This type of welding wire features a unique structure, with an outer layer made of low-carbon steel or low-alloy steel and an inner core filled with a mixture of flux agents, deoxidisers, and alloying elements. During welding, the flux core undergoes chemical reactions under the high temperatures of the arc. On one hand, it generates protective gases (such as carbon monoxide and hydrogen) to form a gas film that isolates the molten pool from atmospheric corrosion. On the other hand, it produces slag that covers the weld surface, preventing oxidation of the high-temperature metal and slowing down the cooling rate to reduce crack formation. This ‘gas-slag combined protection’ ensures weld quality.

It exhibits excellent welding process performance, enabling all-position welding, stable arc, strong penetration, and high tolerance for contaminants such as rust and oil on the base material surface, making it suitable for rough construction environments. The weld metal typically possesses good mechanical properties, with tensile strength and toughness meeting the requirements of most carbon steel and low-alloy steel structures.

In terms of application scenarios, gasless self-shielded flux-cored welding wire is an ideal choice for outdoor and field operations, widely used in construction steel structure installation, bridge construction, pipeline repair, engineering machinery maintenance, mining equipment welding, and other applications, particularly suitable for high-altitude, field, or narrow-space operations where it is difficult to install protective gas pipelines.