Need More Speed: A Case for the Welding Carriage
Aumayr is one of Austria’s most renowned manufacturers of ventilation pipe systems and has approximately 300 employees working at three locations in Austria and the Czech Republic. The family-run company, founded in Linz in 1965, has a top-class pool of equipment for metalworking, featuring computer-controlled laser cutting and stamping machines, servo-electric bending machines, and other high-tech systems. Its equipment, together with its in-house design and development department, enable the company to develop and produce custom-made products from scratch.
This innovative metalworking approach means that Aumayr can manufacture ventilation pipes that conventional ventilation manufacturers would struggle to produce. At the start of 2018, the company received a large order for welded stainless-steel ventilation pipes. Even as the order was being calculated, it became clear that new alternatives to the previously manual welding process would be required due to the hundreds of running meters of weld seam and the customer’s stringent quality demands. Above all, sheet metal thicknesses up to four millimeters had to be welded without warping and in consistently high quality to create ventilation pipe components that were sometimes as long as 19.6 feet, as high as 8.2 feet, and as wide as 4.9 feet.
Mechanization, Quality, and Cost EffectivenessThe key aims when the ventilation components were being manufactured were to have a mechanized welding process, achieve perfect weld-seam quality in all components, and optimize costs by eliminating the need for reworking and working at a higher welding speed.
To meet these criteria, Aumayr decided to purchase a Fronius welding carriage: the sturdy, flexible ArcRover 22. “The compact design of the welding carriage and its compatibility with the Fronius TPS 5000 CMT and TPS/i 500 welding systems we already had in our fleet were the primary reasons for choosing it. We’ve now been using the ArcRover 22 since March 2018. Our welders particularly like the durability and ease of use of the welding carriage,” explains Erwin Kunst, Head of Metalworking at Aumayr. He continues, “Even during the initial tests, we were able to achieve improved and, most importantly, consistent weld-seam quality at a higher welding speed. The carriage is also easy to mount and always stays on the track thanks to its guide rails.”
Achieving Perfection by Mixing ProcessesThe welding experts opted for a pulse process with an average amperage of 300 amperes in order to achieve optimal root formation when welding the approximately four-millimeter thick side walls of the ventilation components. This approach ensures the necessary heat input. The somewhat “cooler” Fronius CMT (Cold Metal Transfer) mixed process—unbeatable in terms of welding quality—was used for section welding the flange plates and bracing ribs in longitudinal and transverse directions. The mixed process adjusts the ratio of hot pulse process cycles to cool CMT process phases as required for the specific application, resulting in perfectly welded, virtually spatter-free metal connections with zero distortion.
“The constant speed of the welding carriage combined with the right welding processes were the key factors in achieving the consistently reproducible high quality of the weld seams,” explains Erwin Kunst. “It ultimately vastly exceeded our expectations. The Fronius welding experts deserve a special thank you for their advice and support right from the start. Together we were able to significantly optimize the welding quality as well as the production times. Investing in the ArcRover 22 was absolutely the right decision.”