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
classified
solid-state welding: in this process, joining of part takes place by aplication of pressure alone or a combination of heat and pressure. No filler metal is used.commonly uesd solid-state welding processes are:
diffusion welding
parts are pressed together at an elevated temperature below the melting point for a period of time
friction welding
in friction welding (solid state weldign process) coalescence is produced by utilizing the heat obtained from the mechanically induced rotating motion between the rubbing surfaces
ultrasonic welding
this process utilizes transverse oscillation of one part against the other to develop sufficient heat for fusion to occur
fusion welding: In this process, base metal is melted by means of heat. commonly used fusion welding. processes:
Arc welding
is a method of permnently joining two or more metal parts
this is an arc welding process wherein coalescence is produced by heating the workpiece with an electric arc setup between a flux-coated electrode and the workpiece
shielded-metal are (smaw) or stick welding
submerged arc welding (smaw)
this is another type of arcwelding process, in whitch coalescence is produced by heating the workpiece with an electric arc setup between the barevelectrode and the work piece
flux -cored arc welding
this is process is similar to the shielded-arc stick welding process with the main difference being the flux is inside welding rod
gas-metal arc welding
in this process and inert gas such as argon, helium, carbon dioxide or a mixture of them are used to prevent atmospheric contamination of the weld
Gas-tungsten arc welding
this process is also known as tungsten-inertgas (tig) welding. this is similar to the gas metal arc welding process.
plasma arc welding
this process is similar to tig. A non-consumable electrode is used in this process. Arc plasma i a temporary state of gas
resistance welding
is a group of welding process in which coalescence is produced by the heat obtained from the resistance of the work to the flow of electric current in a circuit of whitch the work is a part and by the application of pressure.
oxyfurl welding
this process is also known as oxy-acetylene welding. heat is supplied by the combustion of acetylene in a stream of oxygen.
electron beam welding
electron beam welding is defined as a fusion welding process wherein coalescence is produced by the heat obtained from a concentrated beam of high velocity electron.
laserbeam 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