Wormhole Porosity
A tubular, elongated cavity in the weld metal caused by the directed escape of gas bubbles during rapid solidification. This irregularity significantly impairs the tightness and mechanical load-bearing capacity of the weld seam.
Wormholes are elongated, tube-shaped cavities in the weld metal caused by trapped gases. The bubbles don't have enough time to escape upward during solidification and get stuck in the weld. This makes the weld leak-tight and weakens it mechanically, especially under tensile or compressive loads. In critical cases, it can lead to fracture. To avoid this, make sure the weld pool is clean and dry – no rust, oil, or moisture residues. Also, choose the heat input so that the pool doesn't solidify too quickly and gases can escape.