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Oxygen Activity in the Melt

Oxygen activity in the melt measures the chemical potential of free oxygen molecules. It influences reactions and the metal's microstructure.

Physico-chemical Mechanism of Action

The oxygen activity in the melt indicates how strongly oxygen molecules move in the liquid melt. It is a measure of the concentration and chemical potential of free oxygen.

Metallurgical Relevance & Welding Risks

High oxygen activity can cause rapid oxidation, leading to porosity and loss of strength. At low activity, the microstructure can form unevenly, resulting in toughness problems.

Workshop Practice & Instructions

To control oxygen activity, silicon or other deoxidizers are often added to the melt. For high-carbon steels, careful control of temperature and cooling procedure is essential.

MetallurgieSchweißtechnik

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