Fluoride-containing welding auxiliary
Fluoride-containing welding aids react with the metal and form a liquid layer that breaks up oxide layers and improves wetting ability. This leads to a cleaner weld and increases mechanical properties.
Physico-chemical mechanism of action
Fluoride-containing welding aids, such as hydrofluoric acid or potassium fluoride, react with the metal and form a liquid layer on the surface. This layer creates a chemical barrier that breaks up oxide layers and increases the wetting ability of the molten weld metal.
Metallurgical relevance & risks in welding
Using fluoride aids leads to a cleaner weld because oxide layers are avoided. This improves the mechanical properties of the weld and reduces porosity and cracking. However, overdosing can be dangerous: too much fluoride can lead to excessive strength, which impairs the formability of the metal and leads to hot cracking.
Workshop practice & instructions
Use fluoride aids in the recommended concentration. Make sure the metal is clean and free of oxide layers. Wetting should be done at least 5 minutes before welding. Check the mechanical properties of the weld after the process.