History of Electrode Extensions
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For nearly fifty years, it has been known that deposition rate can be significantly increased for Submerged Arc and Gas Metal Arc Welding by increasing Electrode Extension (EE).
Electrode Extension is the length of wire measured between the point of final electrical contact with the welding wire (at the end of the contact tip) and the welding arc.
The welding arc melts the wire, but the hotter the wire is when it reaches the arc, the faster the arc can melt the wire at a given amperage.
The wire within the EE is subject to preheating due to the wire's own resistance to the flow of welding current:
POWER = Current Squared X Resistance = I2R
This preheating increases with increased EE, reductions in electrode cross-section (i.e. diameter) and with increases in alloy content. In each case, wire resistance is increased.
Therefore, longer EE's increase wire burn-off rates at a given amperage for a given wire size. But, as burn-off rate increases, penetration decreases. However, Submerged Arc and Spray MIG are deeply penetrating processes at conventional extensions. Controlled increases in EE to moderate levels can maintain satisfactory penetration while enjoying significant increases in burn-off rate. Moreover, many positive side effects (e.g. lower heat input) are generally realized.
As EE is increased, more power is directed to melting wire and less is lost through the base material. Consequently, Heat Affected Zones (HAZ's) are narrower and weld distortion is less. The propensity for burn-thru of thin materials is less (e.g. MIG and TIG roots). In thin material, higher burn-off rates can translate to higher welding speeds.
TipMate™ Nozzles are a simplification of previous commercial hardware for controlling increased Electrode Extension. TipMate™ Nozzles incorporate proprietary ceramic guides that provide positive support and guidance of preheated (softened) wire without suffering failure due to thermal shock. Wire jamming and arc wandering are minimized, if not eliminated.
Unlike twin arc and tandem arc, TipMate™ Nozzles with single wire can be used on every weld: thick or thin - large or small!!!