Welding is one of the most essential and standard industrial processes, with the automotive sector leading the pack. It is also one of the processes that in the past was manually intensive. However, using the human workforce for welding processes took a turn for the best from the mid-20th century after introducing welding robots or automated welding.
The use of welding robots over manual welding offers industries many advantages. The most notable are improved production quality, higher productivity, lower operating costs, and better throughput.
Finding the correct welding equipment for the proper welding process is challenging, especially for those using a welding robot for the first time. However, once you determine the welding processes required by your manufacturing applications, it gets easier to identify the right welding robot.
Types of Welding Processes
There are several welding processes, with each one of them having its benefits and limitations. Below are some of the most common robotic welding processes.
1. Arc Welding
Arc welding, one of the most common welding processes, involves joining metal using electricity, unlike many others that use gas. It uses coated in flux consumable or non-consumable electrodes and direct or alternating currents. Heat temperatures in arc welding are intense, as it needs to be for melting and intermixing two parts.
The high heat intensity is risky for the human workforce, making welding robots appropriate for the process. Arc welding’s most common approaches include construction projects, steel erections, repair of heavy equipment, and welding pipelines.
2. Resistance Welding
Resistance welding is one of the most economical forms of robotic welding most ideal for long production runs and heat-treating projects. Furthermore, it helps to maintain consistent conditions.
Relative welding involves using thermo-electric processes that produce coalescence obtained from heat from work resistance to electric current. During the procedure, two overlapping sheets need to join by exerting pressure on them. Electrical current applied to sheets causes resistive heating that melts the metal, forming a weld. There are different resistance welding processes, which are:
- Upset welding
- Resistance seam welding
- Projection welding
- Percussion welding
- High-frequency welding
- Flash welding
Resistance welding is a fast operation, but each of the processes has its welding time cycle.
3. Spot Welding
Spot welding is another type of resistance welding that involves joining two thin metals with electrical current resistance. A current passing through two copper electrodes melts the two metals together before joining them. Some of the most common defects during spot welding include weld material splattering, loose material, metal cracks, or indentations, and weld asymmetrical spot marks.
The agility of a welding robot provides the welding tool with precision and consistency, helping to prevent spot welding defects. Welding robots are uniquely capable of spot welding in a way that would be almost impossible with other forms of automation.
Their flexibility allows them to reach the workpiece from any orientation, which is necessary to orient the tool to the exact location needed to perform the weld.
4. TIG Welding
Unlike other welding processes, TIG (Tungsten inert gas) welding is resistant to errors and a high-quality process. The process involves forming an arc between the metal part and a non-consumable tungsten electrode. Precision is one of the most important factors to consider when using the TIG welding process. Therefore, you must ensure that the program is very accurate when automating it.
The process also needs a manual welding booth with more space when setting up a TIG welding robot. Other essential features to consider when automating TIG welding include-
- A welding robot armed with a control system
- A safety enclosure complete with safety equipment to prevent any unwanted access during the automated operation
- A welding torch with a power source, hose package, and a feeding wire system
- Electricity, gas, coolant, or pressured air supply lines
- Adapted welding fixtures for automated positioning system
- If need be, an external cooling system
- Shielding curtains
- A fume extraction system
TIG welding is ideal for welding stainless steel, copper, and aluminum.
5. MIG Welding
MIG welding is a high deposition welding process that requires forming an electric arc between two metals that require welding and a consumable wire electrode. The process causes melting leading to the joining together of the metals.
The welding process is cost-effective, quick, and robust, making it ideal for more significant welds. Spatter is one of the limitations of using MIG welding, which makes the welding robot ideal for the process.
6. Laser Welding
Laser welding is not a standard welding process because it is relatively costly compared to other approaches. However, it is one of the best processes for complicated joint geometry processes because of its precision. Like other welding processes, laser welding involves fusing two metal plates using a laser beam.
The laser beam produces enough heat that melts the metal pieces to fill the captivity, which cools welds the two parts firmly together. The process requires ample working space and inaccessibility of components that do not need welding.
The three main types of laser welding used are gas laser, solid-state lasers, and fiber laser. Welding robots provide the high accuracy and precision required in laser welding much more than any other automation does.
7. Plasma Welding
Plasma arc welding is one of the most overlooked welding processes because of its complexity and the requirement of expensive equipment. The welding process involves the production of extremely high temperatures from ionized gases passed through a copper nozzle. It is ideal for highly flexible applications because it is easy to adjust temperatures and velocity.
Some of the most common plasma applications include putting together exhaust system components and body panels. Besides being slower than other welding processes, plasma welding also has a more significant heat input. It produces ultraviolet and infrared radiation, making it the perfect candidate for a welding robot.
Robotic welding processes are many, but the above are the most common for many of the applications across different industrial sectors. Welding robots provide safer working conditions, consistency, faster welding processes, continuity in production, and better quality, irrespective of the process.