welding
welding is a process in which two or more parts are joined permanently at their touching surfaces by a suitable application of heat and/or pressure.
Welding types
solid state welding
in this process, joining of parts takes place by application of pressure alone or a combination of heat and pressure. no filler metal is used.
fusion welding
it is characterized by
arc welding
arc welding is a method of permanently joining two or more metal parts. it consists of combination of different welding processes wherein coalescence is produced by heating with an electric arc,(mostly without the application of pressure) and with or without the use of filler metals depending upon the base plate thickness
submerged arc welding (saw)
this is another type of arc welding process, in which coalescence is produced by heating the workpiece with an electric arc setup between the bare electrode and the work piece
shielded metal arc (smaw) or stick welding
this is arc welding process wherein coalescence is produced by heating the workpiece with an electric arc setup between a flux-coated electrode and the workpiece. the electrode is in a rod form coated with flux.
flux-cored arc welding (fcaw)
this process is similar to the shielded-arc stick welding process with the main difference being the flux is inside the welding rod
gas-metal arc welding (gmaw)
in this process an inert gas such as argon, helium, carbom dioxide or a mixture of them are used to prevent atmospheric contamination of the weld
gas-tungsten arc welding (gtaw)
this process is also known as tungste-inert gas (tig) welding. this is sililar to the gas-metal arc welding process. difference being the electrode is non consumable and does not provive fillar metal in this case.
plasma arc welding
this pr ocess is similar to TIG. a non-consumable electrode is used in this process. arc plasma is a temporary state of gas. the gas gets ionized after the passage of electric current and becomes a conductor of electricity. the plasma consists of free electrons, positive ions, and neutral particles.
resistance welding
resistance welding is a geoup of welding process in whisch coalescence is produced by the heat obtained from the resistance of the work to the flow of electric current in a circuit of which the work is a part and by the application of pressure. no filler metal is needed in this process
oxyfuel welding
this process is also known as oxy acetylene welding. heat is supplied by the combustion of acetylene in a stream of oxygen both gases are supplied to the torch through flexible hoses. heat from this torch is lower and far less concentrated than that from an electric arc
electron beam welding
electron beam welding is definedas a fusion welding process wherein coalescence is produced by the heat obtained from a concentrated beam of high velocity electron.when high velosity electrons strike the workpiece, kinetic energy is transformed into thermal energy causing localized heating and melding of the weld metal
laser beam welding
laser beam welding is defined as a fusion welding process and coalescence is achieved by utilizing the heat obtained from a concentrated coherent light beam and impinging upon the surface to be joined.this process uses the energy in an extremely concentrated beam of coherent,mono_chromatic light to melt the weld metal.
in this process, base metal is melted by means of heat
it is characterized by
diffucion welding
friction welding
in friction welding (solid state welding process) coalescence is produced by utilizing the heat obtained from the mechanically induced rotating motion between the rubbing surfaces.