When using the railRunner mechanised solutions with a flux-cored wire, the time to completion is only 49 min, compared to 468 min with SMAW, which is nearly 10 times faster. consumable material usage is 2.6 kg, more than 20% less. Table 2 provides details of the assump- tions and calculations for SMAW, semi- automatic FCAW, and mechanised FCAW using railRunner. Conclusions Whilst selecting the correct equipment in combination with the correct welding consumables is essential to achieve these concrete benefits, synergic lines built into the welding equipment, tailored for use with the specific welding consumable products, in addition to the expertise of- fered by the welding solutions provider to overcome challenging welding applications
The main difference between industrial robots and collaborative robots lies in how they interact with operators in the work area.
butt welds in the vertical-up or frontal posi- tions were usually completed using SMAW. Manual welding for these applications is associated with clear limitations, however, due to the following issues: • Frequent interruptions to exchange the stick electrodes and for slag removal. • Material waste and the associated high cost of welding consumables. • Skilled manual welders are necessary. • Repeatability and meeting the require- ments of established WPSs are seldom ensured. To overcome these issues, GMAW and FCAW semi-automatic solutions have been adopted over the past few years, resulting in significant improvements across all the limitations mentioned above. Flux-cored wires featuring a fast–freez- ing slag system to support the weld pool proved to be the most reliable and efficient welding consumables for positional welds on LNG tanks. The deployment of semi-rigid and flexible track-type mechanised welding carriages, in combination with flux-cored wires, resulted in a further enhancement, resulting in the benefits below: • Higher production efficiency. • Deposition rates as high as 85-90%: 5-8 times higher than that of SMAW. • No electrode wastage. • Higher weld quality. • Greatly reduced numbers of stops and starts. • Minimised critical weld failures and rework. • Eliminated almost all weld grinding and cut-outs. • Less welding skill is required. • Mechanised equipment maintains pre-
cise control of the welding parameters. Modelling time and material efficiency for a typical butt weld of a 9% Ni steel LNG tank with SMAW, one may realistically achieve a process duty cycle – arc-on time vs total time – of about 20%, with a 1.5 kg/hr de- position rate and material losses of about 30% or more. Based on those assumptions, as shown in Table 1, for a typical case of 25 mm plates with an X weld preparation, calculations for the SMAW process yield a total manufactur- ing time of 468 min and 3.34 kg of welding consumables per 1 m of welding. In the case of the Böhler Welding mechanised solution, the process duty cycle can reach up to 80% for longitudinal non-interrupted welds, with a deposition rate of 3.4 kg/hr and a material efficiency above 90%. That leads to a very interesting scenario: the time to completion is only 49 min, compared to 468 min with SMAW, which is nearly 10 times faster. In addition,
Scan or click the QR code to access voestalpine Böhler Welding’s weld- ing automation page. is what ultimately makes the real difference between achieving the ‘Perfect Weld Seam’ or not.
Table 1: A comparison of the process efficiencies of SMAW, semi-automatic FCAW, and mechanised FCAW using Böhler Welding’s railRunner mechanised solution.
Theoretical deposition rate (kg/hr)
Effective deposition rate (kg/hr)
Process
Duty cycle
SMAW
20% 35% 85%
1.5 3.4 3.4
0.3
FCAW: semi-automatic FCAW: Mechanised using railRunner
1.19 2.89
Table 2: The welding times and filler metal consumption calculations for the SMAW, semi- automatic FCAW, and mechanised FCAW comparison.
Process
Welding time (min) Kilograms consumed (kg) Efficiency
SMAW
466 118
3.34 2.60 2.60
70% 90% 90%
FCAW: semi-automatic FCAW: Mechanised using railRunner
49
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March-April 2026
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