More Efficient Submerged Arc Welding

The versatile, user-friendly Versotrac EWT 1000 tractor from ESAB Welding & Cutting Products (Denton, TX) is ideal for submerged arc welding, MIG/MAG and carbon arc gouging. Its rugged, modularized components can be disassembled into smaller units, hand-carried into confined or remote spaces and then reassembled in minutes. No tools are required. “This modular tractor system recognizes the portability needs of ship, barge, offshore, wind tower and structural steel applications. Versotrac is a truly modular welding tractor, allowing you to take it anywhere without the need for cranes or other lifting devices,” said Magnus Svedlund, the global product manager of SAW Equipment at ESAB. The Versotrac can be rebuilt for optimum beam welding positions (including fillet welds in the flat position), comes in four- and three-wheel versions and can be connected together with any of the current ESAB submerged arc power sources, as well as previous generations of ESAB power sources and many other brands of analog-controlled power sources already in the market.

A new wire spool handling system detaches for easier transportation and more ergonomic loading of wire spools, while steering handles let operators easily change weld point position. The modular design of the Versotrac has been enhanced with the EWH 1000 welding head and EAC 10 controller, both of which detach. Their associated quick connectors and automatic detection/setup by the controller let users switch between the SAW, GMAW and gouging processes in seconds. The EWH 1000 welding head incorporates a robust wire feed system that can weld with single wires up to 5 mm and up to 1000A @ 100 percent duty cycle. To maximize productivity, the EWH 1000 can be used with a twin-wire process. A closed-loop encoder control system ensures precise wire feed speed control. “In keeping with our quick setup philosophy, we designed this welding head for tool-less interaction on all major adjustments and incorporate scales,” noted Svedlund. “Memory functions on the wire feed pressure and wire straightener further simplify and reduce down time.”

The Versotrac uses the entirely new and intuitive EAC 10 controller for greater ease-of-use. Its simplified interface includes functions users need for tractor-based and other light-automation applications, making more room on the display for important functions like real-time, on-screen heat input to monitor and control weld quality at all times. The EAC 10 pendant detaches from the base control unit so operators can work in a comfortable position and change settings from a distance. The controller works with all current ESAB submerged arc welding power sources, as well as most analog power sources on the market.

ESAB also offers PIPEWELD 78LH, a low hydrogen flux for longitudinal or spiral welding of pipeline steel grades, such as X70 and X80, using multi-wire submerged arc welding processes. A new flux formulation and production process enable PIPEWELD 78LH flux to meet the H4 classification of ≤ 4ml of diffusible hydrogen per 100g of weld metal as produced. Because of its low hydrogen formulation and its moisture resistance, PIPEWELD 78LH enables coating within a few hours after welding, improving throughput. The higher moisture pickup of other fluxes may cause out-gassing issues when flux is left in the hopper for a long time and then pipe may need to sit for several days after welding to prevent “jeeping” (blistering). “We tested PIPEWELD 78LH versus competitive fluxes and the previous version of OK Flux 10.77 and proved that it reduces moisture pick-up and diffusible hydrogen levels,” stated Halinson Campos, the product business manager for filler metals at ESAB.

ESAB guarantees the H4 classification when users receive the flux in a BigBag package, a 2,000 lb to 2,200 lb bulk package made from a woven polypropylene material with a multi-layered aluminum lining that keeps moisture away during storage. PIPEWELD 78LH is also available in a 50 lb Flux Pack™ that uses a thick LDPE material. This flux controls the bead width and profile to deliver proper and adequate reinforcement. “A low transition angle between the weld crown and base plate prevents over-welding and the associated waste of filler metal, as well as cost saving in the later pipe coating operation, since the coating thickness can be reduced,” added Campos. “PIPEWELD 78LH also provides a smooth surface finish, even at high welding speeds. Because of its improved grain size, it can be recaptured and reused, prolonging the interval between flux hopper refills.

This flux is specifically designed for multi-wire submerged arc welding processes, such as twin-wire, tandem or the patented Integrated Cold Electrode (ICE™). By feeding an electrically cold electrode into the weld puddle, ICE increases deposition rate without increasing heat input to help preserve mechanical and metallurgical properties.

ESAB Welding & Cutting Products, 2800 Airport Road, Denton, TX 76207, 800-372-2123, www.esabna.com.