manufacturing process of engine valve plant

8/3/2019 Manufacturing Process of Engine Valve Plant

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Manufacturing process of engine valve plant

One Month Industrial Training Report

In partial fulfillment for the award of the degree

of

BACHELOR OF TECHNOLOGY

IN

MECHANICAL ENGINEERING

At

Hi-Tech Institute of Engineering & Technology, Ghaziabad

Affiliated to

U.P Technical University, Lucknow

Submitted to:- Submitted by:-

Mechanical department Ashwani kumarHIET GZB Uni. Roll;no 0822040403


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This is to certify that Mr. Ashwani Kumar, student OfB.tech 3rd year mechanical

engineering from,Hi-Tech Institute Of Engineering And Technology Ghaziabad (U.P.) has successfully done his vocational training in the E.V Forge shop of Shri Ram

Pistons & Rings Ghaziabad. During his training period in Shri Ram Pistons & Rings

from 21th

June 2010 to 26th

July 2010, he has prepared a training report consisting of

the details of various shops. He possessed excellent conduct and has successfully

completed his training. I wish him great success in his future life.

Date: Mr Vikas Arora

Place: Ghaziabad

Shri Ram Pistons &

Rings Ltd Gzb


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ACKNOWLEDGMENT

I take great pleasure to acknowledge the people who have been involved in completion of

my project at different stages. It has been a privilege working with all those who have

been a part of this success story.

I give the credit of fruition of my project to my guide Mr.Vikash Arora, of shri ram

piston and ring limited. It was his support that I got valuable inputs towards my project.

I would also thank each member of Provisioning team at Shri Ram Piston & Ring

Limited, who always provided their valuable insights and helped me in completion of

allotted task.

Lastly, I would like to pay my sincere regards to each and everyone who directly or

indirectly helped me in my completion of the project and making it a success.


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CONTENTS

1. INTRODUCTION OF SHRI RAM PISTONS & RINGS LIMITED2. INTRODUCTION ABOUT ENGINE VALVE PLANT3. ABOUT FUNCTION OF ENGINE VALVE IN I.C ENGIN4. BASIS OF MATERIAL SLECTION5. ABOUT MATERIAL COMPOSTION6. CLASSIFICATION OF VALVE7. PROSSES OPERATION SEQUENCE8. BRIEF INTRODUCTION ABOUT EACH PROCESS RAW MATERIAL FRICTION WELDING UPSETTING FORGING HEAT TREATMENT SHOT BLASTING STRIGHTENING STEAM END CUT STELLITE GROOVING SEAT SETELLITING TIP DRILLING TIP SETELLITING END GRINDING ULTRASONIC INSPECTION POST OD TRAINING MACHINE SHOP


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INTRODUCTION OF SHRI RAM PISTONS & RINGS LIMITEDCompany Profile

Shriram Pistons & Rings Ltd ( SPRL ).Is a part of well Known Shriram Group of

Companies.SPRL is presently engaged in manufacturing of I.C Engine component

such as Pistons, Rings, Gudgeon pins,Engine Valves & Gears in collaboration with

world leaders like Kolbenschmidt of Germany&Honda Foundry of Japan for

Pistons ,Riken Corporation of Japan for Rings & Fuzi Oozx of Japan for Engine

valves. Companys product under USHA brand name are exported to over 60countries world wide including reputed OEMs.The company has QS-9000 &ISO/TS-16949 & EMS-14001, OHSAS-18001 accreditations under its belt & has

bagged the TPM(Total Productive Maintenance) Excellence award from JIPM,

Japan.


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Company Achievement's

1993 Commissioning of E.V plant. 1994ISO-9001 for Piston, Pin ,Ring Plant. 1995Commissioning of Automatic line for diesel pistons. 1996Exclusive supplier status with T.C.L. 1997 ISO-9001 for E.V plant 1998 Best vender Award (Maruti Suzuki). 1999QS-9000 :- Best supplier award (T.C.L)

. Export performance award.

ACMA quality award

2001ISO-14001 2003 TS-16949 & OHSAS-18001 Certification. 2004Comm.of automatic line for petrol piston& TPM Excellence award. 2007 preparation for TPM special award. 2008-09 best quality vendor award from tata moters 2009-10 best expoter award from FIEO


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Company Policy

T.P.M Policy

Zero failure, Zero Defect, Zero Accident through introduction of TPM, withinvolvement of all employees.

