Q: We would like to decrease the development time for new MIG welds. Is there a way to pre-calculate wire-feed speed, travel speed and voltage, to get us close before we strike the first weld?

A: Yes it is possible to calculate starting wire-feed speed and travel speed. This is a very common question from manufacturers welding with solid wire or flux-cored wire. Most welding professionals know the wire-feed speed (WFS) where a process runs well based on their experience, or can quickly get WFS from manufacturer's recommended procedures. However, determining how fast to travel for a particular size weld bead ends up being an iterative, time-consuming process. By understanding a few concepts and doing some math with a few simple formulas, we can determine at least a good starting point for a welding procedure that produces the desired weld.

Deposition rate — It is essential to recall that Deposition Rate is directly proportional to the speed at which a particular wire diameter emerges from a welding gun during welding. Deposition rate has nothing to do with how fast the gun is traveling nor the voltage setting on the machine. Deposition rate is simply a measure of how many pounds of wire come from the welding gun in a certain amount of time, typically measured in lb./hr. If wire-feed speed increases, deposition rate increases. We also understand that if we maintain the wire-feed speed and change to a larger diameter wire, deposition rate will increase as well. Armed with this understanding, calculating deposition rate ends up being a very powerful exercise that gives you a number that can be used to calculate key welding parameters.

Let's look at the formula and an example: