Hyundai Welding Products  

Electrodeposited-coating (E-coating) is a well-established technique in the automotive industry to protect car parts against corrosion, but its application on welded components can be problematic due to poor adherence onto silicate islands left behind on welds by the GMAW process. Lacking solid E-coating protection, these spots may later act as initiators of rust development when vehicles are exposed to corrosive environments such as humidity, temperature changes, sea winds and de-icing salts. Removal of the silicates is an effective measure, but is costly in highly efficient fabrication lines and therefore undesired. To overcome this problem HYUNDAI WELDING developed the world’s first E-coating friendly welding wire, the SM-70MT. This unique product features ultra-low silicates formation and allows car parts to be E-coated without post-weld cleaning of the weld surface, as illustrated by the photos. It also delivers virtually spatter-free welding along with excellent gap bridging.

SM-70G is developed for use with 100% CO2 shielding gas or with Ar/10-30% CO2 mixed gas. When used with pure CO2, fabricators benefit from the deep and round weld penetration which is characteristic for this gas. It gives optimal protection against cold laps and lack of root penetration. Both defects are notorious initiators for fatigue cracks in heavy equipment components which are subjected to dynamic loading, such as booms and arms. Used with mixed shielding gas with a high fraction of CO2, weld penetration is less profound, but still acceptable. SM-70G offers productivity across all Heavy Equipment applications industrial segments such as frame and boom welding which allows companies to adapt to needs of the market environments. Recording of welding parameters reveals extremely stable arc behaviour of SM-70G from the E-Line range, whereas the conventional solid wire shows an erratic arc behaviour with occasional arc extinction.

Semi metal-cored wire specifically designed for single and double-sided tandem welding of longitudinal stiffeners (T-fillets) on gantry panel lines, using tandem-twin welding heads. It shows the excellent welding characteristics of a rutile flux-cored wire, but combines this with a very low slag production and is therefore labelled “semi metal-cored”. At around 90%, the weld metal recovery is higher than with standard rutile flux-cored wires. It is welded in 100% CO2 shielding gas giving the deep and round weld penetration which is favourable for obtaining fillet welds free of fusion defects. The remaining minimal slag is easily removed from an extremely smooth weld surface. Mechanical properties of the weld are excellent. The diffusible hydrogen content of the weld metal is below 5ml/100g. Supercored 70MXH can be used on zinc-primed or rusty plate, reducing the risk of porosity. Welding speed up to 100 cpm can be reached for an a=6 size fillet weld.

With modern filler metal formulations, the process has grown mature and many fabricators in the structural segment are adopting it to increase their welding economy and thereby their competitive edge. Just like stick electrodes, self-shielded cored wires produce their own dependable gas shielding and there is no need to place any wind screens or tents. Supershield 11 is classified E71T-11 according AWS A5.20. It is a versatile, all-round cored wire intended for single and multi-pass welding of lighter constructions with no CVN weld metal toughness requirements. It is welder-friendly, with a smooth and stable arc and low-spatter. The slag is fully covering the weld surface and easily released. It is welded on DC- polarity, but its use is easy to learn for welders familiar with DC+ welding with gas-shielded cored wires. It is also available on smaller spools with 5 or even 1kg of wire to facilitate use with small portable (yard) feeders.