Quality Policy

Total customer satisfaction through Quality Management & continuous

improvement.

Environmental Policy

Continual improvement in environmental performance through prevention, monitoring

and control of pollution and improving environmental bench marks for sustainable

growth.


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INTRODUCTION ABOUT ENGINE VALVE PLANT

Engine valve plant related to manufacturing and machining of the engine valve.first all

the manufacturing process are completed by the prosses operation sequence then

manufactured product goes to machine shop for finishing of the product.

Engine valve plant is divided into two part

Engine valve forge shop Engine valve machine shop

Engine valve forge shop - Engine valve forging plant related to manufacturing of theproduct.In this plant all the process such as forging, upsetting and other manufacturingprocess are completed.

Engine valve machine shop - Engine valve machine shop related to related to thefinishing of product and production of engine valve is completed.

ABOUT FUNCTION OF ENGINE VALVE IN I.C ENGINE

FUNCTION - Inlet valve allow the fresh charge of air-fuel mixture to enter thecylinder bore.Exhaust valve permits the burnt gases to escape from the cylinder bore at

proper timing. Enginevalves are located in the cylinder head. The main function of the

engine valves is to let air in and out of the cylinders. That air is used to help ignite thefuel which will drive the pistons up and down.

There are two types of engine valves; intake and exhaust valves. The intake valves ofcourse let air in, and the exhaust valves let exhaust air out. The more air you can move air

in and out of the engine the more efficient, and therefor power the engine will have. This

is why the engine valve plays a pretty critical role in an engines performance.
http://hubpages.com/hub/Types-Of-Scavengings-Used-In-Internal-Combustion-Enginehttp://www.enginebasics.com/Advanced%20Engine%20Tuning/E85%20Basics.htmlhttp://www.enginebasics.com/Advanced%20Engine%20Tuning/E85%20Basics.htmlhttp://hubpages.com/hub/Types-Of-Scavengings-Used-In-Internal-Combustion-Engine


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Basis of Material Selection

To understand valve alloys, you need to know something about basic metallurgy. Thereare essentially two basic types of steel used to make valves. One is "martensitic" steel and

the other is "austenitic" steel. The difference is in the microstructure of the steel and how

the various ingredients in the alloy interact when the molten steel is cast and cooled. This

affects not only the hardness and strength of the steel, but also its corrosion resistance and

magnetic properties. As a rule, martensitic steels are magnetic while austenitic steels are

non-magnetic.

In martensitic steel, the steel is "quenched" (cooled) very quickly from a molten state to

freeze the grain structure in a particular configuration. Under a microscope, the grain

structure has a needle-like (acicular) appearance. This makes the steel very hard but also

brittle. Reheating and cooling the steel (a process called "tempering") allows some of the

martensite crystals to rearrange themselves into other grain structures which are not as

hard or brittle. By carefully controlling the heat treatment and quenching process, the

hardness and tensile strength of the steel can be fine tuned to achieve the desired

properties.

Steel alloys with a martensitic grain structure typically have a high hardness at room

temperature (35 to 55 Rockwell C) after tempering, which improves strength and wear

resistance. These characteristics make this type of steel a good choice for applications

such as engine valves.

But as the temperature goes up, martensitic steel loses hardness and strength. Above

1000 F or so, low carbon alloy martensitic steel loses too much hardness and strength to

hold up very well. For this reason, low carbon alloy martensitic steel is only used for

intake valves, not exhaust valves. Intake valves are cooled by the incoming air/fuel

mixture and typically run around 800 to 1000 F, while exhaust valves are constantlyblasted by hot exhaust gases and usually operate at 1200 to 1450 F or higher.

To increase high temperature strength and corrosion resistance, various elements may be

added to the steel. On some passenger car and light truck engines, the original equipment

intake valves are 1541 carbon steel with manganese added to improve corrosion


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resistance. For higher heat applications, a 8440 alloy may be used that contains

chromium to add high temperature strength. For many late model engines (and

performance engines), the intake valves are made of an alloy called "Silchrome 1" (Sil 1)

that contains 8.5 percent chromium.

Exhaust valves may be made from a martensitic steel with chrome and silicon alloys, or a

two-piece valve with a stainless steel head and martensitic steel stem. On applications

that have higher heat requirements, a stainless martensitic alloy may be used. Stainless

steel alloys, as a rule, contain 10 percent or more chromium.

