Flux-cored welding wire has been widely used in my country’s metallurgical engineering construction, shipbuilding industry, machinery manufacturing industry, energy and chemical construction. The large-scale self-protected flux cored wire semi-automatic welding has been adopted in oil pipeline reconstruction project, petroleum pipeline project and Sudan pipeline project, which has accumulated valuable experience for the use of flux cored wire for oil and gas pipeline welding.
The flux cored wire is suitable for welding in various spatial positions, and its continuity is also conducive to automated production, so the industrial production field has been rapidly developed. The appearance of flux cored wire is like ordinary welding wire. The flux core inside also contains arc stabilizer, deoxidizer, slag-forming agent and ferroalloy, etc. It has a similar role as electrode coating and can protect molten droplets and molten pool from oxidizing and nitriding. A series of beneficial effects such as auxiliary welding seam formation, stable arc, deoxidation and desulfurization and infiltration of alloy elements.
Flux cored welding wire has the following characteristics:
(1) The welding speed is fast, the production efficiency is high, and continuous automated and semi-automated production can be carried out.
(2) The welding quality is good and the welding seam is beautifully formed. Because the composition of the drug core changes the physical and chemical properties of the pure CO2 arc atmosphere, the splash is small and the splash particles are fine, which is easy to remove. Similar to hand arc welding.
(3) Low comprehensive production cost. The total cost of welding production is composed of welding materials, auxiliary materials, artificial power consumption and other expenses. The flux cored wire has a high effective utilization rate, the welding current density is greater than that of hand arc welding (up to 100A/mm2), the welding wire melts quickly, and the productivity is 3 to 5 times that of hand arc welding. Due to the large penetration depth, the welding groove can be smaller than in manual arc welding, and the height of the blunt edge can be increased, which not only saves the amount of filler metal used during welding, but also increases the welding speed. Therefore, the overall production cost of flux-cored welding wire is only half of that of manual arc welding.