Oxygen Segregation Zone
The oxygen segregation zone is a local enrichment of oxygen and oxide inclusions inside the ingot during solidification, degrading mechanical properties. It results from incomplete deoxidation and density differences in the melt.
Physicochemical Mechanism of Action
The oxygen segregation zone forms when steel materials are incompletely deoxidized during cooling. This leads to local enrichments of oxygen and oxide inclusions in the interior of the ingot. Density differences between the rich and poor areas cause mechanical stresses that damage the microstructure.
Metallurgical Relevance & Risks in Welding
The oxygen segregation zone can lead to local deformations and cracks. It lowers the toughness and strength of the steel and increases susceptibility to hot cracking. These hazards are particularly critical in highly stressed components.
Workshop Practice & Action Instructions
To avoid the oxygen segregation zone, careful deoxidation is essential. Use high-quality shielding gases and apply a controlled cooling process. For heavily loaded parts, pay attention to homogeneous solidification and avoid rapid cooling rates.