The most popular materials for exhaust valves, however, are austenitic stainless steel

alloys such as 21-2N and 21-4N. Austenite forms when steel is heated above a certain

temperature which varies depending on the alloy. For many steels, the austenitizing

temperature ranges from 1600 to 1675 F, which is about the temperature where hot

steel goes from red to nearly white). The carbon in the steel essentially dissolves andcoexists with the iron in a special state where the crystals have a face-centered cubic

structure. By adding other trace metals to the alloy such as nitrogen, nickel and

manganese, the austenite can be maintained as the metal cools to create a steel that has

high strength properties at elevated temperatures. Nitrogen also combines with carbon to

form "carbonitrides" that add strength and hardness. Chromium is added to increase

corrosion resistance. The end product is an alloy that may not be as hard at room

temperature as a martensitic steel, but is much stronger at the high temperatures at which

exhaust valves commonly operate.

Though austenitic stainless steel can handle high temperatures very well, the steel is

softer than martensitic steel at lower temperatures and cannot be hardened by heattreating. To improve wear, a hardened wafer tip may be welded to the tip of the valve

stem. Or, on some applications an austenitic stainless valve head may be welded to a

martensitic stem to create a two-piece valve that has a long wearing stem and heat

resistant head. The only disadvantage with a two-piece valve is that it doesn't cool as well

as a one-piece valve. The junction where the two different steels are welded together

forms a barrier that slows heat transfer up the stem.

21-2N alloy has been around since the 1950s and is an austenitic stainless steel with 21percent chromium and 2 percent nickel. It holds up well in stock exhaust valve

applications and costs less than 21-4N because it contains less nickel. 21-4N is also an

austenitic stainless steel with the same chromium content but contains almost twice as

much nickel (3.75 percent), making it a more expensive alloy. 21-4N is usually

considered to be the premium material for performance exhaust valves. 21-4N steel also


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meets the "EV8" Society of Automotive Engineers (SAE) specification for exhaust

valves.

SAE classifies valve alloys with a code system: "NV" is the prefix code for a low-alloy

intake valve, "HNV" is a high alloy intake valve material, "EV" is an austenitic exhaust

valve alloy, and "HEV" is a high-strengthexhaust valve alloy.Unfortunately, you can't always tell what kind of alloy a valve is made from because

different valve suppliers use different alloys as well astheir their own proprietary names

for their valve materials. Thus one manufacturer may call their intake valve material a

"422 stainless alloy" while another refers to it as an "NK-842 stainless intake material."

Without a thorough metallurgical analysis, you can't really compare one manufacturer's

valve material to another's. But do you really need such a comparison? As long as the

alloy does what it is supposed to do, it doesn't matter what they call it.

The bottom line here is that intake valves and exhaust valves both require different types

of alloys. The same alloy can be used for both intake and exhaust valves (say 21-2N or21-4N, for example), but the best results are usually obtained when different alloys are

selected for the intake and exhaust valves. Why? Because an exhaust alloy that has good

high temperature strength and corrosion resistance really isn't needed on the intake side,

and it may not have the hardness and wear resistance of an intake alloy at lower

temperatures. Even so, some companies sell the same alloy for both intake and exhaust

valves while others offer different alloys for intake and exhaust valves.

Intake valves run cooler and are washed with fuel vapors which tend to rinse away

lubrication on the valve stem. So for intake valves, wear resistance may be more

important than high temperature strength or corrosion resistance if the engine will be

involved in any kind of endurance racing. Exhaust valves, on the other hand, run muchhotter than intake valves and must withstand the corrosive effects of hot exhaust gases

and the weakening effects of high temperatures. Consequently, a premium valve material

is an absolute must on the exhaust side - especially in turbocharged and supercharged

engines and those that inject nitrous oxide to boost power.

As combustion temperatures go up, valve alloys that work fine in a stock engine may not

have the strength, wear or corrosion resistance to hold up in a performance application. If

you want thevalves to last, especially in a highly modified racing engine, upgrading to

better valve alloys will be a must.

The best advice is to follow the valve alloy recommendations of your valve supplier, and

to rely on their expertise when it comes to picking the best valve material for a

performance application. If a stock valve alloy is holding up well enough in a

performance application, there's no need to upgrade. But if an engine is experiencing

valve burning or premature valve failure, then an upgrade to a better material may be

needed to solve the problem.


