引言铸态球墨铸铁的硬度可以通过改变组织中的珠光体量和铁素体量进行控制。减少铁素体与珠光体的比例,一般将使硬度提高。所形成的铁素体量还可以受调整成份或改变冷却速度的影响。由于球墨铸铁一般的含硅量大于2.2％,而硅起着墨化剂的作用,促进了铁素体的生成,所以铁素体与珠光体比例的控制,一般借助于加入促进形成珠光体的元素来实现。这些元素 Introduction The hardness of cast nodular cast iron can be controlled by changing the amount of pearlite and ferrite in the structure. Reducing the ratio of ferrite to pearlite generally increases the hardness. The amount of ferrite formed can also be influenced by the composition or the cooling rate. Since ductile iron generally contains more than 2.2% silicon, and silicon functions as an etchant to promote the formation of ferrite, the ratio of ferrite to pearlite is generally controlled by the addition of an element that promotes pearlite formation to fulfill. These elements