How is 'flux' defined in welding?

The term 'flux' in welding is defined as a chemical cleaning agent applied to the surfaces being welded. Its primary role is to facilitate the welding process by preventing oxidation of the metal surfaces and removing impurities that could compromise the quality of the weld joint. Flux helps to ensure a strong bond between the metals being joined by creating a barrier that protects the molten weld pool from atmospheric contamination.

In various welding processes, especially in soldering and brazing, flux can also help in improving the flow of the filler material by lowering the melting point of contaminants. This enables the metals to adhere better, leading to a more effective and durable joint. Therefore, understanding the role of flux in welding is crucial for achieving optimal results in metal fabrication and fitting processes.