The Pros & Cons of Automated Welding

Automated welding has the potential to provide enormous gains in the productivity and profitability of fabricators.

Successful application of automated welding systems can offer tremendous benefits, including: 

  • Increased output
  • Improved quality and accuracy
  • Lower costs
  • Greater repeatability 
  • Reduced consumables
  • Reduced labour requirement
  • Improved safety
  • Reduction of scrap and rework
  • Simplicity of operation

As fabricators become increasingly challenged by escalating labour costs, skills shortages and global competition, these are benefits that a modern fabricator simply cannot afford to ignore. The most innovative fabricators are now applying welding automation as a matter of routine.

 What are Welding Automation Technologies?

Welding automation technology’ is a generic term used to describe a wide range of devices—some simple, some highly complex—designed to automate repetitive welding tasks, improve welding accuracy, increase weld quality, improve repeatability and augment the skills of welders.

An experienced welder makes continuous, instinctive, split-second decisions on travel speed, torch angle, oscillation, heat input, voltage and wire feed. Welding is not a binary process. By its very nature welding is a multi-variable problem which must be solved in real time. Human beings have proved to be outstandingly adept at this, however the high cost of skilled welders has driven enormous interest and advances in welding automation technologies ranging from robotics to adaptive seam tracking.

Dramatic Productivity Gains in the Right Applications

While the joining of metals is conceptually simple, welding has evolved to become one of the most complex manufacturing processes.

It’s not uncommon for companies who are unaware of advances in welding automation to spend hundreds of thousands (and in some cases millions) of dollars on materials handling equipment and automating assembly, while overlooking the potential to achieve dramatic cost savings, productivity increases and quality improvements by combining transformative new welding processes such as K-TIG and Friction Stir with modern welding automation equipment.

The cost of such equipment is typically immaterial relative to the order-of-magnitude cost savings which can be achieved in suitable production applications or significant projects.

Manual Welding has its Place

Superb quality can be achieved by a skilled manual welder, and for some applications, you just cannot beat manual, hand-held welding.

Welding mechanisation and automation lends itself to production fabrication, where repeatability is key. Large investments in sophisticated welding automation technologies are unlikely to make sense for job shops handling low volume unique projects. Having said that, even single-person fabrication businesses can benefit significantly from basic welding mechanisation such as rotators, positioners, seamers, welding carriages combined with a high productivity welding process. 

Fully or Semi-Automatic Automation?

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Welding automation falls into two major categories: semi-automatic welding and fully automatic welding.

Semi-Automatic Welding

Semi-automatic welding involves an operator manually loading and setting up the workpieces. An industrial control system then controls the torch, part motions and welding parameters (either pre-set or adjusted dynamically using sensors) that perform the weld. At the completion of the weld, the operator is required to remove the welded component and set up for the next weld. Semi-automatic welding is by far the most common category of welding automation, and is designed to augment, rather than fully replace, skilled operators.

Fully-Automatic Welding  

Fully automatic welding involves a machine, or series of machines (typically robots), loading a workpiece, moving the part or torch into position, performing the weld, monitoring the quality of the joint and unloading the finished product, and may also include post-weld quality inspection. Manufacturers involved in the fabrication of large volumes of precision components can achieve very significant productivity gains from fully automatic welding.

Which Welding Applications are Best Suited to Automation?

Welding applications that benefit the most from automation have one or more of the following characteristics:

  • High output is required
  • Quality and repeatability are critical
  • Weld accuracy is essential
  • Parts are identical
  • Parts have significant value
  • Welding repairs are difficult or expensive
  • Welding costs need to be reduced
  • Consumables need to be reduced
  • Labour is expensive &/or difficult to secure
  • Manual welders may be at risk
  • Scrap & rework rates are unacceptably high
  • Workshop floor space is limited

The fabrication of pressure vessels and tanks, particularly high value stainless and corrosion resistant material vessels, are examples of applications that possess almost all these characteristics and are ideally suited to semi-automatic welding automation.

Weld Integrity & Repeatability

Weld quality is determined by two primary factors: weld integrity and weld repeatability.

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Weld Integrity

Welding automation systems help to ensure weld integrity through the use of industrial weld process controllers. By combining mechanised torch or part movement (to ensure consistent travel speed – typically a critical weld parameter) with pre-set or dynamically adjusted current, voltage, arc length, weave pattern, pulsing and wire feed, complex welding operations can be performed to a higher standard than is possible with manual welding. Quality control can be built into the automated weld procedure and enforced during welding, rather than relying on post-weld inspection.

Weld Repeatability

Welding automation systems help to ensure weld repeatability through a high degree of process accuracy, and in the case of adaptive welding (see Top 20 Welding Automation Technologies), the ability to adjust welding parameters in real time in response to variations in fit-up or welding conditions. Where adaptive welding is used, parameters are typically allowed to vary only within a given range to ensure full compliance with the weld procedure.

 Increased Output

Semi-automatic and fully-automatic welding systems can significantly increase output by reducing or eliminating the reliance on people. When welding automation systems are utilised, the maximum speed of production is not limited by human endurance, concentration or hours of work.

Most partially and fully automated welding systems can outpace a skilled manual welder by a wide margin.

