Pulsed and spray arcs in one characteristic

The impressive alternative for efficient steel welding

Steel and mechanical engineers are getting ever more insistent in their calls for greater efficiency when welding steel. This means efficiency in terms of seam welding as well as quality and overall cost. Fronius has responded to these demands with the new, yet already proven, "PCS" (Pulse-Controlled Spray Arc) characteristic. The first users of the system from the leader in arc welding technology were extremely enthusiastic: "This new characteristic allows us to reduce the time spent on some components by up to 35 percent", explains welding engineer Reinhard Kellner, responsible for welding technology and quality control at Laempe & Mössner in Barleben, Germany. As a global technological leader, welding is an important core competence at Laempe & Mössner, manufacturers of high-quality machinery and systems for the foundry industry.

Efficient manufacturing processes are critical for competitive production in high-wage economies. Fronius provides this efficiency in welding using innovative technologies and processes that result in high levels of productivity. The user can choose the most suitable option from a range of more than 1,300 digitised characteristics at their disposal. New to the scene are the PCS characteristics that promise considerable gains in quality when welding steel parts between 1 and 20 mm thick. These characteristics ensure that the welding process can be easily controlled while simultaneously providing a higher rate of deposition, deep and effective fusion penetration, less heat input and minimal spatter. Welding times are shortened, in some cases less weld layers are required, and the cost of reworking is hugely reduced; these are all significant steps in the right direction. Spatter, extra surface finishing and straightening are largely things of the past. 

From a technical viewpoint, the Austrian welding experts have succeeded in directly combining the low-spatter pulsed arc with the spray arc - and with no intermediate arc. Where necessary the welding process starts with reduced power in the pulsed range. Depending on the sheet thickness, the operating point either remains in this area or is followed by an aggressive spray arc. Short-circuit-free welding is guaranteed for the entire wire feed speed range from 1.5 to 22 m/min. The base characteristic is defined for gas mixtures of 8% CO2 + 92% Ar and filler metals of G3Si1 (international: ER70) with a wire diameter of either 1.0 or 1.2 mm. Variants for other gas mixtures, filler metals and wire diameters are also available. A large window in both the positive and negative range is provided by the "ideal value" of 30 V working voltage for the purposes of correcting the arc length. Straight to the welding point - with the new PCS characteristic, Fronius has developed a standard process that ensures reliable, reproducible, economic and high-quality welding results with as little rework as possible. The large amount of variability allows a range of applications far higher than from conventional characteristics.