Effect of Investment Casting Process on Filling Performance and Grain Structure of K418B Turbine Guide
Author of the article:LI Fei;HOU Zhengqian;ZHAO Yanjie;HAO Xin;LI Zhenfeng;ZHOU Jian
Author's Workplace：Shanghai Key Laboratory for High Temperature Materials and Precision Forming,Shanghai Jiao Tong University,Shanghai 200240,China;National South Aviation Industry Co.,Ltd.,Zhuzhou 412000,China
Key Words：Nickel-based superalloy turbine guide ceramic shell filling performance grain structure
Abstract：
The effects of investment casting pouring system, pouring temperature and shell preheating temperature on filling performance and grain structure of K418 B turbine guide under gravity casting were studied. The results show that on the basis of adjusting the casting process, the temperature field distribution of the cavity is changed by thickening the outer shell of the exhaust side to reduce the cooling speed of the exhaust side of the guide vanes. On the one hand, the filling integrity of the exhaust edge is guaranteed, and on the other hand, the temperature gradient between the exhaust edge and the bulk of the blade thickness is reduced. The grain structure of the whole blade is changed from large size columnar crystal to smaller equiaxed crystal, which improves the comprehensive mechanical properties of the guide.