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Superior Weld Quality

The automation of travel speed, current and other key variables reduces the likelihood of human error in the welding process. Typically, an automated weld will only be initiated when all of the pre-determined requirements are satisfied, either through a pre-weld inspection, pre-weld scan or real-time adaptive weld sensing.

Manual welding requires a high degree of concentration over sustained periods, inevitably resulting in welder fatigue and increasing the likelihood of defects. In some cases, particularly when working with high value parts, the cost savings in scrapped parts and materials alone can justify the purchase of an automated welding system.

Greater Weld Consistency

Highly automated welding cells can perform the same welding operation repeatedly for very extended periods of time.  Indeed, assuming that weld conditions are highly consistent, a well programmed automated welding system will provide highly consistent weld quality almost indefinitely.

Welding automation allows for a much higher degree of adherence to weld procedures and quality assurance standards, and can dramatically reduce the frequency of reworking processes such as grinding, machining and re-welding.  

Reduced Labour Costs

Highly automated welding cells can perform the same welding operation repeatedly for very extended periods of time.  Indeed, assuming that weld conditions are highly consistent, a well programmed automated welding system will provide highly consistent weld quality almost indefinitely.

Welding automation allows for a much higher degree of adherence to weld procedures and quality assurance standards, and can dramatically reduce the frequency of reworking processes such as grinding, machining and re-welding.  

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Reduced Labour Cost

Complete reliance on manual human welders can dramatically increase a fabricator’s labour costs. Manufacturers must consider not just the time that welders spend producing a part, but their breaks, hours of operation, over-time, annual leave, sick leave, lost-time injuries, staff turnover, training time, daily distractions and the plethora of other factors that impact personal productivity and therefore labour cost.

Many fabricators find themselves requiring their manual welders to work overtime, or may need to employ additional contract labour to help meet demand. This can have a serious and negative impact on production costs. If products cannot be supplied to a demanding end customer, penalties may be applied and the relationship with the customer may be jeopardised. Companies with a relatively high dependence on automated welding and a relatively low dependence on manual welding are largely buffered from these impacts.

In general terms, a semi-automatic welding system will provide at least 2x the output of a skilled welder, while a fully automatic system with multiple positioners and the ability to load and unload parts can provide up to 8x the output of a skilled manual welder.

Reduced Labour Skill

The availability of skilled labour for manual welding is a significant challenge in many locations. In many western countries, the average age of welders is increasing rapidly as less and less young people choose manual welding as a career.

By way of example, the average age of the 360,000 welders in the US is now upwards of 55 and is climbing. Fewer than 20% are under the age of 35, according to statistics from the American Welding Society (AWS). In the US alone, there will be a deficit of 290,000 skilled welders by 2020 due to continuing attrition and rising demand from natural gas drillers, steel producers, automakers and other sectors. This situation is mirrored in Europe, Canada, Australia and other developed economies.

Critically, the operation of welding automation equipment requires only general machine operators, who are far more readily available, and significantly more affordable, than skilled welders.

Cost Efficiency

While the upfront capital costs of some higher end welding automation systems may be considerable, the payback and return on investment can be very rapid as a result of dramatically higher throughput, productivity, reduced labour costs, improved quality and accuracy, reduced waste and rework, reduced clean-up and other factors. 

Fabricators deploying welding automation systems can choose to either reduce the size of their workforce, or assign their highly skilled welders to critical manual operations and assign their less-skilled, lower paid operators to oversee automated welding operations.

Improved Safety

For many welding applications, worker safety can be significantly improved by introducing automating welding processes. Many welding applications, such as confined space welding, are dangerous. Almost all welding applications have the potential to cause harm from toxic welding fumes and exposure to arc-flash. Such applications can be automated and the need for human involvement largely eliminated. Automated welding systems can dramatically reduce both the probability of incurring lost-time injuries in the short term, and negatively impacting on general welder health in the long term.

Highly automated robotic welding cells introduce a potential hazard in their own right. However, this is largely mitigated by the use of several safety devices such as laser curtains, gated welding cells and the availability of numerous emergency stop buttons within easy reach of operators and supervisors.

 

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24-Hour Operation

Automated welding stations don’t need smokos. The time required to perform routine maintenance on most welding automation systems is but a small fraction of the accumulated time associated with rest periods required by manual welders.

Highly automated (typically robotic) welding processes that include materials handling capabilities can operate continuously for much longer than manual welders, including for 24 hours or more. The time and resources associated with complex employee scheduling can be reduced significantly.

Accuracy

The automation of welding procedures can dramatically improve both the accuracy of fit-up and joint geometries, and the accuracy and precision of the weld itself. Identical fit-up combined with identical welding parameters results in identical, high quality welds.

Robots in particular have very high repeatable accuracy (typically ± 0.04 mm). Robots have the ability to follow a three-dimensional path with great precision, while presenting the welding torch at the correct angle, speed and distance from the workpiece.

Reduced Consumable Costs

Typically, it is up to the judgment of a manual welder to make decisions on the fly as to how to weld to a specific standard, and to ensure compliance it is very common for a welder to oversize the weld.

A robotic welding system however, will weld exactly to the procedure which has been established, and use no more or less wire than is required for compliance. The result can be extremely significant savings in wire consumption. For example, if a manual welder welds a 5 mm fillet, where only a 4 mm fillet is required, the savings in welding wire alone will be 36%.

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