I'm gonna back track on my post here and ask the question.
@TechnicAl the whole "deoxidise" thing in these Ms fillers. When it's single, double, triple etc is that because it contains 1,2,3 deoxidising elements like silicon or zirconium or does it de oxidise the steel 3 times. That makes no sense to me because Id of thought once deoxidised it's done ???????? Why the need to do it again????? Might be a stupid question and perhaps I'm the only one that doesn't know???????
True......you can only deoxidise once
The double triple etc are misnomers really.
Its the steel thats deoxidised NOT the weld. Silicon is the main dexodiant but if you put in more than 0.4-0.6% the metal becomes brittle, so they also use the Ti / Zr etc. They also work at different temperatures should the melt cool in the crucible / tundish.
The weld doesnt need deoxidising its being protected from Oxygen etc by an inert sheilding gas.