welding essentialsWelding-Applications-Sectors
Welding Technology is now essential for any industrial sector. Welded products are very common even for electrical and domestic appliances. Even for precision instruments and jewelry various joining methods are employed. Hence welding is inevitable for very fine to very heavy fabrication requirements.
http://www.arcmachines.com
1. Industrial sectors -best applications
Welding applications range from very small to heavy fabrication in
various industrial sectors in the world.
Power sector (hydel, thermal, nuclear, solar, wind power) extensively employs welding for many critical products manufacture.http://www.researchgate.net
Transportation sector (surface, sea, air) makes use of several welding processes. Automobiles (two wheelers, cars, buses) use many of the resistance welding processes.http://www.schlattergroup.com Ship building uses manual metal arc welding, submerged arc welding, electro gas welding, gas metal arc welding processes.http://www.lincolnelectric.com
Aerospace applications require advanced welding processes like electron beam, laser, friction welding http://www.kuka.comand diffusion bonding processes.http://www.ebindustries.com
Transition joints are required for handling difficult to weld dissimilar metal combinations. Friction welding , ultrasonic welding , explosive welding and induction pressure welding are some of the processes useful for such applications.
2.Welding of tubes and pipes :
Tubes are generally below 108 mm dia and pipes have above this diameter. Welding is carried out in workshops or at sites extensively.Shielded metal arc,Gas tungsten arc,Gas metal arc, plasma arc, flash butt welding, induction pressure welding,Magnetically impelled arc butt welding can be employed.
Automatic welding equipment have good controls for setting and monitoring parameters.Quality is established by NDT methods.
Manual welding requires qualified and certified welders as the applications are very critical like steam pipes, gas pipes, oil pipes.
Selection of consumables for various pipe materials is very important.API,ASME and other relevant standards need to be referred.
3.Dissimilar welds and applications:
There are many challenging industrial applications where typical-dissimilar metal combinations find use.
Electrical industries require joints between Al-steel,stainless steel, copper to get specific advantages : cost savings, required properties.
Power sector uses transition joints between low carbon steels, low alloy steels, stainless steel for high temperature and high pressure service.
Aero space applications require joints between titanium alloys ,aluminium alloys, stainless steels.
Automotive applications include joints between low alloy steels to inconel alloys.
Tool manufacture uses joints between medium carbon steels to high speed steels.
Welding process selection plays an important role considering the challenges involved regarding weldability.Some important processes are 1.Friction welding2.Explosive welding 3.Induction pressure welding 4 Diffusion bonding 5 Ultrasonic welding 6.Flash butt welding 7.Strip cladding 8. Plasma spraying 9.Plasma surfacing 10. Detonation spraying. 11. Electron beam welding 12.Laser beam welding.
Welding reviews
4.Friction welding for challenging applications
After the commercial use in 1956 there has been exponential growth for friction based processes all over the world. Automobile sector uses for mass production of critical components, like
valves,axles,rocker arm,etc.
Electrical industries use for joining dissimilar metal components
like Al- Cu joints( earthing connectors),Tungsten copper to copper joints,electrode tips etc.
Tools industry uses for dissimilar joints between Medium carbon steel to tool steel for drills manufacture.
Typical applications involve multiple metal welding involving dissimilar metals.
5.Welding in power plant fabrication
Thermal,Hydel,nuclear power plant equipment manufacture involves extensive welding.Many high temperature materials like Low alloy steels, stainless steels, Inconel are used for high temperature ,high pressure applications.Low carbon steels are used for many requirements like boilers,headers,structures,furnace walls, boilerauxiliaries.tubes,pipes etc.
The processes widely used are 1.SMAW,GTAW,GMAW,SAW
2.ESW,Orbital TIG,Tube to tube sheet special purpose GTAW welders,Strip cladding,
3.Automatic welding processes like tube butt welders,Induction pressure welder,Flash butt welders,Projection welders,spot ,seam welders,semi automatic carbon dioxide GMAW welders .
Others: EBW,LASER,Narrow gap SAW,Narrow gap TIG
6.Welding in Transportation sector
Transportation sector includes automobiles,Railways,Ships,defence vehicles,Aerospace applications.
Automobiles use many automatic welding equipment for mass production with GTAW,GMAW,SAW,RSW,FBW,FW,RPW,Seam welding,HFBSW.SMAW also is used now a days but to a lesser extent.Robotic welders using spot welding,GMAW are used for improved productivity.
7.Railways
Railway coaches,Rails,wagons etc require processes such as GMAW,RSW,FBW,GTAW,foil butt seam welding,apart from SMAW.
8.Aero space applications
Since aluminium alloys ,managing steel,and titanium alloys are used for critical applications ,processes like EBW,LASER,FW,GTAW,Diffusion bonding,GMAW,Plasma welding,spraying,EXW find highly useful to meet high quality requirements.Special purpose welding machines are required to weld critical components as 100% quality to be assured.These machines are very costly.
6.Ships,submarines
Extensive welding is done in the manufacture of large size ships.Submarines involve special alloys and require high quality joints.Some of the processes recommended are SMAW,GMAW,GTAW,FCAW,SAW.Special purpose machines with good control over parameters are required to weld high strength alloys.
7.Automation and Robotics
Low cost automation,full automation are now a days employed for
improving productivity in many industrial sectors.
In the last few years Robotic automation is employed using Robotic GMAW,Robotic spot welding,Robotic friction stir welding.
Robotic weld systems with sensors are employed in ship building,automotive industries for full automation.
8.Friction stir welding applications in various industries
After the invention in 1991, there has been exponential growth for this process.Many industries started using this process to advantage.Aluminium alloys
employed in various industries are successfully welded for sheet to sheet butt joints. As the process also facilitates lap joints,and T joints many industries are showing keen interest to apply.Dissimilar metals also can be joined as there is no melting and solidification in this process.
Ship building applications include:
Panels for decks, sides, bulkheads and floors Aluminum extrusions
Hulls and superstructures
Helicopter landing platforms
Marine and transport structures
Aluminium lithium alloys find use in aero space application as desired properties
can be achieved with reliability.
9.Friction surfacing and best applications
Friction surfacing uses a consumable mechatrode and when axial force and rotation,welding speed are applied,desired deposit is made on the substrate.
Aluminium,tool steels,stainless steel,titanium can be deposited on different substrate materials preferentially.Many industrial applications in electrical,automotive,Marine etc can be conceived for this process.Some reputed suppliers provide different capacity machines for industrial use.
10.Friction stir welding developments
Electric vehicles parts can be manufactured profitably by special purpose friction friction stir welding system.
Best application for friction stir welding