Metals are among the most durable materials on the face of the planet. As such, it has taken noteworthy developments in engineering to mold and shape metal into the machine parts and fixtures you see and use daily. One of the steps employed in metal construction is welding, a process in which a worker melts one piece of metal with concentrated heat on a select spot and then bonds it with a corresponding metal piece. Over time, inventors have developed various methods to weld two or more pieces of metal together.
The three most common types of welding are MIG, TIG and stick. Each of these methods serves a variety of welding applications. The following article covers these and other welding types and definitions.
Metal inert gas (MIG) welding is a form of manual arc welding for heavy metals, alternately known as gas metal arc welding.
WHAT IS MIG WELDING?
MIG welding is a metal-bonding and metal-shaping process that sends an electrode through a tool gun and applies it to corresponding metal surfaces. To prevent contamination, the welding gun employs a protective gas that shields the weld area. The MIG process is an easy and accessible welding process for garage-based metal workers and hobbyists.
The process works on metals that range from 24-gauge to half an inch thick. MIG welding is popular among metal-working novices because it is a more straightforward technique to learn and master. The MIG wire does not protect metal services from rust or corrosion. Therefore, clean and brush down bare metal parts before a MIG application. To ensure a pure flow of the electrical wire, only use clean metal in the process.
MIG WELDING APPLICATIONS
MIG welding is one of the methods most commonly used in heavy-duty arc welding projects. Some of the metal components that make up your city’s sewage or water system are the result of MIG welding. The process is standard for pipe welds. As such, the water you rely on for drinking, cooking and sanitation comes through pipes that would not be possible without MIG welding.
Due to the heavy-duty nature of the method, MIG welding is a typical technique in hard facing, which entails welding rough materials onto base metals. You have MIG welding to thank for some of the parts you see on tractors, cranes and other types of rolling stock.
MIG welding has also been essential in the preparation and assembly of the nation’s railroad tracks. Thanks to the method’s ability to join thick metal pieces together with unbreakable strength, MIG welding has been responsible for railways and public streetcar tracks that rarely require maintenance. As such, MIG welding is a chief facilitator of transportation and commerce.
The auto industry also relies on MIG welding. At the factories where workers prepare and assemble auto parts into finished vehicles, they use MIG welding for the heavier metals and equipment. Additionally, MIG welding is responsible for making the factory equipment you see along production lines. MIG welding is also a popular method at auto repair shops.
Tungsten inert gas (TIG) welding is a manual arc welding process for heavy metals, alternately known as tungsten gas arc welding.
WHAT IS TIG WELDING?
TIG welding is a metal-bonding process that employs a tungsten electrode to join one metal surface to another. During the process, argon or helium gas forms a protective shield on the applied surfaces against oxidation and other air-bound contaminants. Applications that use helium gas are also called heliarc welds. Most TIG applications rely on a middle metal. Exceptions to the rule are called autogenous welds.
The essential difference between MIG and TIG welding is that the former relies on an ongoing wire feed, whereas the latter relies on welding rods that you direct into the weld puddle.
TIG WELDING APPLICATIONS
TIG welding plays a vital role in the automotive industry, where the process is effective at bonding metal parts together for the construction of cars, vans, trucks and SUVs. The tungsten electrodes work well in the factories where workers assemble engine parts from individual pieces of metal, as well as in the plants where auto-body parts get prepared for the assembly lines.
TIG welding is also essential in the construction industry, where the equipment gets transported to worksites and used in the preparation of parts for buildings and public monuments. Many of the buildings you see along the streets and thoroughfares of your community have been the work of construction crews that rely heavily on TIG welding.
The shipping industry also employs TIG welding. The process makes it easier for shipbuilders to join shaped metal parts together for ships like aircraft carriers or cruise liners. If you have ridden a passenger ship or sailed overseas while serving in the U.S. Navy, tungsten electrodes have likely welded the body of each ship in full or in part.
TIG welding is furthermore crucial in the aerospace industry, where the process brings together the parts that comprise NASA’s rocket ships and space shuttles.
Stick welding is a form of hand-driven arc welding used on a range of metals. The process is alternately known as shielded metal arc welding and flux-shielded arc welding.
WHAT IS STICK WELDING?
Stick welding is a metal-bonding method in which a flux-covered consumable electrode bonds two metal surfaces together. During the stick-welding process, a direct or alternating current forms between the electrode and the adjoining metal surfaces. Vapors that result from the fading electrodes generate the shielding gas. People commonly use the process to weld steel and iron, as well as copper, nickel and aluminum.
STICK WELDING APPLICATIONS
Stick welding can help workers complete tasks large and small in virtually any location. For outbound applications, the process is convenient because the equipment required is portable and easy to transport for on-call repair tasks. Therefore, stick welding often comes into play in otherwise hard-to-reach locations and remote public buildings.
Stick welding is also common at outdoor construction sites, where the process makes it easy for work crews to assemble and modify metal parts on the spot. The flux-covered electrodes are wind-resistant, which makes the process convenient in various environments. When a disaster strikes, stick welding is often the method used to repair damaged metal fixtures.
