Properties and uses of Ferrosilicon
2019-05-31
Ferrosilicon is a widely used ferroalloy variety.
It is silicon and iron in a certain proportion of
ferrosilicon alloy, is an indispensable material for steelmaking.
Ferrosilicon is the deoxygenation agent of steelmaking, is the alloy agent of silicon Steel, smelting spring steel, heat-resistant steels, but also to add a certain number of ferrosilicon as alloying agent. Production practice has proved that the oxygen in steel can significantly worsen the properties of steel and reduce the mechanical properties of steel. Therefore, deoxygenation must be necessary in the steelmaking process. Oxygen is present in steel in the ﹙FeO﹚ state of ferrous oxide. Silicon is an element with a strong ability to bind to oxygen.
When Ferrosilicon is added to the steelmaking process, the following deoxygenation reaction occurs:
2FeO+Si=2Fe+SiO2
Silica ﹙SiO2﹚ is a product of deoxygenation, it is lighter than steel, floating steel liquid surface into the slag, thus taking off the oxygen in the steel to improve the quality of steel. Silicon and oxygen bonding force is very strong, so smelting some varieties of ferroalloy, but also useful ferrosilicon as reducing agent, such as tungsten iron, aluminum iron and so on.
In the case of tungsten smelting iron, the reaction between tungsten trioxide and silicon
in ferrosilicon in tungsten ore is as follows:
2WO3+3Si=2W+3SiO2 Silicon also has the important physical properties of low conductivity, poor thermal conductivity and strong conductive magnetism. Therefore, Ferrosilicon can be used as an alloying agent when silicone steel ﹙ contains about 2~4﹪﹚. Silicon steel sheet is one of the materials of electric power industry, using it as the iron core of transformer and motor, can greatly reduce the hysteresis loss, can meet the technical requirements of transformer and motor operation. For example, the heat of transformers and motors increases 3~6 times when ordinary carbon steel sheets are used as iron cores. This reduces the power factor of the equipment, but also causes the equipment to run overheated phenomenon, so that it can not function properly.
In addition, some pig iron castings can improve their mechanical properties after adding a small amount of ferrosilicon, and when pouring steel, adding ferrosilicon powder to the insulation cap can play the role of a fever agent.
These are not the main uses of Ferrosilicon and are not detailed here. From the above can be seen, in order to ensure the quality of steel, first of all must ensure the quality of ferrosilicon, that is, should stabilize the composition, reduce impurities. When the composition of ferrosilicon is too large, or when the content of slag and impurities is too high, it will reduce the quality of steel, especially the ferrosilicon alloy, its quality should be better.
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