Welding is a process by which, coalescing materials like thermoplastics or metals are seamlessly joined for different applications. The entire process is nothing but a controlled and ordered application of both pressure and heat. Like everything, the welding process has also evolved over the years. From heating iron, it became something more complex and efficient in joining metal alloys. In FMB, laser cutting is ruling over metal integrity without raising any questionable eyebrows in case of profit. Laser cutting is usually the first step of the process before it continues down the line to undergo metal bending, metal rolling, and other types of metal fabrication in stainless steel, mild steel and aluminium.
Throughout the evolution, welding became more and more useful in different industries, which led to the adoption of different methods of welding as needed. For industrial use of welding, it is of utmost importance that one understands these different methods of welding before taking any decision.
In 1903, Gas welding was developed by Edmond and Charles, two French engineers. It was also known as Oxyfuel or Oxyacetylene welding because the welding required combining pure oxygen with fuel gas to increase flame’s temperature around 35000 Celsius.
Gas welding is surely one of the ancient welding methods, which is still being used in tube and pipe welding, as well as some repairing industries. Even metal artists nowadays use it to build their metal sculptures.
In this method, electric current is applied upon the surface in order to generate intensive heat. But before applying the electric current, this welding involves applying force to the adjacent surface.
There are different variations of this technique, like seam welding, spot welding, butt welding, upset welding, projection welding, flash welding, etc.
EBW (Energy Beam Welding)
This is a rather complex welding method that involves firing high-velocity electron particles on the material. The entire process needs to happen in total vacuum.
The energy that comes with the electrons is transformed into heat. The heat in terms melts the welding material and allows them to get fused together.
Common used EBW techniques are electron beam welding and laser beam welding.
Solid State Welding
In solid-state welding, no filler material is used. In this process, the temperature is increased up to the melting point of the material. It depends on the trifecta of time, pressure, and temperature, individually or just in a tandem to combine the metals without needing to melt them down.
Although it’s an old form of welding, many new welding methods are based on it.
Arc welding usually involves using electrodes and power supply to form the welding arc between the material being welded (mostly metal) and the electrode, to melt down the material and join them together.
Most common type of Arc welding is Stick welding, TIG, and MIG welding. And all of the methods are divided into two groups, consumable & non-consumable method.
Consumable Electrode Methods:
- 1. MIG Welding (GMAW or Gas Metal Arc Welding)
MIG (Metal Inert Gas) welding involves combining metals with a wire, connected to an electrode current. This wire gets through the welding stick that is shielded by any inert gas.
Advantages of MIG Welding includes lower degree of precision and ease of use. But MIG welding very much sensitive to the external factors such as dust, rain, wind, and even voltage and wire speed.
Porosity and Dross are two of the most common problems with MIG welding. If they are nor taken into consideration, the joint might become weaker than TIG welding.
However, MIG is much easier to gain mastery on as the electrodes automatically fed through torch. But unlike TIG welding, MIG only needs the welding gun to move across the place being welded.
This welding is mostly used in automotive repairing as it’s capable of giving you a sturdy, strong weld that is done properly and able to withstand the larger forces, giving you utmost versatility as well as strength required for such application. Apart from automotive, MIG welding also comes in handy for plumbing, robotics, construction, and the maritime industry.
- 2. Stick Welding or Shielded Metals Arc Welding (SMAW)
Stick welding is a manual process that uses consumable electrodes that are coated in flus and used for laying the weld. The process is named stick welding because welding rods or sticks are required as filler material and the flux.
Stick welding is comparatively a cost-efficient welding solution, which requires the least amount of equipment. But due to cracking, shallow penetration, vulnerability to severe weather, and porosity hamper the quality of Stick welding. Best use of Stick welding is in construction, automotive, plumbing, refrigeration, etc.
- 3. FCAW or Flux-Cored Arc (FCA) Welding
FCAW is quite similar to MIG welding, apart from these facts that FCAW uses a unique flux filled tubular wire and depending on the filler, shielding gas isn’t always mandatory.
Although it’s an easy technique to learn, the expense is gigantic and that’s why FCAW is not suitable for small production.
Flux-Cored Arc Welding is quite similar to MIG, except for the fact that it uses a unique tubular wire filled completely with flux and the shielding gas is not always needed, depending on what filler is being used. FCAW is notable for being extremely inexpensive and easy to learn, although there are several limitations in its applications and the results are often not as aesthetically pleasing as some of the other types of welding methods.
- 4. SAW or Submerged Arc (SA) Welding
SAW is a common type of arc welding, mostly used on nickel alloys and ferrous steel. Due to the low emission of welding arc lights and fume, it is much safer than others.
The whole welding process takes place beneath the flux and that’s why it is referred as Submerged Arc (SA) Welding.
Non-Consumable Electrode Methods
- 1. TIG Welding or Gas Tungsten Arc Welding (GTAW)
Tungsten Inert Gas or TIG is a process that is known for utilizing a non-consumable tungsten electrodes with the inert gas (mostly argon). As Tungsten is a rare and provides a high purity, the welding quality is quite impressive. That’s why TIG welding is the most popular welding technique used these days.
With TIG welding, temperature is raised by running the electric current via any tungsten electrode, which creates an arc to be used for melting metal wire and create weld pool.
- 2. ESW or Electro-Slag Welding
ESW is very efficient and mostly used in thick and nonferrous metals. The technique requires high skills and extreme precision. Mostly, ESW is used in aerospace and maritime applications.
- 3. AHW or Atomic Hydrogen Welding
AHW involves placing 2 tungsten electrodes inside a hydrogen atmosphere. Then the Hydrogen molecule breaks up and combines again with an explosion. The explosion cause the heat to reach 3000 degree Celsius.
- 4. CAW or Carbon Arc Welding
Carbon Arc Welding is the first ever arc welding process to be invented. But recently, it is being replaced by more efficient and time-0saving welding methods to save production cos, time, and effort. This welding process requires heating metal with a Carbon electrode (non-consumable). Gradually the temperature increases up to 3000 degrees Celsius.
- 5. EGW or Electrogas Welding
EGW is somewhat similar to ESW except for the fact that EGW doesn’t need any pressure. Besides, in EGW is not extinguished. The main use of Electrogas welding is in shipbuilding industry and storage tank factories.
Before making the decision, it’s important to know what type and method of welding is profitable for you. Remember, a wrong decision about the welding process can be the game changer for you. So, it’s always better to research the welding method properly before implementing it in your workshop.