introduction to weld

8/8/2019 Introduction to Weld

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INTRODUCTION

TO

WELDING

P.SURESH KUMAR

ME I YEAR


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INTRODUCTION

Welding is a process of joining similar metals by

application of heat with or without application of

pressure and addition of filler material. Theresult is a continuity of homogeneous material of

the composition and characteristics of two parts

which are being joined together.


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Weldability

The term weldabillity has been defined as

the capacity of being welded into

inseparable joints having specifiedproperties such as definite weld strength,

proper structure.


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Types of welding

Modern methods of welding may be

classified under two broad headings

1. Plastic welding (pressure welding)

2. Fusion welding (non pressure welding)


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Plastic welding

The pieces of metal to be joined are

heated to a plastic state and then forced

together by external pressure.

Ex: Forge welding, resistance welding


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Plastic welding


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Fusion welding

The material at the joint heated to a molten state

and allowed to solidify.

Ex: gas welding , thermit welding


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Fusion welding


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Weldingprocess

Gas weldinga) Oxyacetylene

Arc welding

a) Gas metal arc (MIG)b) Gas tungsten arc (TIG)

Resistance welding

Thermit welding

Solidstate welding

Newerwelding


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Weldingprocess

Gas welding

1. Oxyacetylene

Oxyacetylene gas welding isaccomplished by melting the edges or

surface to be joined by gas flame and

allowing the molten metal to flow

together ,thus forming a solid continuous

joint upon cooling.


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Weldingprocess

Gas welding

1. Oxyacetylene


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Weldingprocess

Arc welding

1.Gasmetalarc (MIG)

gas metal arc welding is a gas shielded,metal- arc welding process which uses the

high heat of an electric arc between a

continuously fed , consumable electrode

wire and the material to be welded.


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Weldingprocess

Arc welding

Gasmetalarc (MIG)


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Weldingprocess

Arc welding

Gastungsten Arc welding (TIG)

This arc welding process uses the intenseheat of an electric arc between a non

consumable tungsten electrode and the

material to be welded.


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Weldingprocess

Arc welding

Gastungsten Arc welding (TIG)


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Weldingprocess

Resistance welding

In resistance welding the metal parts to be

joined are heated to a plastic state over alimited area by their resistance to the flow

of an electric current and mechanical

pressure is used to complete the weld.


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Weldingprocess

Resistance welding


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Weldingprocess

Thermit welding

thermit welding is primarily a fusion

welding process in which the weld iseffected by pouring superheated liquid

thermit steel around the parts to welded.


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Weldingprocess

Thermit welding


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Weldingprocess

Solidstate welding

inter atomic bonds may be established by

bringing atoms of two surfaces in closeenough proximity to assure welded

surfaces under pressure.


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Weldingprocess

Solidstate welding


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Weldingprocess

Newerwelding

Electron Beam Welding

electron beam welding utilizes theenergy from a fast moving of electrons

focused on the work piece.


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Weldingprocess

Newerwelding

Electron Beam Welding


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Weldingprocess

Laserbeam welding

laser are devices which are capable of

generating a very intense beam of opticalradiation.


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Weldingprocess

Laserbeam welding

introduction to weld

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