Room for advancement
- Created: 2017-06-06
Reach welding automation goals with advanced processes
by Justin Durik, welding engineer, and Caleb Rosera, product manager, Miller Electric Mfg. Co.
Companies invest in welding automation for many reasons. They may want to improve productivity, address quality issues, uncover efficiencies and cost savings, or address a shortage of skilled welders. The benefits automation can provide to operations with repeatable parts or high throughput are well documented.
But if companies only use traditional constant voltage (CV) MIG or standard pulsed MIG welding processes in their automated welding system – instead of advanced wire processes that deliver adaptive arcs – they may not be gaining the most benefits from the investment.
There are several reasons why companies may overlook advanced welding processes. They may not understand the advantages, including faster travel speeds, lower spatter levels and less heat input. They may view it as a risk to switch from traditional welding processes that are already qualified. Or, they may be intimidated by changing to processes they know less about.
These hesitations can be overcome with training and by experiencing some of the benefits of these advanced processes firsthand. In fact, implementing advanced welding processes featured on power sources already in use – or investing in newer machines with these capabilities – can help companies take their automated welding operations to the next level.
Questions to answer
Advanced welding processes can provide better results in the right application. When investing in a new welding system with these processes or switching from CV MIG or standard pulsed MIG welding to an advanced process in an existing system, consider some key questions.
What are the goals of the welding operation?
In answering this question, first look at the issues to be solved and then select the advanced welding process that is best suited to resolve those challenges. For example, is the company looking to gain any of the following? Increased travel speeds? Better control of heat input? Reduced spatter? Improved productivity or throughput? Improved quality?
For each of these issues or goals, there is an advanced welding process solution that can provide benefits. Companies must know what they want to accomplish to make the best choice for the application and their short- and long-term goals.
What is the material type and thickness?
Advanced welding processes work especially well on thinner materials because the arc allows for better control of heat input. They help reduce spatter and improve travel speeds, which, in turn, helps reduce heat input and minimize distortion. These factors are critical on certain materials. When welding stainless steel, for example, reducing spatter and distortion helps save time and money in cleanup and reduces the chance for material waste.
What is the part repeatability?
Ideally, parts coming from upstream in the operation should be consistent with a low degree of variation, but this is not always the case. When parts aren’t perfect every time, the technology and improved arc control provided by advanced welding processes can help compensate for discrepancies, such as poor part fit-up or poor joint preparation.
Don’t be intimidated by the terms “advanced processes” or “advanced arcs.” Power sources that provide these technologies have interfaces designed for ease of use.
As advanced welding processes continue to evolve, they improve control over the arc. Some power sources make synergic adjustments – the operator may adjust one knob while the machine simultaneously adjusts multiple parameters or settings to produce the desired arc characteristics. This simplifies setup and prevents the automated system from welding with less-than-ideal welding parameters.
Power sources available today, including the Auto-Continuum advanced MIG welder, offer numerous advanced process options.
Versa-Pulse. This next-generation advanced pulse process offers the most benefits for automated welding applications, delivering exceptionally fast travel speeds because it has a shorter arc length than other advanced processes. This process uses a short-circuit event after each pulse, which means the waveform can be adjusted to allow for use of lower current when clearing the short.
It also has a tighter arc that results in lower voltages, providing low heat input and low spatter. This makes it especially beneficial when welding specialty joints, structural tube and very thin materials, such as 12-gauge and thinner materials commonly used in the automotive and transportation industries.
Accu-Pulse. Due to its wide operating range and controllability in all welding positions, an advanced pulsed MIG process is often the most popular of the advanced processes in automated welding for industrial applications. It can run a shorter arc length for lower voltages than traditional processes while staying above the spray transfer threshold. The result is less heat input, better arc control and faster travel speeds.
Where most standard pulsed MIG processes adapt to changes by varying the pulses per second, advanced pulsed MIG processes change other variables, which provides faster responses to changes in the arc. This allows for varying welding parameters without sacrificing the weld profile, quality or mechanical properties of the completed weld. Advanced pulsed MIG also allows the most wire and gas combinations of the advanced process options.
Regulated Metal Deposition (RMD). This modified short-circuit MIG process is a good solution for resolving poor part fit-up and for parts that need minimal heat input. However, reduced travel speeds limit the use of this process in some applications.
In RMD, the welding system anticipates when the short circuit will transition to the arc, then reduces the welding current to create a consistent metal transfer. This precisely controlled metal transfer provides uniform droplet deposition, making it easier for the automated welding system to gain good weld pool control. In addition, the reduced current reduces spatter production.
A good choice
Companies that invest in automated welding systems can reap many benefits, from improved efficiency to reduced variances in part quality. Utilizing advanced welding processes can take those results to the next level – for even greater productivity, weld quality and cost savings.
Advanced welding processes help address issues with distortion, spatter, travel speeds and other factors, which can minimize rework, increase production and make for a more competitive operation. No matter the challenge or goal in the welding operation, there is likely an advanced welding process that can address it and result in improvements.
Researching the right choice and consulting a trusted welding distributor or equipment manufacturer can help companies make an educated decision that delivers short- and long-range results as well as profitability.