African Fusion talks to ESAB South Africa’s product manager for filler metals, Kevin Xaba, about the premium gas-shielded, low-silica metal-cored wire, Coreweld 46 LS, a high-deposition, low-heat-input welding consumable designed to deposit exceptionally low amounts of silica on the weld surface.
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A component fabricator supplying a mobile equipment OEM increased productivity by 17% by switching from a conventional metal-cored welding consumable to ESAB’s Coreweld 46 LS.
ESAB Coreweld metal-cored wires have been developed to meet the needs of demanding welding applications for structural steel, heavy equipment, pressure vessels, petrochemical plants, offshore rigs, railway vehicles, ships and general fabrication. “ESAB pioneered the development of gas-shielded flux-cored welding (FCAW) nearly 60 years ago, so we can now offer the broadest variety of carefully crafted mild steel and low alloy flux- and metal-cored wires,” says Kevin Xaba, ESAB South Africa’s product manager for filler materials.
“Fabricators have a wide range of welding processes and consumables to choose from, each with their own advantages and disadvantages. Within this mix, metal-cored wires are becoming increasingly popular because they offer higher deposition rates and faster travel speeds, and improved cost-effectiveness,” he continues.
Metal-cored welding wire comprises tubular wire filled with metal powders, alloying elements and arc stabilisers. “Our Coreweld metal-cored wires combine high deposition rates and efficiencies, high travel speeds, excellent penetration and ease of use. They also provide excellent arc stability and outstanding penetration and wetting, with superior root and sidewall fusion,” Xaba notes.
ESAB Coreweld 46 LS
Coreweld 46 LS is a high productivity wire capable of welding at high deposition rates with relatively low heat input compared to solid wires. This is due to a higher current density. “Coreweld 46 LS is a fantastic metal-cored wire for fabricating and/or repairing yellow-metal equipment such as the dump truck and excavator buckets used in South Africa’s mining and construction sectors,” notes Xaba.
Most notably, he says the Coreweld 46 LS is formulated to remove silica deposits from the weld metal, producing an exceptionally clean weld surface free of silicon islands.
Designed for welding both thin and thick steel plates with Ar+CO2 shielding gas mixtures, Coreweld 46 LS produces a wider arc than conventional solid wires, allowing larger gaps to be accommodated. The wire classification is SFA/AWS A5.18: E70C‑6M H4; EN ISO 17632-A: T 46 4 M M20 2 H5 and has approvals from all the following: BV: 4Y40 H5 (M20 and M21); DB: 42.039.38; VdTÜV: 12152; ABS: 4Y400M H5; BV: 4Y40 H5; CE: EN 13479; DNV: IV Y40MS(H5) (M20 & M21); and UKCA: EN 13479.
Delivering yield strength of 485 MPa, tensile strength of 545 MPa, 29% elongation, Charpy impact values of 72 J at -40 °C, and diffusible hydrogen levels of less than 4.0 ml/100 g, this wire is ideal for welding C-Mn steels, including those susceptible to hydrogen-induced cracking. “Deposition rates are a particular advantage, with the 1.2 mm wire diameter offering 1.3-8.0 kg/h, depending on amperage and voltage settings,” Xaba adds.
A yellow-metal success story
In a case study for a component fabricator supplying a mobile equipment OEM, the fabricator increased productivity by 17% by switching from a conventional metal-cored welding consumable to ESAB’s Coreweld 46 LS.
“The fabricator was producing hydraulic links for mobile vehicles using two robot-based welding systems and a competitor’s metal-cored wire. Production capacity was limited by the accumulation of silicon islands during multi-pass welds. This forced the operator to stop each robot for five minutes to remove the silicon islands from the welds of every component before restarting the welding cycle.
“The switch to using a 1.2 mm Coreweld 46 LS eliminated the need for inter-pass grinding, enabling the robots to complete each component without interrupting the cycle. In addition, the welding capacity at both welding stations increased by 17%. Combined, the switch resulted in total production cost savings of 13% and an annual cost savings of €60 000,” Xaba explains.
“While very low levels of silica on the weld surface were key to this success, delivering savings on downtime per cycle for each robot station, Coreweld 46 LS also offers other production advantages: a high deposition rate with relatively low heat input compared to solid wires, for example, and if used manually, these wires are easier to use than solid wires and offer far better productivity for those still using stick electrodes,” he adds.
Remanufacturing mine drill bits
Citing a second Coreweld 46 LS success story, Kevin Xaba says the wire is also ideal for weld repair and build-up applications.
In a welding remanufacturing department, two welding robots were being used with solid wire to build up the profiles of worn drill bits before hard-facing. Several problems were encountered: the 1.2 mm solid wire required a relatively low deposition rate to minimise heat input; excessive spatter caused downtime for cleaning the welding torches; and costly grinding operations were necessary to remove spatter from each component. This was causing capacity shortages and production bottlenecks.
Test welding was performed using the ESAB 1.4 mm Coreweld 46 LS wire, yielding very good results: essentially no spatter and a significantly higher deposition rate. The company therefore decided to switch from the previously used 1.2 mm solid wire to a 1.4 mm Coreweld 46 LS wire. This increased production capacity by 42% at the two robot stations. It also resulted in less downtime due to lower torch-cleaning requirements and less time spent cleaning spatter from drill bits after welding.
The total production cost for this part of the remanufacturing operations was reduced by 17%, resulting in annual cost savings of €100 000 from these two robot stations.
“In this case study, the higher deposition rate associated with Coreweld 46 LS was the critical factor, and because of the higher current density associated with metal-cored wires, the heat input could be kept low at the higher deposition,” Xaba explains, adding that lower silicon levels compared to using solid GMAW wires are also an advantage in this type of application.
“As a world leader in Welding, cutting equipment and consumables, we at ESAB can offer complete fabrication solutions for virtually every application, along with the support needed to ensure that products such as our Coreweld 46 LS deliver the results that South African fabricators need,” concludes Kevin Xaba.
