高镍奥氏体球墨铸铁涡壳的开发

摘要

针对D-3.5和D-5S两种材质的高镍奥氏体球铁涡壳进行了试验研究,认为奥氏体枝晶发达才是高镍球铁出现碎块状石墨和显微缩松难以消除的根本原因.通过MAGMA模拟软件进行了铸造工艺模拟分析,优化了铸造工艺,缩短了开发周期,降低了成本.采用长效的Si-Ba和Si-Sr孕育剂的多次孕育,并加入微量的Sn和Sb元素,同时严格控制化学成分、出铁温度等关键参数,解决了球化不稳定、碎块石墨和显微缩松等问题,成功完成了高镍奥氏体球铁涡壳的开发,掌握了高镍奥氏体球铁的批量生产技术.%Two kinds of high nickel austenite ductile iron (D-3.5 and D-5S) turbocharger housing were researched, and a large number of austenitic dendrites were deem to the basic reason of chunky graphite and porosity. By simulation of casting process with the MAGMA software, the casting process was optimized; development cycle and the cost were reduced. Using long-acting nucleating agent such as Si-Ba and Si-Sr, adding trace of Sn and Sb element, and strictly controlling the key parameters of the chemical composition, the tapping temperature and the pouring temperature, etc., we solved the problems of the spheroidizing instability, chunky graphite and porosity, so successfully completed the development of the austenite ductile iron turbocharger housing and mastered the batch production technology of the high nickel austenite ductile iron.