轻烧镁球中为什么要控制硅的含量 Why control the content of silicon in light-burned magnesium balls

 轻烧镁球中二氧化硅含量要控制在一定的百分比，如果硅含量超标，将显著降低钢的塑性和韧性。硅能降低钢的密度、热导率和电导率。能促使铁素体晶粒粗化，降低矫顽力。硅能促使铸钢中的柱状晶成长，降低塑性。硅能降低钢的焊接性能。因为与氧的结合能力硅比铁强，在焊接时容易生成低熔点的硅酸盐，增加熔渣和融化金属的流动性，引起喷溅现象，影响焊接质量。所以轻烧镁球中一定要严格控制硅的含量，避免炼钢时作为原料带入。

The content of silicon dioxide in light-burned magnesium balls should be controlled to a certain percentage. If the silicon content exceeds the standard, the plasticity and toughness of steel will be significantly reduced. Silicon can reduce the density, thermal conductivity, and electrical conductivity of steel. Can promote the coarsening of ferrite grains and reduce the coercive force. Silicon can promote columnar crystal growth in cast steel and reduce plasticity. Silicon can reduce the welding performance of steel. Because silicon is stronger than iron in binding ability with oxygen, it is easy to generate low melting point silicate during welding, which increases the fluidity of molten slag and molten metal, causing spatter and affecting welding quality. Therefore, the content of silicon must be strictly controlled in light-burned magnesium balls to avoid being brought in as raw materials during steelmaking.