← Glossary

Oxygen Activity Threshold

The critical limit of dissolved oxygen in the melt above which undesirable oxides remain as macroscopic inclusions within the microstructure.

If too much oxygen gets into the weld pool, oxides form that no longer float out cleanly and remain as inclusions in the seam. That makes the structure porous and the weld brittle and crack-prone. So you have to shield the pool well so no oxygen gets to it. With deoxidizers in the filler material or shielding gas, you keep the melt clean and avoid pore formation.

MetallurgieSchweißtechnik

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