Jürgen Tuchtfeld of voestalpine Böhler Welding talks about UTP’s AF ROBOTIC seamless hardfacing wires.
In many heavy industrial segments, such as cement and mining; the iron and steel industry; recycling; power generation; and the oil and gas industry, component wear is an ever-present challenge.
Metal-to-earth and metal-to-metal contact leads to component wear by abrasion, impact, heat or a combination of these factors and, eventually, to the reduction of the efficiency of production equipment. In the end, components must be repaired or even replaced. As a consequence, business owners face production-stealing downtime and additional resources such as maintenance teams are required to address the wear damage. In this context, it is extremely important for maintenance managers to rely on repair and maintenance routines.
Based on experience of its customers’ needs, voestalpine Böhler Welding has developed a family of iron-based, seamless, gas-shielded-cored wires, which delivers superior wear resistance with all-position application capabilities. Because of its excellent weldability in manual as well as in mechanised applications, this new series of wires has the name ‘ROBOTIC’ incorporated into its designation as a common identifier.
Table 1 gives a short selection of available wires in the ROBOTIC range.
The chemical composition of the wires consists of an iron-based alloy with varying proportions of carbon, silicon, manganese, chromium and molybdenum and, in some cases, other carbide formers (Nb, V, T, B, Ti). This covers a wide range of technically important hard- nesses from 250 HB to 65 HRC.
All of these ROBOTIC wires are seamless cored wires, the manufacturing starting point being a sealed tube, which is then filled with flux by means of a special vibration technique. The tube is then drawn to the desired diameter in a multi-stage process. Finally the wire is chemically copper-coated and spooled onto basket spools or into drums.
Due to this particular manufacturing process, the filler wire has no permeable joints and thus no moisture can di use into the powder filling. Any post-drying treatment is therefore unnecessary.
As soon as welders start to use UTP AF ROBOTIC wires, the large window of suitable welding parameters will impress them. The reason for this is partly due to the excellent feeding properties of the copper-coated wire, but it lies also in the structure of the cored wire itself. Since only the metallic tube of the cored wire can conduct the current, a very high current density in the cross section of the wire is produced. Thus, an extremely stable arc can be achieved with spatter-free droplet transfer, even at low current settings.
If we compare the acceptable welding parameter windows of solid wires with those of the ROBOTIC wires, the result is an impressive advantage in favour of the cored wires. For example, for a 1.2 mm cored wire, a useful welding range be- tween 120 to 280 A and 20 to 34 V can be found, while for a solid wire with the same diameter, the range is limited to 220 to 280 A and 28 to 34 V.
As a result, ROBOTIC wire deposits on narrow edges as well as high-productivity surfacing jobs can be successfully completed without problems, in the down-hand position as well as in position. And due to … read more…