Külmliide

Külmliide is an Estonian term that translates to "cold joint" or "cold weld." It refers to a type of defect that can occur in metal casting or welding processes. A külmliide happens when molten metal fails to properly fuse with an existing surface or another stream of molten metal due to insufficient temperature or flow. This results in a weak, incomplete bond where two pieces of metal meet, often appearing as a distinct line or a porous area.

In casting, külmliide can occur if the molten metal cools too much before it completely fills a mold cavity or if two separate streams of metal meet without adequate heat to merge. This can lead to casting defects that compromise the structural integrity of the final product. Similarly, in welding, a külmliide can form if the welding heat is too low, the travel speed is too fast, or if there is contamination on the base metal, preventing proper fusion between the filler material and the workpiece.

The presence of a külmliide can significantly weaken a component, making it prone to failure under stress or load. Identifying and preventing külmliide is crucial in manufacturing to ensure the quality and reliability of metal parts. Techniques to avoid this defect include proper temperature control, ensuring adequate melt flow, maintaining clean surfaces, and using appropriate welding parameters.