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AGA CW Handbook A4_32130-UK
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20 the effect of shielding gas on productivity 4.5. high-productivity mig/mag
weld
ing
the single most important factor increasing productivity is the deposi- tion rate. in mig/mag
weld
ing
, it is 3–5 kg per hour on the average. however, it is often possible to increase the deposition rate up to 7–10 kg per hour without investing in new equipment. by using unconventional
weld
ing
parameters, you can widen the
weld
ing
operating range, which is directly correlated with productivity as evident from the chart above. based on the above, aga has been de- veloping a high-productivity
weld
ing
method,
rapid
processing ® . the developed techniques are forced short arc, which aims at increasing
weld
ing
speed, and rotating spray arc which increases the deposition rate in the
weld
ing
of thick materials (e.g. 15–20 mm). depending on the case, a
weld
ing
speed of more than double that of regular mag
weld
ing
can be achieved with the forced short arc. this technique can be utilised using the current equipment in both mecha- nised and manual
weld
ing
. 4.5.1 example of a rotating spray arc application
weld
ing
application: robot
weld
ing
of a bus chassis component, pa (flat) a very high deposition rate can be achieved with rotating spray arc, up to 20 kg per hour. this requires that the wire feeding speed can reach a maximum of 35–40 metres per minute. a new, reliable wire feeder and a high-power power source must often be acquired. in practice, this almost always requires mechanised
weld
ing
. mison ® 8 is the best shielding gas for both techniques; its low carbon dioxide content provides a stable arc, only a little spatter
weld
ing
itself onto surfaces, a low-bead
weld
with a smooth fusion with the base material and low surface oxidation. when the high-productivity
rapid
processing ® techniques are used, more ozone is generated. for this reason, it is important to use a shielding gas which limits the generation of ozone for the sake of the
weld
er’s work environment. 4.5.2 example of a forced short arc application during the manufacturing of a semi-trailer, some of the exterior joints were
weld
ed as intermittent
weld
s. in practice, it rather quickly became evident that during rain, rusty dirt flowed over painted surfaces from the un
weld
ed segments of the joint in question. due to this, it was decided to
weld
the entire joint, which increased the length of the
weld
from 11 metres to 16 metres. through the implementation of the
rapid
processing ® technique,
weld
- ing speed could be increased by so much that despite the increased
weld
length, the
weld
ing
time was reduced from 29 minutes to 20 minutes. lower
weld
ing
costs and better quality with the
rapid
processing ® technique previous process
rapid
processing ®
weld
length 2 x 400 cm 1 x 400 cm air gap 6 mm 5 mm sheet thickness 10 mm 10 mm filler material cored wire solid wire root gap area 60 mm 2 50 mm 2
weld
ed filler material 2.0 kg 1.6 kg total
weld
ing
time cored wire solid wire root gap area 40 min 10 mm the
rapid
processing ® technique allowed the increase of
weld
ing
speed, reduc- tion of filler material consumption and reduction of product
weld
ing
costs. at the same time, side penetration was improved and deformations were reduced. shorter
weld
ing
time despite longer
weld
length by using the
rapid
processing ® technique
weld
length/product
weld
ing
speed
weld
ing
time (cm) (cm/min) (min) intermittent
weld
, mag 1100 40 29 continuous
weld
, mag 1600 40 42 continuous
weld
,
rapid
rocessing ® 1600 90 20
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