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Selection of material on the basis of properties

CRITERIA OF INLET VALVE High wear resistance Corrosion resistance High strength Availability of material supplied Overall cost (material and manufacturing costs )

CRITERIA OF EXHAUST VALVE Resistance to high-temperature corrosion [ 700C ] Hot strength (endurance strength at high temperature )[ ~500MPa ] Hot hardness [ strength at ~700C ] Resistance to oxidation Resistance to seizing and galling Availability of material supplied Overall cost (material and manufacturing costs)ABOUT MATERIAL COMPOSTION

Steel Nickel

Melting Point( > 400C )

Tensile Strength x(~500MPa)

Cost of material moderate High (Moderate)`

relative to relative to

Nickel steel

From the table shown above, the material that fulfill our criteria is onlySTEEL.

Therefore we eliminate nickel and so only left the steel group.


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From thestrength-temperatureashby chart,the suitable steel hadbeen chosen is

STAINLESS STEEL.

Stainless Steels are iron-base alloys containing Chromium. Stainless steels usuallycontain less than 30% Cr and more than 50% Fe. They attain their stainless

characteristics because of the formation of an invisible and adherent chromium-rich oxide

surface film. This oxide establishes on the surface and heals itself in the presence of

oxygen.

Stainless steels are commonly divided into five groups: Martensitic stainless steels Ferritic stainless steels Austenitic stainless steels Duplex (ferritic-austenitic) stainless steels

Precipitation-hardening stainless steels.


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Finally, the specific type of material that we choose is

Austenitic stainless steels Martensitic stainless steels


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CLASSIFICATION OF VALVES

ENGINE VALVES

INLET VALVE EXHUST VALVE

INLET VALVE - Inlet Valve is that valve through which fuel or a mixture whosepressure in increased by reducing its volume in intaked into the cylinder.

EXHUST VALVE -Exhaust valve is precision engine components used toopen to permit the burned gases to exhaust from cylinders. Therefore exhaust valve areexposed to serve thermal loads and chemical corrosion.Exhaust valve are opens andcloses as many as 2000 times per mile


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PROSSES OPERATION SEQUENCE

RAW MATERIAL

FRICTION WELDING &DFLASH

UPSEETING

FORGING

HEAT TREATMENT

SHOT BLASTING

STRIGHTENING

STEAM END CUT

STELLITE GROOVING

SEAT SETELLITING


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TIP DRILLING

TIP SETELLITING

END GRINDING

ULTRASONIC INSPECTION

POST OD TRAINING

MACHINE SHOP


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BRIEF INTRODUCTION ABOUT EACH PROCESS

RAW MATERIAL-A Raw material or feedstock is the basic material from whicha product is manufactured or made, frequently used with an extended meaning. First, the

raw material ( Stainless Steel rod ) is undergoing hot directextrusion to get the required

diameter.

FRICTION WELDING - Friction welding is a process of joining head diameter ofthe engine valve with the straight rod use fully automatic machine. It is needed only for

the bimetallic valve. Friction welding technology is a completely mechanical solid-phase

process in which heat generated by friction is used to create high-integrity joint between

similar or dissimilar metals, and even thermoplastics.

Advantages :1. High production volume

2. Low cost per pound

3. Many types of raw material

Disadvantages :1. Limited complexity of parts2.Uniform cross-section shape only

UPSETTING -After the raw material is undergoing extrusion, the next step isupsetting

process. This process purpose is to give initial shape that will be forwarded to next step

that is forging process.

Steps :

1.The steel is heated by electrical resistance between two contacts.

2.As the steel reaches its plastic temperature more material if forced through the

contacts by a hydraulic ram until enough volume is "upset" to make the pre-form.

3.Then, the pre-form is then passed immediately to the forge.


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FORGING- Forging is the process by which metal is heated and is shaped by plasticdeformation by suitably applying compressive force. Usually the compressive force is in

the form of hammer blows using a power hammer or a press. After upsetting process the

upsetted part will go through forging process immediately. Forging is the term for

shaping metal by using localized compressive forces. The forging process of producing

exhaust valve is Hot Forging on Friction Screw and High Speed Precision ForgingPresses, where the press capacity is 5kgs.

