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ESAB'S ELF-SHIELDED CORED WELDING WIRE SAVES TIME IN QUAY CONSTRUCTION PROJECT
ESAB’s Coreshield 8 self-shielded cored wire proved to be crucial to Prien meeting the tight construction schedules. The extension to the Predöhl quay required the construction of a new quay in the harbour basin directly in front of the old quayside. Welding was completed in just six weeks and required 408 type S 355 J2G3 steel plates, with a wall thickness of 25mm, to be attached to the framework of the quay in order to secure the hinged anchors. The hinged anchor piles provide structural reinforcement for the quayside. A total weld length of approximately 730m was required to join the plates to the framework using a=6 fillet welds in the PB, PF, and PD positions, with the steel preheated to 120 degrees C. Random ultrasonic tests were performed on the joints as part of the strict quality assurance regime. Traditionally, manual stick electrode welding would have been used for such welding work, as more productive MAG welding is ruled out due to wind, the requirement to weld directly at the water level, and space restrictions that do not permit the use of a welding tent to provide wind protection. However, the use of self-shielded wires can overcome these problems. Prien showed great interest in a proposal from ESAB Solingen, Germany, to carry out the project with self-shielded cored wire. A presentation on the application of ESAB's Coreshield 8 convinced the construction company of the versatility and productivity advantages of the process. Without delay, the welding qualification procedure to EN 288-3 was successfully passed at SLV Nord so that the work could commence as soon as possible. Coreshield 8 is a self-shielded cored wire benefiting from a fast-freezing slag that supports the weld metal during welding, giving the wire its all-position capabilities. It is particularly suitable for outdoor welding in structural fabrication and other heavy-duty applications where good weld toughness is required - typically 43J is achieved in a Charpy-V test at -40 degrees C. Coreshield 8, 1.6mm wire is generally used with a welding current of 155-240A at 21-25V. Together with the Coreshield 8 wire, Prien used ESAB process package number 114, which consists of the special MT 300 GL torch and the AristoMig 400digital inverter power source. Because of the all-position suitability of Coreshield 8 -1.6mm, the attachment of the plates to the framework was significantly simplified. At a fixed welding current of 200-220A in all positions, a deposition rate of 3kg/h (at 100 per cent duty cycle) was obtained, thereby reducing the welding time substantially compared with MMA. Indeed, such was the success of the project that Prien now plans to include Coreshield 8 in its selection of preferred welding consumables for future contracts.
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