Hello,
I am trying FCAW and I want ask, what depends on the dark color that I notice in my weld?
It's a problem with parameters machine? Travel speed? I tried change my travel speed and
to increase the tension but the color does not change.
Ciao Alessio, and welcome to the Forum !
On your photograph, which shows a vertical weld which is dark at the bottom, did your weld start at the bottom - the dark area ?
My guess is, if that is the start of the weld, there is not enough flux coming from the wire at the beginning of a weld bead, and so there will be slight oxidation at that place. Then later along the bead the flux level builds up and the metal remains bright.
Did you try a different supply of wire? What brand of wire are you using?
Hello, no they are all horizontal welds. Dark area is a the end of weld. But I post a new photos, here the welds are all dark. Here I tried to change travel speed and parameters machine. I clean the weld with a grind and
cup brush. I use a helvi wire.