Forging

Forging refines the grain structure and improves physical properties of the metal. With

proper design, the grain flow can be oriented in the direction of principal stresses

encountered in actual use. Grain flow is the direction of the pattern that the crystals take

during plastic deformation. Physical properties (such as strength, ductility and toughness)

are much better in aforging than in the base metal, which has, crystals randomly

oriented.All of the following forging processes can be performed at varioustemperatures, however they are generally classified by whether the metal temperature is

above or below the recrystallization temperature. If the temperature is above the

material's recrystallization temperature it is deemed hot forging; if the temperature is

below the material's recrystallization temperature but above310ths of the recrystallization

temperature (on an absolute scale) it is deemed warm forging; if below310ths of the

recrystallization temperature (usually room temperature) then it is deemed cold forging.


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The main advantage of hot forging is that as the metal is deformed work hardening

effects are negated by the recrystallization process. Cold forging typically results in work

hardening of the piece.The most common type of forging equipment is the hammer and

anvil. Principles behind the hammer and anvil are still used today in drop-hammer

equipment. The principle behind the machine is very simpleraise the hammer and then

drop it or propel it into the workpiece, which rests on the anvil. The main variations

between drop-hammers are in the way the hammer is powered; the most common beingair and steam hammers. Drop-hammers usually operate in a vertical position. The main

reason for this is excess energy (energy that isn't used to deform the workpiece) that isn't

released as heat or sound needs to be transmitted to the foundation. Moreover, a large

machine base is needed to absorb the impacts.

To overcome some of the shortcomings of the drop-hammer, the counterblow machine or

impactor is used. In a counterblow machine both the hammer and anvil move and the

workpiece is held between them. Here excess energy becomes recoil. This allows the

machine to work horizontally and consist of a smaller base. Other advantages include lessnoise, heat and vibration. It also produces a distinctly different flow pattern. Both of these

machines can be used for open die or closed die forging.

A forging press, often just called a press, is used for press forging. There are two main

types: mechanical and hydraulic presses. Mechanical presses function by using cams,

cranks and/or toggles to produce a preset (a predetermined force at a certain location in

the stroke) and reproducible stroke. Due to the nature of this type of system, different

forces are available at different stroke positions. Mechanical presses are faster than their

hydraulic counterparts (up to 50 strokes per minute). Their capacities range from 3 to 160

MN (300 to 18,000 short tons-force). Hydraulic presses use fluid pressure and a piston togenerate force. The advantages of a hydraulic press over a mechanical press are its

flexibility and greater capacity. The disadvantages include a slower, larger, and costliermachine to operate.
http://en.wikipedia.org/wiki/Work_hardeninghttp://en.wikipedia.org/wiki/Work_hardening


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Forging prosses

Advantages :1..Flexibility of design process

2.Versatility of the forging itself.

Disadvantages :1.The skill involved is not easily acquired

2.Tooling needed represents a considerable amount of time and money invested.

HEAT TREAMENT- The next step after the exhaust valve had been forged is heat treatment.Heat treatment of these grades consists of solution treatment so as to get a single phase structure.heat

treatment prosses of engine valves are completed into three steps.


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HEAT TREAMENT

QUENCHING WASHING TEMPERING

QUENCHING - Quenching is the rapid cooling of a workpiece to obtain certainmaterial properties. It prevents low-temperature processes, such as phase transformations,

from occurring by only providing a narrow window of time in which the reaction is both

thermodynamically favorable and kinetically accessible. For instance, it can reduce

crystallinity and thereby increase toughness of Stainless Steel rod.

Quenching metals is a progression; the first step is soaking the metal, i.e. heating it to the

required temperature. Soaking can be done by air (air furnace), or a bath. The soaking

time in air furnaces should be 1 to 2 minutes for each millimeter of cross-section. For abath the time can range a little higher. The recommended time allotment in salt or lead

baths is 0 to 6 minutes. Uneven heating or overheating should be avoided at all cost. Most

materials are heated from anywhere to 815 to 900 C (1,500 to 1,650 F).

WASHINGAfter quenching washing is the next step.In washing quenched productwashed by water.then it goes for tempering.

