新型可脱离式隔热板对燃气轮机叶片定向凝固过程的影响  

Using New Baffle to Control Defects in a Vacuum Investment-Cast Ni-Based Turbine Blade

作　　者：秦岭[1] 沈军[1] 杨功显[2] 李秋东[1] 傅恒志[1] 

机构地区：[1]西北工业大学凝固技术国家重点实验室,陕西西安710072 [2]东方汽轮机有限公司,四川德阳618000

出　　处：《稀有金属材料与工程》2016年第5期1284-1289,共6页Rare Metal Materials and Engineering

基　　金：国家重点基础研究发展计划("973"计划)(2013CB035703)

摘　　要：基于有限元模拟软件,对实际工艺参数条件下的大型空心燃气轮机叶片凝固全过程中的温度场、温度梯度、凝固界面的演变进行了模拟仿真,以此为基础研究了雀斑缺陷形成机理及其规律。模拟结果与实验结果取得了良好的吻合。模拟结果表明,在叶片榫头处温度梯度突然降低是导致此处局部缺陷产生的主要原因。并针对该实验现象设计了一种新型隔热板,大幅度提高叶片凝固界面前沿的温度梯度,从而达到避免叶片榫头处产生雀斑缺陷的目的。Based on finite element simulation, temperature field, temperature gradient and the evolution of solidification interface of the large hollow turbine blade in the process of directional solidification were simulated. The results demonstrate that defects are observed at the expanding cross section of casting in directionally solidified nickel-based superalloys. Numerical results indicate that the phenomenon should be attributed to the lower thermal gradient in this zone. Based on these results, a new baffle was proposed. Calculated results reveal that the reasonable design of the new baffle could improve the thermal gradient in the local area. Therefore, this new baffle could more effectively avoid the freckle formation and enhance the mechanical performances of casting.

关 键 词：空心燃气轮机叶片 缺陷 温度梯度 隔热板 凝固界面 

分 类 号：TK476[动力工程及工程热物理—动力机械及工程]