大型风电铸件典型铸造缺陷及防止方法

简要介绍了生产大型风电铸件过程中碰到的缩松、夹渣、碎块状石墨等三种典型铸造缺陷。考虑到风电铸件一般比较厚大及对强韧性的特殊要求，现场生产中对于缩松除了严格控制铸件化学成分、选择纯度较高的原材料以及充分进行球化孕育外，还要合理设计冒口与冷铁，并应用凝固模拟软件对工艺方案进行验证；对于夹渣可以采用脱硫处理、过滤等手段减少一次渣进入铸型，配合浇注系统底注慢浇的方式减少二次渣的形成；对于碎块状石墨，适当增加碳当量（W（CE）=4．3％～4．5％），并控制w（Si）与残余w（Mg），另外有控制地加入Sb对防止碎块状石墨都是有效的措施。

Typical Casting Defects for Large Wind Power Castings and Their Preventation

Three main casting defects, such as shrinkage, dross and chunky graphite caused in production of large-size wind power castings were briefly introduced. Considering the larger thickness and special demand of obdurability for the wind power castings, with regard to shrinkage, besides to control the chemical composition strictly, select purer raw materials and sufficient inoculation after nodulizing, the proper riser and chill was designed, and the process should be checked by solidification simulation. For dross, the desulfurization and filter was used to reduce first dross, and the bottom pouring system and slow pouring was applied to reduce second dross. For chunky graphite, carbon equivalent was raised to 4.3%-4.5%, and Si content and residual Mg content should be controlled. In addition, adding proper Sb is an effective method to prevent chunky graphite.