TEMPERING- Untempered martensitic steel, while very hard, is too brittle to beuseful for most applications. A method for alleviating this problem is called tempering

Heating a quench hardened or normalized ferrous alloy to a temperature below the

transformation range to produce desired changes in properties. The object of tempering or

drawing is to reduce the brittleness in hardened steel and to remove the internal strains
http://en.wikipedia.org/wiki/Coolinghttp://en.wikipedia.org/wiki/Material_propertieshttp://en.wikipedia.org/wiki/Phase_%28matter%29http://en.wikipedia.org/wiki/Crystallinityhttp://en.wikipedia.org/wiki/Crystallinityhttp://en.wikipedia.org/wiki/Phase_%28matter%29http://en.wikipedia.org/wiki/Material_propertieshttp://en.wikipedia.org/wiki/Cooling


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Abrasive delivery methodThere are two ways of accelerating the steel shot:

a) By compressed airThis system is suitable for lower production applications where maximum flexibility is

needed. These systems are very flexible in that

the shot can be delivered horizontally through a rubber hose and nozzle

assembly. This enables uses in finishing operations of steel frames andweldments thereby

replacing hand tools. Because of this, an air blasting machine for a production line is

expensive compared to the centrifugal wheel blasting machine. For example to deliver

shot at a rate of 1100 kg per minute a 1650 Hp compressor and 33 workers are needed

using

10 mm diameter nozzles delivering 6.5 kg/cm2. On the other hand the same task using

centrifugal wheel turbines only requires a total of 100 Hp distributed to between one or a

multitude of turbines housed in the same machine. Only one or two operators are needed

for such a shotblasting machine.

Shot blasting by compressed air

b) By centrifugal turbineCentrifugal wheel blasting is the more common blast cleaning technique as well as themost economical and environmentally friendly method. The turbine delivers abrasive

shot by centrifugal force in a specific andcontrolled direction, speed and quantity.Function of the turbine is similar to that of a fan or centrifugal pump. Shot blasting

machines mayuse one or a multitude of turbines positioned in such a way that theabrasive blast pattern covers the entire surface of the material to be shot cleaned. The

shape and size of the parts determine thnumber of turbines. used in a machine. Power of


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the turbine motor is based on degree of cleaning needed and throughout speed of the

material.

Shot blasting by centrifugal turbine

.

.

STRIGHTENING - During the heat treatment process temperature of the valvebecome very high. At this high temperature there are some bending occure in engine

valve. So in this process valve is passes through between two die at high pressure.by

which bending from valve is reduce at considerable level.

STEAM END CUT - Afterstrighting prosses the length of stem of the enginevalve is increases due to increases in the straightness of the stem.so the undesirable

length of the stem is cut by the cutter.the length of the stem is taken as fixed standard

which are followed by the company.

STELLITE GROOVING- This prosses is used to increase the strength of thestet of the engine valve.In this prosses a groove is made at the valve seat in which filler

material is filled.

SEAT SETELLITING - The follow up process after the heat treatment is satellitewelding process.Stellite is a special alloys that welded onto the seat.Purpose is to

improve the corrosion and high temperature wear resistance, mainly in valves; a cord of

special material is placed onto the valve seat.


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Advantages :

1.High residual stresses are relieved

2. Hardness improved3. Overlaid with corrosion and wear resistant material (stellite) for long service life.

TIP DRILLINGSome time there in need to increase the strength of the tip of theengine valve.so tip drilling is the first step to increase the strength of the engine valve.soby drilling space in the tip of engine valve is made to fill the filler matel.

TIP SETELLITING - The next process is tip hardening process. The machine usedis fully

automatic machine, which is Valve Stem-End Induction Hardening machine that can

provide perfect quality of hardening. The purpose of this process is to increase the wear

resistant of the tip since this part is continuously pounded by camshaft during theoperation of exhaust valve.

Advantages :1.Increasing the cyclic crack resistance of structural parts.


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END GRINDINGAfter tip setelliting there is some unwanted material remainingat the tip of the engine valve.so to remove the unwanted material grinding of the tip of the

engine valve is necessary.so in this prosses grinding of the tip is done.

