w(Si)、w(C)量及冷却速度对铸态球铁组织的影响

Influence of Silicon and Carbon Content and Cooling Rate on Structure of As-Cast Nodular Iron

用热分析法研究了w(Si)、w(C)量和冷却速度对球铁中石墨和基体组织的影响。结果表明:适量增加孕育剂加入量能缩短球铁凝固过程中共晶平台的宽度,有限减少或避免石墨的畸变;在孕育剂加入量为1.38%时,能够得到66.8%的铁素体含量且球化效果良好的球墨铸铁;在w(C)量为3.94%、w(Si)量为2.23%时,由于CE达4.9%,导致与石墨漂浮相关的开花状石墨和枝晶石墨产生。

The influence of w（Si） and w（C） and the cooling rate on the graphite and matrix structure of the as-cast nodular iron was investigated by using thermal analysis.The results showed that properly increasing inoculating Si addition could shorten the eutectic transition duration during the solidification process of the nodular cast iron that in some degree reduced or avoided the graphite degeneration,and when adding 1.38% of inoculant,it＇s possible to obtain the nodular iron with 66.8% ferrite and good nodularity.When w（C） was of 3.94% and w（Si） of 2.23%,the CE reached 4.9% that caused formation of the exploded graphite and dendrite graphite that is relevant to the graphite floatation.