An exclusive WESPEC extrusion process has been developed to produce two separate flux coatings around electrode wires. “During manufacturing the two coatings are applied simultaneously in a single extrusion operation. Each coating has different but complementary chemical compositions, which together result in much better arc stability and weld quality..
single electrode coatings have to contain both electrical conducting elements necessary to establish an ionising path for a stable arc, and those for the protective gaseous atmosphere to prevent oxygen, hydrogen, and nitrogen pick-up by the molten metal.
In addition, the coating provides the ingredients to form the protective slag over the hot metal and various flux constituents that help to remove oxides and other impurities from the molten metal.
With double-coated electrodes, the constituents required in an electrode coating are split between the two layers. The inner layer contains the ionising and conducting ingredients. This enables a strong and stable arc to be concentrated around the wire.
The second coating, however, which contains the shielding and slag-forming elements, is non-conductive, that helps to concentrate the electrical arc to the inner core of the electrode, resulting in a rigid arc that is easier to direct into the root of a welding groove, he explains, adding that single electrode coatings are usually more insulating, which are, therefore, more difficult to direct into narrow gaps.
The inside coating enables a deep crater while welding, which gives excellent stiffness and positional control as well as deeper penetration.
Advantages of the double-coated electrode solution include:
- A very stable arc that is insensitive to the effects of arc blow.
- Sustained high-quality fusion at very low weld-current settings.
- Excellent usability for the operator.
- Exceptional wetting even at low current.
- High tolerance for irregular gaps.
- Superior metallurgical purity.
- Stable arc with low spatter levels.