ULTRASONIC INSPECTION During the manufacturing process there issome chance of forming of blow hole or crack inside the engine valve.so it is necessary tofound these blow hole or crack inside the engine valve.so ultrasonic inspection is used for

this purpose. In ultrasonic testing (UT), very short ultrasonic pulse-waves with center

frequencies ranging from 0.1-15 MHz and occasionally up to 50 MHz are launched into

materials to detect internal flaws or to characterize materials. The technique is also

commonly used to determine the thickness of the test object, for example, to monitor

pipework corrosion.Ultrasonic testing is often performed on steel and other metals and

alloys, though it can also be used on concrete, wood and composites, albeit with less

resolution. It is a form of non-destructive testing used in many industries including

aerospace, automotive and other transportation sectors.
http://en.wikipedia.org/wiki/Ultrasoundhttp://en.wikipedia.org/wiki/Metalshttp://en.wikipedia.org/wiki/Non-destructive_testinghttp://en.wikipedia.org/wiki/Aerospacehttp://en.wikipedia.org/wiki/Automotivehttp://en.wikipedia.org/wiki/Transportationhttp://en.wikipedia.org/wiki/Transportationhttp://en.wikipedia.org/wiki/Automotivehttp://en.wikipedia.org/wiki/Aerospacehttp://en.wikipedia.org/wiki/Non-destructive_testinghttp://en.wikipedia.org/wiki/Metalshttp://en.wikipedia.org/wiki/Ultrasound


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Ultrasonic inspection

Advantages

1. High penetrating power, which allows the detection of flaws deep in the part.2. High sensitivity, permitting the detection of extremely small flaws.3. Only one surface need be accessible.4. Greater accuracy than other nondestructive methods in determining the depth of

internal flaws and the thickness of parts with parallel surfaces.

5. Some capability of estimating the size, orientation, shape and nature of defects.6. Nonhazardous to operations or to nearby personnel and has no effect on equipment

and materials in the vicinity.

7. Capable of portable or highly automated operation.


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Disadvantages

1. Manual operation requires careful attention by experienced technicians2. Extensive technical knowledge is required for the development of inspectionprocedures.3. Parts that are rough, irregular in shape, very small or thin, or not homogeneous are

difficult to inspect.

4. Surface must be prepared by cleaning and removing loose scale, paint, etc.,although paint that is properly bonded to a surface need not be removed.

5. Couplants are needed to provide effective transfer of ultrasonic wave energybetween transducers and parts being inspected unless a non-contact technique is

used. Non-contact techniques include Laser and Electro Magnetic Acoustic

Transducers (EMAT).

6. Inspected items must be water resistant, when using water based couplants that donot contain rust inhibitors.

MACHINE SHOPAfter all process in forge shop forge blank goes for machiningin machine shop for finishing. The final step is surface finishing. The surface finishing

chosen for exhaust valve is by chard chrome plating at the contact area at the valve stem.

The chrome thickness is from 3m to 7m. This step is to enhance the lifetime of valves.It increase Characterize surface roughness and quality.Conventional machining is a

collection of material-working processes in which power-driven machine tools, such assaws, lathes, milling machines, and drill presses, are used with a sharp cutting tool to

mechanically cut the material to achieve the desired geometry. Machining is a part of the

manufacture of almost all metal products, and it is common for other materials, such as

wood and plastic, to be machined. A person who specializes in machining is called a

machinist. A room, building, or company where machining is done is called a machine

shop. Much of modern day machining is controlled by computers using computernumerical control (CNC) machining. Machining can be a business, a hobby, or both.
http://en.wikipedia.org/wiki/EMAThttp://en.wikipedia.org/wiki/EMAThttp://en.wikipedia.org/wiki/Machine_toolshttp://en.wikipedia.org/wiki/Lathe_%28tool%29http://en.wikipedia.org/wiki/Milling_machinehttp://en.wikipedia.org/wiki/Drill_presshttp://en.wikipedia.org/wiki/Machinisthttp://en.wikipedia.org/wiki/Machinisthttp://en.wikipedia.org/wiki/Numerical_controlhttp://en.wikipedia.org/wiki/Numerical_controlhttp://en.wikipedia.org/wiki/Numerical_controlhttp://en.wikipedia.org/wiki/Numerical_controlhttp://en.wikipedia.org/wiki/Numerical_controlhttp://en.wikipedia.org/wiki/Machinisthttp://en.wikipedia.org/wiki/Drill_presshttp://en.wikipedia.org/wiki/Milling_machinehttp://en.wikipedia.org/wiki/Lathe_%28tool%29http://en.wikipedia.org/wiki/Machine_toolshttp://en.wikipedia.org/wiki/EMAT

manufacturing process of engine valve plant

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