高镍奥氏体球墨铸铁涡壳铸造工艺优化

Optimization of the Casting Process for Turbine Housing of High-Ni Austenitic Ductile Iron

高镍奥氏体球墨铸铁涡壳铸件竖直摆放浇注时,铸件凝固补缩能力差、出品率低,铸件管壁易形成气孔缺陷。结合铸件缺陷特征和分布情况,通过调整铸件浇注位置并结合Magma软件,分析不同浇注位置对铸件凝固过程的影响,并根据顺序凝固理论判定其工艺可行性,优化了铸造工艺设计方案。结果表明,该方案解决了高镍涡轮壳铸件管壁气孔缺陷,并大幅度提高了铸件的工艺出品率和成品率,经济效益显著。

When the high nickel austenitic ductile iron turbine housing was pouring vertically,the solidification and shrinkage capacity of the castings were poor and the yield was low,and the porosity defects on the tube wall of the casting was easy to form.In combination with casting defects characteristics and distribution,the Magma software was used to adjust casting location and analyze the influence of different casting locations on casting solidification process.According to the theory of sequential solidification,the feasibility of the process was determined and the casting process design scheme was optimized.The results show that the scheme solves the porosity defects of high nickel turbine shell castings,and improves the process yield and yield of castings greatly,with remarkable economic benefits.