Four roll crusher Reversible hammer mill ● Rod mill etc.

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4 HEAVY MACHINE TOOLS PLANT

4.1 INTRODUCTION

HEC manufactures machine tools in the heavier range that serve vital industries such as steel, Railways, engineering, mining, defence, general workshops, space research & application etc. HEC offers high precision machine tools of state of art design. In addition to the manufacturing new machine tools, HEC also provides refurbishment and rebuilding services.

HMTP consists of following shops:

1. Shop 13Main Processes: Turning, Milling, Gear hobbing, heat treatment, Carborizing, Lathe operation

2. Shop 15Main processes: Machining operations like planning, milling, boring, grinding, honing, CNC operation

3. Shop 17Main processes: Assembly of various components to form machine as per order of requirement done in this section.

4.2 PRODUCTS

Both CNC & conventional machine tools:

Vertical Turning & boring machine Heavy duty centre lathe Double Column Plano milling machine Double Column milling machine Radial drilling machine Horizontal boring & milling machine

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5 REFERENCE

1) Foundry Technology by Peter Beeley.2) Directional solidification of Steel casting by R. Wlodawer.3) www.wikipedia.org 4) www.hecltd.com

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