Which of the following serves as a good deoxidizer in steel melting?

A good deoxidizer in steel melting is essential for removing oxygen from molten steel, which can lead to defects and affect its properties. Manganese, silicon, and aluminum are all effective deoxidizers used in steelmaking processes.

Manganese serves not only as a deoxidizer but also helps to improve the toughness and hardness of steel. It reacts with oxygen to form manganese oxides, which can be removed easily from the molten metal.

Silicon is another effective deoxidizer. It forms silicon dioxide, which helps remove oxygen from the melt. Additionally, silicon enhances the fluidity of molten metal and contributes to the overall mechanical properties of steel.

Aluminum is widely used as a deoxidizer because it has a strong affinity for oxygen, forming alumina that can easily be separated from steel. The use of aluminum can significantly improve the quality of steel by minimizing the presence of oxygen and associated defects.

Since all three elements—manganese, silicon, and aluminum—are capable of serving as effective deoxidizers in steel melting, the answer indicates that collectively, they all contribute to deoxidation, making “all of these” the most comprehensive and appropriate choice.