Do you need reduced spatter amounts, faster travel speeds, and improved control on your arc starts? With some training and practice, pulsed MIG welding can provide the improvements you need.
Many fabrication operators have goals tied to productivity improvements, profitability, or part quality. While there are many lean operating practices, sometimes a simple change in the welding process can be the right answer to reach these goals.
In some application pulsed MIG (aka GMAW-P) can drive those improvements and efficiency all while helping operators of various skill levels improve their welds.
Whether you are changing over to pulsed MIG from spray, standard MIG or short circuit process, the change is typically an easy one and doesn’t need a long learning curve.
Now, pulsed MIG may have a higher up-front cost. However, the long term benefits deliver a solid return on your investment.
How does pulsed MIG welding work?
Pulsed MIG is a modified spray transfer process using a power source that alternates between a high peak current and a low background current between 30 times to 400 times per second. As this switch happens, the peak current pinches off a droplet of wire and pushes it to the weld joint. At the same time, the background current maintains the arc but produces a low heat input that prevents the metal transfer from occurring—thus allowing the puddle to freeze a bit and help prevent burn-through.
This differs from the traditional spray transfer which is continuously transferring tiny droplets of molten metal into the joint. The lower heat of pulsed MIG welding has similar advantages to the TIG (GTAW) while providing good penetration, depositions rats, and fusion characteristics associated with a traditional spray transfer process.
Applications that are susceptible to weld defects or problems like spatter, burn-through or warping are good candidates for pulsed MIG.
Pulsed MIG works on thick or thin materials. For thick materials, it can minimize downtime since it generates a cooler weld puddle and the piece can me re-positioned quicker. For thin materials, it causes less burn through and warping because of the lower temperatures involved. This temp control allows you to use a larger diameter wire–up to 3/64 in which increases deposition rate and, of course, productivity.
What Are the Advantages of Pulsed MIG Welding?
Since you are still with me, what are a few of the key benefits that help you save time and more importantly, money.
- Quick and Easy Setup: There is an option to have one knob control to help welders set the parameters needed so they don’t have to be an expert (at getting a good arc).
- Directional Control: Controlling the weld pool makes it easier for welders to create consistent welds with a good looking bead.
- Spatter Reduction: Less spatter generated by the pulsed MIG process means less time spent on cleanup/grinding and the leads to a big impact on productivity and the bottom line.
- Wire Feed and Travel Speed: Faster speeds increases productivity but often come at a price–higher heat. However with pulsed MIG a lower heat is used and that also reduces distortion and burn-through. The big benefit with this one is on stainless steel.
- Adjustable Arc Cone: This is available in some pulsed MIG power sources. It helps prevent over-welding and poor fusion because the welder can tailor the bead profile to the application. Wider beads can help improve tie-in on both sides of a joint. Narrower beads offer better fusion at the joint root.
- Control Over Arc Starts and Stops: The process provides higher energy when the arc starts. This increases fusion and the energy is then reduced going into the weld bead. All of this helps prevent burn-through and increase control over the bead appearance. A pulsed MIG with a crater function allows one to bump down to cooler parameters to fill the crater properly. This eliminates the potential for cracking on materials like aluminum.
The Final Bead
We are running the Everlast PowerMTS 251Si in our shop. We have seen first hand that the pulsed MIG provides faster travel speeds, reduced spatter amounts, improved control over the arc starts and stops. Pulsed MIG is a good option for fabricators who want to improve weld quality and boost efficiency.