Hi,
I'm welding Galvannealed steel plates of 1.4 mm thickness, which after welding need to be painted by e-coat.

During welding, a thin "white" layer is formed around the seam; then once painted, there are several "yellow stains" which looks like Silicon precipitation issue but in a high amount. My assumption is that this is caused due to my wire filler composition.
Process description is as follows:

100% robotic MIG
Welding type: Fronius CMT (Cold Metal Transfer)
Robots: Motoman
Welding speed: 23-25 in/min
Gas: 100% CO2
Material: 1.4 Thickness, Galvannealed
Coating Layer Thickness: 7 microns
Filler Metal: ER70S6

Does anyone have experience in this issue?, any recommendations to avoid the formation of those "yellow stains"?

Thanks in advance