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When to consider a move to pulsed MIG welding

From reduced spatter and rework to increased weld quality and productivity, the benefits of switching to pulsed MIG welding can help manufacturing operations reach their productivity goals and save money.

Pulsed MIG welding is a modified spray transfer process that helps reduce spatter and cleanup.

Because of the numerous benefits of the process, many industries are converting to pulsed MIG welding. So how do companies know when to make the switch? It’s a good question, and one that should lead to several others. Read on to learn how manufacturers can determine if pulsed MIG welding is a good fit that can deliver results.

Before diving in, though, let’s start with a quick definition: Pulsed MIG welding is a modified spray transfer process. The welding power source rapidly switches the welding output between high peak currents and low background current. The peak current pinches off a spray transfer droplet and propels it toward the weldment, which helps create proper fusion. The background current maintains the arc, but it is too low for metal transfer to occur.

Because the weld pool cools slightly during the background cycle, it allows for welding in all positions on thin or thick metals. It also allows operators to run faster wire speeds while keeping a clean arc and bead profile, which reduces spatter and cleanup.   

Pulsed MIG welding delivers benefits that result in time and cost savings in the right applications. Operations that are now using constant voltage (CV) MIG welding with solid wire or metal-cored wire are good candidates for conversion to pulsed MIG. When considering the switch, manufacturers should ask these six common questions.

No. 1: Do post-weld grinding and cleanup cost too much time and money?

If an operation wants to save time and money by reducing non-value-added work, such as post-weld grinding and cleaning, pulsed MIG welding can deliver. With pulsing,

Operations that are using constant voltage MIG welding with solid wire or metal-cored wire are good candidates for conversion to pulsed MIG welding.

operators can use the entire wire speed range without entering globular transfer.

This is a benefit for material thicknesses where conventional CV MIG welding would transition to a globular transfer, which results in extreme spatter, poor arc characteristics and the potential for rework. With pulsed MIG welding, operators can run globular transfer wire speeds and keep a clean arc and bead profile. This reduces spatter, plus the time and money spent on cleanup.

No. 2: Is new welder training eating up a lot of time?

Because pulsed MIG welding is generally an easy process to learn and use, it can help operations train new welders faster. Pulsed MIG systems are designed with synergic control that offers ease of use for welders of all skill levels. Easier process setup translates into time savings and better weld quality because it helps ensure operators are using the right parameters for the job.

As an example, Accu-Pulse technology from Miller, available on Deltaweld system power sources, provides a more forgiving arc and a 28 percent wider operating window when compared to CV MIG welding. This helps welders of many skill levels produce quality welds.

No. 3: Is increased productivity a goal?

Compared to standard spray transfer welding, pulsed MIG welding typically delivers an increase in wire feed speed to match welding amperage. As a result, more weld metal goes into the joint, which can increase productivity. This is in addition to the other benefits of pulsed MIG – the ability to reduce spatter, distortion and burnthrough – that can also help operations improve throughput and productivity and spend less time on non-value-added activities.

No. 4: Are distortion and burnthrough problems part of the welding operation?

Problems with weld quality such as distortion or burnthrough can waste materials and cost operations lots of money. This can be especially true with operations that weld a lot of aluminum, which can be more sensitive to issues regarding heat input in the weld.

Because pulsed MIG welding allows wire feed speed to be increased to match welding amperage, travel speeds also increase. Travel speed is one of the main drivers of heat input – when travel speed goes up, heat input goes down. The higher travel speeds of pulsed MIG welding help reduce heat input, which helps reduce distortion and burnthrough.

No. 5: Is out-of-position welding common in the operation?

Pulsed MIG welding delivers better weld quality and puddle control when welding out of position with solid wire or metal-cored wire. This results in less parts handling and helps reduce operating costs.

No. 6: Does the operation frequently involve welding aluminum?

Pulsed MIG welding can be an excellent option for thick and thin aluminum because it generates a cooler weld puddle.

As stated, pulsed MIG welding can provide benefits for aluminum because of the ability to increase travel speed and lower heat input. Aluminum transfers heat away from the weld at a faster rate than many materials, such as steel, making it more difficult to establish a weld puddle. And because the material has a relatively low melting point, it’s prone to burnthrough and warping on thinner sections where there simply isn’t enough mass to transfer the heat. Pulsed MIG welding can be an excellent option for thick and thin aluminum because it offers increased control of the weld puddle.

While not every welding application is well suited to pulsed MIG welding, the process can deliver benefits for many manufacturing operations. If the operation doesn’t already have pulsed MIG-capable welding power sources, it may require an investment in new equipment. But the move can quickly provide a return on that investment through improved productivity, reduced rework, and easier setup and training.

Miller Electric Mfg. LLC