Sunday, August 26, 2012

Advantage & Disadvantage of Welding


*Advantage of  Welding
1) It produces permanent joint.
2) Overall cost of weldng equipments is general low
3) Many portable welding equipment are available.
4) large number of metl can be welded.
5) A good weld is as strong as base metal.
6) Welding can be mployed from limited portion to ny leght.

*Disadvantage of Welding
1) Welding creates residual stresses and distortion in work piece.
2) Edge preperation is generaly required before welding.
3) Good traring required to make a weldr skilled.
4) Welding produces structural,physical and chemical changes.
5) Jigs and fixtures are needed to hold parts in position.
6) Welding gives off harmful radiations,fumes and spatters.

Welding


Welding can be defined as the process of joining similar metal by the application of heat ,with or without the application of pressure and filler metal.in such way that the welded component is continuity o homogeneous material having the sane composition and characteristic as the two part to be joined together.the cast of welding is very less as compared to the other metal joining process like riveting,nut-bolts and form of a spong joint.

Types Of Welding
1)Fusion Welding
In Fusion Welding ,initially the temperature of parent metal is raised up to the melting point then filler metal is used as suppliment for molten pol.A Homogeneous mixture is formed at the joint then it is allowed to solidify to form a weld.

2)Pressure Welding
The ends to be joined as brought to plastic stat and then apply external pressure to joint them.

Forge able Material & Forging Tools

* Forge able Materials
Some Forge able Material in order of increasing forging difficulty are listed below.

Aluminium alloy (good)
Magnesium alloy (good)
Copper alloy (good)
Carbon/low alloy steel ( some more difficult )
Marten stainless steel ( some more difficult )
Ma-raging steels ( some more difficult )
Austen stainless steel ( some more difficult )
Nickel alloy ( some more difficult )
Titanium alloy ( some more difficult )
Iron based super alloy ( Difficult )
Cobalt base alloy ( Difficult )
Tantalum alloy ( Difficult )
Tungsten alloy ( Very difficult )
Beryllium alloy ( Very difficult )

* Hand Forging Tools
Anvil
S wage block
Hammers
Tongs
Chisels
Punches & Drift
Fullers
S wages
Flatters
Sett Hammer
Brick Iron

Forging


Forging : Forging is the process of heating and plastically deforming metals or aloys to a specific shape by a compressive forece exerted by an upsetting maching of same kind.

Forge ability : Forge ability of  material is the capacity of a material to undergo deformation under alloy which can brought to plastic stage through heating can be forged.

Foregeability of materials mainly depend upon on:

* Metallurgical factors
1)Compression and purity of material
2)Number of phase present
3)Grain size

* Mechanical factors
1)Strain rate
2)Strain distribution

In comparison to machining and casting,forging has following advantage and disadvantage.
Advantage of Forging:
1)Strenght and toughness is high.
2)The material required to produce a component is less.
3)Internal porosity like segegation,cracks and porosity are eliminated.
4)Has ability to withstand higher loads.
5)component can be produced to close tolerance.

Disadvantage of 

Lathe Machine

Lathe Machine is a particular type of machine tool in which the work is held and rotated against a suitable cutting tool for the purpose of producing surfaces of revolution in any material.the different operations carried out in the lathe machine are

Turning : It is operation of metal removal in which job is rotated against a  tool.

Knurling : The process of making diamond shape impressions on the surface of a component to produce a rough surface to facilitate easy grip.

Facing : The process of the material removal from the surface at right angle to the axis of rotation of the job.

Drilling : The process of producing hole in an object.

Boring : The process of enlarging a hole,which has already been drilled or casted or punched.

Reaming : The process of removing very small amount of materials,to make the drilled holes in very accurate                        size.

Threading : The removal of materials to produce helix on external or internal circular surfaces for fastening purposes.

Tapping : The process of making internal thread with help of a tool called tap.

Information About This Blog

this is my first post for this blog.i created this blog so i can share the knowledge which i learn from the college.i am the student of diploma in automobile engineering so i will share the knowledge about the workshop.you can learn the information about the machines,safety measure,precaution and many more on this blog.i hope you guys will like it and will get some basic information about workshop.i am in second semesiter now so i learn something about machines but not a lot anyway.i will try my best to provide the information which you want.i will help you guys to how to run the machines and how to handle the equipment in the workshop.i will share everything i learn in my college.if you want something to know about something else which belongs to my subject then comment on the post or contact me.