文章信息/Info

Title:

Numerical Simulation of Blade Arrangement on Stray Grains in a Fourth-Generation Single Crystal Superalloy Blade

文章編號:

1674-3962(2024)10-0871-08

作者:

撒世鵬; 楊文超; 秦嘉潤; 張軍; 劉林

西北工業大學 凝固技術國家重點實驗室，西安 710072

Author(s):

SA Shipeng; YANG Wenchao; QIN Jiarun; ZHANG Jun; LIU Lin

State Key Laboratory of Solidification Processing, Northwestern Polytechnical University, Xi’an 710072, China

關鍵詞:

高溫合金; 單晶葉片; 雜晶; 定向凝固; 數值模擬

Keywords:

superalloy;  single crystal blade;  stray grain;  directional solidification;  numerical simulation

分類號:

V232.4；TG132.3

DOI:

10.7502/j.issn.1674-3962.202309002

文獻標志碼:

A

摘要:

針對組模生產第四代單晶高溫合金葉片時由于溫度場不均勻導致的緣板雜晶問題，采用有限元模擬軟件ProCAST對葉片在組模中以不同方式排列時凝固過程的溫度場和晶粒組織進行模擬計算，并且分析了添加引晶桿對雜晶的影響。結果表明，在組模生產時，由于中柱的保溫作用小，導致橫向溫度場不均勻，葉片以0°排列時，緣板邊角靠近中柱，其凝固過程中溫度下降較快，會在邊角形成大的過冷，同時凝固過程的溫度梯度較小，枝晶生長慢，雜晶的形成傾向最大。隨著排列角度的增加，橫向溫度場的不均勻性得到改善，但由于第四代合金形核過冷度小，在緣板位置都會有雜晶形成。添加引晶桿可以消除緣板雜晶，但對于葉片以0°排列時，由于葉片進氣邊靠近中柱，會在引晶桿內產生雜晶。葉片以90°排列時，橫向溫度場較為均勻，添加的引晶桿內不會產生雜晶，同時組模直徑小，可以降低對爐體型腔的尺寸要求，有望成為生產高代次單晶葉片的最優排列方式。

Abstract:

For the problem of stray grain caused by uneven temperature field in the module production of fourth-generation single crystal blades, the finite element simulation software ProCAST was used to simulate the temperature field and grain structure during the solidification process when the blades were arranged in different ways and analyzed the influence of adding crystal guide rod on the stray grain. The results show that transverse temperature field is uneven for the small heat preservation effect of the center pillar in the module production. So when the blades are arranged at 0°, the edge corner of the platform is close to the center pillar, and the temperature drops rapidly during the solidification process, resulting in large undercooling at the edge corner. At the same time, the temperature gradient is small, the dendrites grow slowly, so the formation tendency of stray grain is the largest. With the increase of the angle, the non�瞮niformity of the transverse temperature field is improved, but due to the low degree of nucleation undercooling of the fourth-generation alloy, there will be stray grain formation at the platform position. The stray grain can be eliminated by adding the crystal guide rod, however when the blades are arranged at 0°, due to the inlet edge of the blades near the center pillar, there will be stray grain in the crystal guide rod. When the blades are arranged at 90°, the transverse temperature field is more uniform, there is no stray grain in the crystal guide rod, and the module diameter is small, which can reduce the size requirements of the furnace body, and is expected to become the optimal arrangement for the production of high-generation single-crystal blades.