Page 36 - MetalForming-Feb-2018-issue

Fabrication: Welding
poor wire-feed performance, which in turn may lead to erratic arcs and excess spatter, and even cause the wire to burn back to the contact tip—all of which cause unplanned downtime.
For applications where flaking is an issue, premium noncoated wires are an option, as they generate far fewer particles and enable a longer run time between scheduled maintenance and liner and tip replacement (Fig. 7). These wires feature a proprietary coating that
Faster Is Better
While noncoated wires inherently benefit robotic applications, they are essential for the Swift Arc Transfer (SAT) process. SAT uses smaller-diameter, noncoated solid wires at fast wire-feed speeds to increase current density, which in turn can increase deposition rates. For example, a demonstration of pulsed GMAW vs. SAT showed how SAT offered travel speeds of 46 in./min., twice as fast as pulsed GMAW.
is not obvious to the naked eye.
To confirm performance, Esab worked with ISF Aachen, a German welding-research authority, to conduct a benchmark survey that compared premium noncoated wires with a wide selection of copper-coated wires. Results prove that the noncoated wire runs longer without burning back to the contact tip (more than 330 min. of continuous welding compared to 220 min. or less for copper-coated wires), requires less force to feed, increases
arc stability and reduces spatter.
Engage with the Experts
If there is one take-away for welding, production and manufacturing engi- neers, it should be that filler metals within an AWS classification offer wide- ly varying degrees of performance, and this is true whether working with solid wire, aluminum wire, stainless-steel wire, etc.
While there is no perfect filler wire, manufacturers can adjust wire formu-
This fabricator of replica race cars uses a noncopper-coated wire because it runs more smoothly and reduces issues relat- ed to clogged tips and liners. With con- sistent batch-to-batch performance, operators can set it and forget it, even after starting on a new pallet of wire.
lations to address specific manufac- turing needs (and still ensure that the wire meets classification require- ments). The best way to accomplish this is by engaging with filler-metal experts who understand your produc- tion requirements and can recommend solutions accordingly. MF
34 MetalForming/February 2018
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