Welding has been around for ages. One of the earliest known forms of welding is forge welding, or solid-state welding, a process in which two metal pieces are heated and repeatedly hammered to fuse them together. One of the oldest metal structures present in India, the Iron Pillar of Delhi (about 310 AD), is a product of forge welding.
Conventional welding as we know it today was developed in the 19th century after the invention of the electrical arc and acetylene gas. The earliest arc welding process that used electrodes was developed in the 1880s. During the mid-20th century, arc welding as a form of welding had a qualitative leap with the invention of GMAW, FCAW, SMAW, GTAW, etc.
In the last few decades, we have seen a lot of technological advancements, not just in the core of welding technology but also in other forms of technology involvement.
Evolution of gas welding to arc welding
Gas welding was invented after the invention of electrode arc welding but was the preferred method due to its technology and equipment being portable and economically cheaper. The switch from gas welding to arc welding started with the availability of electricity and because arc welding provided more weldability and a higher speed of welding. The evolution of arc welding started due to the higher demand for ships during WW1 & WW2.
Arc welding started by welding metals using direct current and a bare electrode. This evolved into the welding process, which uses a DC/AC current supply, its own welding atmosphere using gases, and electrodes providing flux to cover the weld.
Welding technology reducing the scope for human error
GMAW is the most common welding process which is extensively used in the sheet metal industry and automotive industry. Unlike other welding processes, the GMAW does not require a welder to supply filler metal externally while producing the electrical arc. In this process, the necessary filler wire is supplied through the welding gun along with the shielding gas supply.
One of the evolution that happened in the arc welding process was the evolution of the welding machine used. The earlier machines used for arc welding had to be manually adjusted for the voltage setting based on the material type and thickness. Now it has evolved to the stage where the welding machine will set up the necessary current and wire feed rate based on the application/workpiece. This reduces the probability of human error in the preparatory process and increases the importance of the welder’s technique.
IoT / Industry 4.0 adding analytics to welding process
IoT-based welding machines using advanced technology calculate the production efficiency, and the data collected will help develop a strategy to improve the productivity. These welding machines keep track of the daily usage (on/ off) and the consumption of gases, current, wire, etc. This helps in evaluating the efficiency of the machine as the cycle of its usage can be tracked to keep track of its lifecycle.
Robotic welding is a relatively new technology, even though the usage of robots for spot welding has been prevalent in some areas. Robotic arc welding is a fast-growing use of robots that use pre-programmed codes, a machine vision system, or both to perform the welding operation. It has many advantages, such as increased accuracy, increased productivity/throughput, repeatability, etc.
Industrial Metaverse / Virtual Reality innovations for welding
While the electronic and software advancements within welding machines have reduced the dependency on human error, the welder’s hand movement is still a critical factor, and to bring robotic-level precision to that, Metaverse training will help. Training welders in Virtual Reality / Metaverse has opened up a lot of options that were earlier not possible. With the latest advancements in sensors and virtual reality displays, one can create realistic 3D immersive lessons where a trainee can be taught not just standard welding joints, but also taught to weld on a 3D simulation of a component welded in the factory by importing the CAD drawing into the simulation.
Aspects that are not measurable in the real welding scenario, even with the modern IoT welding machines, like the welding speed, can be measured in the simulation and the quality of the output accurately predicted. Using sensors attached to real guns or using Virtual Reality to mimic the appearance of a welding gun, the dexterity of a welder can be measured with accuracy to 0.2 mm precision, and thus a weld bead can be simulated with the welding machine parameters and the welding gun movement as the inputs, and the output with quality aspects, like bead uniformity, depth of penetration, heat affected zone, porosity, spatters, etc, can be simulated.
The skill input parameters like the arc length (or stickout), weld angle, travel angle, path, and weld speed can all be measured, and therefore a defect can be accurately predicted with the simulation mathematical model. The advancements in Metaverse / Virtual Reality enable welders to understand deeply what their current dexterity skills are and in what areas they need improvement, which helps them achieve near-robotic quality in the welded output. Thus, with a combination of technologies, both productivity and quality are improved.