K418B涡轮导向器熔模离心浇注工艺研究

Centrifugal Investment Casting Process of K418B Turbine Guide

针对某K418B涡轮导向器精密铸造(重力铸造)条件下易出现叶片排气边欠铸与粗大柱状晶缺陷问题,在导向器叶片制壳后采用离心铸造浇注并进行模拟仿真、实际浇注验证及晶粒度检验等研究。结果表明,采用离心铸造工艺,可以有效提升导向器的充型能力,解决了排气边欠铸缺陷;同时在离心力场的作用下,叶片在凝固过程中形成了较细小的等轴晶,从根本上抑制了粗大柱状晶缺陷的产生,提高了导向器的综合力学性能。

Aiming at the problems of misrun and coarse columnar crystal defects at the exhausting side of a K418 B turbine guide under gravity investment casting,the centrifugal casting process was designed and simulated,and actual casting verification as well as grain size observation of the guide were carried out.The results show that the centrifugal casting process can improve effectively the filling capacity of the guide and eliminate the casting defects at the exhaust side.At the same time,under the action of centrifugal force field,fine equiaxed grains are formed in the blade during the solidification process,which fundamentally inhibits the formation of coarse columnar crystal defects and improves the comprehensive mechanical properties of the guide.