In remote settings, stick welding is one of the most convenient types of arc welding. When workers assemble temporary structures for county fairs and carnivals, stick welding can strengthen and fortify the support beams of tents and fences. For communities that live off the grid, stick welding is one of the most reliable methods for metal repair and construction.
The portability and ease of stick welding have also made it one of the preferred methods among hobbyists and independent craftspeople. Since the approach works with a broad variety of metals, jewelry makers sometimes use stick welding.
ALL OTHER TYPES OF WELDING
Throughout most of the industries that employ metal construction, the processes of MIG, TIG and stick welding are the most widely used due to the power, efficiency and versatility of each method. However, numerous other processes can also weld two or more pieces of metal together. So how many types of welding are there? There are many different approaches to welding, including the following 12 methods, a few of which are somewhat related to the three most popular types.
Flux-cored arc welding (FCAW) is a method of metal-bonding akin to MIG welding, as both use a continuous electrode. However, FCAW requires a tube-shaped wire rather than a solid one. The technique is suitable for both indoor and outdoor use, as long as the wires have adequate shielding. FCAW is one of the more efficient approaches to arc welding because it uses most of the electrode that goes into the process. Thanks to the shape of the flux-cored wire, shielding gas is not necessary with FCAW. The method leaves little debris and therefore entails only a small cleanup process after completion.
Electronic beam welding (EBW) is a metal-joining method where electron rays get fired at high velocity to join one surface of metal to another. When the ray hits its target, the affected spot melts just enough to fuse the adjoining piece into place. EBW welding plays a role throughout the industrial sector. The method is especially useful for automotive and aerospace manufacturers, who employ EBW welding to fuse many of the metal parts used in cars, trucks, planes and spacecraft. Due to the vacuum-based nature of EBW welding, the process is safe for emergency work in evacuated buildings and houses.
Atomic hydrogen welding (AHW) is an old method of metal bonding that has mostly fallen by the wayside in favor of more efficient and effective methods, such as gas metal arc welding. One area in which AHW is still common is in tungsten welding. Since tungsten is highly sensitive to heat, AHW is safe for this process. American chemist Irving Langmuir developed this process following his discovery of atomic hydrogen.
PLASMA ARC WELDING
Plasma arc welding, invented in the mid-1950s, is a method similar to gas tungsten arc welding. The process employs an electrical current, which travels through a tiny nozzle that cuts through a shielding gas. When you need to weld small areas on a metal surface, plasma arc welding allows for pinpoint accuracy. Plasma arc welding is ideal for welding projects in severe temperatures, as this creates firmer and tighter welds. Aircraft manufacturers use this method, as do independent craftspeople for a range of projects.
Electroslag is a process of fast welding that was an innovation during the 1950s. Electroslag welding bonds heavy metal pieces for use in machines and industrial equipment. The process takes place in a vertical position that allows for a clear-eyed view of the work as it takes shape. The method gets its name from the copper water holders contained inside the tool used for electroslag welding. The water stops liquefied slag from seeping into other areas during a welding session.
SUBMERGED ARC WELDING
One of the less frequently used forms of metal bonding is the process of submerged arc welding, which is only suitable for stainless steel and other metals rich in iron. The process allows for the use of both automatic and semi-automatic means, which renders it quick and efficient. Despite the speediness, the process requires a flux to shield the metal when the welding takes place, hence the name “submerged.” With this cover, people can complete their work without the risk of splatter. Therefore, submerged arc welding is a safe practice for independent craftspeople.
Carbon arc welding (CAW) is a bonding method that joins metals by applying temperatures that exceed 300 degrees Celsius. In CAW welding, an arc forms between the metal surfaces and the electrode. The method was once popular, but in recent decades, twin-carbon-arc welding has superseded it.
Oxy-fuel welding is a process that employs liquid fuel and oxygen to weld metal into shape. French engineers Edmond Fouché and Charles Picard invented it at the turn of the 20th century. The oxygen-generated temperature employed in the process gets applied to concentrated areas of a metal surface. Oxy-fuel welding takes place within an indoor environment.
Resistance spot welding is an arc welding method in which heat bonds metal surfaces. Resistance from electrical currents generates this heat. RSW welding belongs to a group of welding methods known as electric resistance welding.
RESISTANCE SEAM WELDING
Resistance seam welding is a method that generates heat between the faying surfaces of metals with similar properties. Seam welding starts on one side of a joint and works its way to the other end. The process depends on twin electrodes, typically made of copper.
As a form of spot welding, projection welding is a process that localizes heat in a specific area for positioning. The process is common in projects that involve the use of nuts, studs and other threaded metal fasteners, as well as in crossed bars and wires.
Alternately known as contact welding, cold welding is a method that joins surfaces without any heat or melting involved.
For more than 30 years, Astro Machine Works has welded metals for the products and machinery used in a variety of industries. As Pennsylvania’s primary welding specialists, our team has served the aerospace, electronics, telecommunications, food processing and pharmaceutical industries, among others. To learn more about our welding services, contact us today to speak with our representatives.