The welding transfer modes are only available for Gas metal arc welding (GMAW) or MIG welding. Transfer modes assist a lot in enhanced productivity and Quality of the welding. The modes are decided by taking note of different factors.
These include the power source, welding parameters (voltage or ampere), and the nature of shielding gas. Electrode surface, Chemistry, diameter, and tip-to-work distance also play a key role in the determination of transfer mode.
Taking all the parameters into a note, four welding transfer parameters have their characteristics and applications. The three transfer modes, including Short Circuiting, Globular, and Spray transfer mode can be done by the constant voltage, whereas the fourth and the last Pulse spray transfer mode require an advanced power source.
Below we have described these four methods along with their pros and cons.
1. Short Circuiting Transfer Mode
Short circuit transfer mode operates on the lowest parameters. They use a lesser amount of welding current and a shorter diameter of the electrode which makes it a slower process than other methods.
During short-circuiting transfer mode, a short electrical contact is developed between the Base material and the welding wire, which helps transfer metal into the joint. It occurs at a rate of 90 to 200 times per second.
This welding method is suitable for thinner metal wires in a range of 1/18 or less than this. The shielding gas used in this method is 75% argon mixed with 25% CO₂.
Pros of Short Circuiting Transfer
- Requires low amperes.
- Suitable to do in any position.
- Amazingly works on thinner sheets.
- Could be used on Thick sheets.
Cons of Short Circuiting Transfer
- Cannot create a short arc for some materials.
- It Causes Cold Lap.
- Spatter can be caused due to thickness.
- An undercut can happen.
2. Globular Transfer Mode
Globular transfer mode is that which helps transfer the density of current and doesn’t get affected by the nature of shielding gas.
However, CO₂ works in this method with all usable welding currents. In this method, the drop Diameter is mostly greater than the diameter of the electrode. This method has higher Wire speed and voltages than short-circuiting transfer mode, making it more productive.
As the productivity rate of the Globular transfer method is higher, the input rate of heat also increases.
Pros of Globular Transfer
- It uses 100% Co₂.
- It is an inexpensive process.
- It has a higher deposition rate.
- It works on both thick and thin wires.
Cons of Globular Transfer
- It can only be used in Horizontal or flat orientation.
- It can also cause spatter.
3. Spray Transfer Mode
Spray transfer mode operates on very high voltage and amperes making it a very productive method than any of the other methods. It’s a much smooth, easy, and fastest method as it produces a very stable arc that helps in fast welding.
The spray mode works by generating a spray of tiny droplets whose diameter is much lesser than the diameter of the wire. It produces a very precise weld bead and reduces the need for cleaning after the welding process.
The shielding gas used in it is a mixture of 80% argon and 20% CO₂ without being under the threat of being undercut.
Pros of Spray Transfer
- It has a good bead appearance.
- Its Deposition rate is amazing.
- It’s Spatter free and washable.
Cons of Spray Transfer
- It can’t weld thin materials.
- It has a very hot arc with limited penetration.
- It doesn’t work in any position except flat and horizontal.
4. Pulse Spray Transfer Mode
Pulse spray transfer mode works on a different method than the other three methods. The operator notices a distinguished sound when performing this method than others because of the Power source cycling.
It operates at a high peak current or voltages and a low background current. The small droplet of wire is pushed to the weld pool via peak current, whereas the lower background current doesn’t generate welding melt transfer. This cycle occurs at a rate of 30-400 times.
Pros of Pulse Spray Transfer
- The operator has a command on arc starting and stopping.
- It has lower heat input.
- It has lower chances of distortion.
- It has faster speed with lesser spatter chances.
Cons of Pulse Spray Transfer
- It requires a very highly skilled operator to weld.
- It doesn’t work much well with aluminum.
Conclusion
We have described the four methods of welding transfer mode that are only applicable in MIG Welding. Knowing which filler method works with which transfer mode speeds up the process and helps in better welding.
If you have any queries, ask us below in the comments.
