Surfacing / Overlay Welding
Surfacing is the welding of a wear- or corrosion-resistant layer onto a component. The base material bears the forces; the overlay protects the surface.
Physico-Chemical Mechanism of Action
In surfacing welding, a different, usually harder or more corrosion-resistant alloy is welded onto the surface of a component. The filler material bonds metallically with the base material and forms the protective layer. Common processes are MIG, TIG, electrode, or plasma powder.
Metallurgical Relevance & Risks in Welding
Dilution is critical: too much base material dilutes the deposit and weakens its protective effect. Hardfacing deposits are prone to cracking and require preheating and slow cooling. The layer thickness must match the service conditions.
Workshop Practice & Instructions
Keep dilution low, choose the cladding material to match the load, and follow the manufacturer's heat input guidelines. After welding, inspect the layer for cracks and check the required hardness.