Oxygen-Affinic Deoxidizer
Oxygen-affine deoxidizers are additives such as silicon, manganese, or titanium that bind oxygen from the melt and precipitate as oxide slag. This prevents porosity and increases strength.
Physical-Chemical Mechanism of Action
Oxygen-affine deoxidizers react chemically with dissolved oxygen in the melt and form a more stable compound that separates out as oxide slag. This prevents free oxygen from bonding at the growth tips of the metal and promoting pore formation.
Metallurgical Relevance & Welding Risks
A too high content of oxygen-affine deoxidizers can lead to weldability issues, as they change the fluidity of the melt and can affect welding behavior. Additionally, insufficient use can mean that pore formation is not adequately suppressed.
Workshop Practice & Action Guidelines
Use oxygen-affine deoxidizers at the recommended concentration for the respective alloy. Monitor the melting processes carefully and adjust the use to achieve an optimal pore-free weld. A typical use of silicon is about 0.1 to 0.3 % in the alloy.