The production of flux-cored welding wire is a precise process integrating materials science, metallurgy, and machining. The core lies in uniformly coating a specific formula of flux powder into a steel strip and processing it into the final product.
1. Raw Material Preparation
This process begins with the careful selection of two core raw materials. First, the steel strip, which serves as the outer sheath, must have a material (such as low-carbon steel or stainless steel) and specifications strictly matched to the end use of the welding wire. The other is the soul that determines the performance of the welding wire-the flux powder, which is formulated from various mineral raw materials and ferroalloys in precise proportions.
2. Flux Powder Preparation
The prepared raw materials are fed into a mixing device for thorough stirring to ensure high uniformity of composition. Subsequently, the mixed flux powder usually undergoes drying to remove moisture, ensuring smooth subsequent production and stable product performance.
3. Forming: The steel strip is first rolled into a U-shaped groove by a rolling mill. During continuous travel, a specialized filling device precisely and evenly fills the U-shaped groove with flux powder. Then, rollers close the two sides of the steel strip, firmly encapsulating the flux powder, forming the initial shape of the flux-cored welding wire.
4. Drawing: The preliminarily formed welding wire undergoes a series of drawing dies for multiple drawing passes. This process gradually reduces the wire diameter while significantly improving its density and surface quality. The drawing amount at each step must be precisely controlled.
5. Heat Treatment (Optional): Depending on product performance requirements, the drawn welding wire sometimes requires heat treatment such as annealing to improve its internal structure, toughness, and welding process performance.
6. Surface Treatment
To prevent rust and enhance conductivity during welding, finished welding wires typically undergo surface treatments such as copper plating.
7. Winding and Packaging
Finally, the welding wire is wound onto a special spool for easy transport and use, and then packaged before leaving the factory.
