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Posted by on November 2, 2007, 2:31 pm
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>
>
>
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> rds4spamtar...@aol.com wrote:
> > Hi everyone
>
> > Where I work in a fab. shop, most welds are hori-vert T-fillets.
> > Typically adding end-plates to beams to make steel structurals.
> > Thicknesses - 6mm to 12mm in the web and flanges.
>
> > Showing on the machine's meters:
>
> > The "heavy beams" condition I see my workmates use is 260A, 22V.
> > Which is a high-amps dip-transfer condition.
>
> > I go to spray at typically 240A, 33V - get a nice small arc cone
> > giving good fusion and a very smooth bead.
>
> > (just found out the machine is 500A - yet to try higher power).
>
> > As power is Amps x Volts, my conditions give 50% extra fusing power...
>
> > So what does anyone reckon to these conditions?
>
> > For all partial pentration butt welds, etc, my conditions are plainly
> > the business.
>
> > But for T-fillets? Do you need the penetrating power? I've never cut
> > open a 260A 22V weld, but I suspect there is fusion between the fillet
> > and the bead. I can actually see with my spray conditions the
> > terminating plate edge melting - but is that fusion really needed? A
> > T-fillet weld is about the only one where you unavoidably rely on
> > filler metal. For butt welds and the like, with more fusing power you
> > narrow the weld and ultimately with the likes of electron-beam can do
> > without filler.
>
> > So what I am getting at - so long as the fillet is fused to the base
> > plates, is there advantage in actually keeping the heat input down and
> > just seeing it as maximal metal deposition by forcing dip transfer at
> > the conditions like 260A, 22V?
>
> > Rich S
>
> The goal of all welds "should" be to use as little heat as possible to
> reduce weld distortion and the size of the heat affected zone.
> However in modern production welding speed is often put above quality.
>
> Both approaches can achieve a strong weld.
> You have to balance the affect of the increased heat against the speed.- Hide
quoted text -
>
> - Show quoted text -
Thanks Randy
I usually go spray for the following reason:
As many fillets are 6mm leg length (1/4-inch), which is often small
for the section size and thickness, and this leg length is the natural
size of a weld bead done in spray at 240A, 33V (at the power source)
going for good fusion (run-rate such that arc landing just at the tip
of the weld pool), I use the spray conditions happily. No spatter and
you can bet your bottom dollar the weld is at least as strong as the
6mm leg-length specified fillet size (fusion would increase strength),
so happy with these fast one-straight-run small smooth spray transfer
fillets.
I'll look at keeping the heat input down for bigger fillets by using
spray. I was wondering about distortion - whether less heat is
usually better regarding distortion...
Thanks again.
Richard Smith
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>
> Where I work in a fab. shop, most welds are hori-vert T-fillets.
> Typically adding end-plates to beams to make steel structurals.
> Thicknesses - 6mm to 12mm in the web and flanges.
>
> Showing on the machine's meters:
>
> The "heavy beams" condition I see my workmates use is 260A, 22V.
> Which is a high-amps dip-transfer condition.
>
> I go to spray at typically 240A, 33V - get a nice small arc cone
> giving good fusion and a very smooth bead.
>
> (just found out the machine is 500A - yet to try higher power).
>
> As power is Amps x Volts, my conditions give 50% extra fusing power...
>
> So what does anyone reckon to these conditions?
>
> For all partial pentration butt welds, etc, my conditions are plainly
> the business.
>
> But for T-fillets? Do you need the penetrating power? I've never cut
> open a 260A 22V weld, but I suspect there is fusion between the fillet
> and the bead. I can actually see with my spray conditions the
> terminating plate edge melting - but is that fusion really needed? A
> T-fillet weld is about the only one where you unavoidably rely on
> filler metal. For butt welds and the like, with more fusing power you
> narrow the weld and ultimately with the likes of electron-beam can do
> without filler.
>
> So what I am getting at - so long as the fillet is fused to the base
> plates, is there advantage in actually keeping the heat input down and
> just seeing it as maximal metal deposition by forcing dip transfer at
> the conditions like 260A, 22V?
>
> Rich S