重型燃机大尺寸叶片定向凝固组织模拟  

Directional Solidification Microstructure Simulation of Large Size Blade of Heavy Gas Turbine

作　　者：李海松 杨啊涛[1,2] 张琼元 杨照宏 杨功显[1,2] Li Haisong;Yang Atao;Zhang Qiongyuan;Yang Zhaohong;Yang Gongxian(State Key Laboratory of Long-life High Temperature Materials;Dongfang Electric Corporation Dongfang Turbine Co.,Ltd.)

机构地区：[1]长寿命高温材料国家重点实验室 [2]东方电气集团东方汽轮机有限公司

出　　处：《特种铸造及有色合金》2020年第9期980-984,共5页Special Casting & Nonferrous Alloys

摘　　要：采用CAFE模型对某重型燃机大尺寸动叶片定向凝固组织进行了数值模拟。结果表明,叶根朝下组模时,柱状晶尺寸细小,偏离度和发散度较小,叶根晶粒尺寸细小,叶顶晶粒尺寸粗大;叶顶朝下组模时,柱状晶粗大,偏离度和发散度较大,叶顶晶粒细小,叶根晶粒粗大。抽拉速率对柱状晶组织的影响与组模方式相关性不大,抽拉速率越大,柱状晶尺寸越小,偏离度和发散度越小。试生产发现,数值模拟结果和试验结果符合较好。A three dimensional cellular automaton-finite element model was established to predict the solidification grain structures of large size blade of heavy gas turbine.The results reveal that the deviation angle and divergence angle of columnar grains are small and columnar crystal is fine when assembled with root down,meanwhile,grain size of blade root is fine,while grain size of blade top is coarse.However,the deviation angle and divergence angle of coarse columnar grain are large when assembled with tip down,meanwhile grain size of blade root is coarse,while grain size of blade top is fine.In addition,the effects of withdrawal rate on solidification structure are independent on the assembled modes.With the withdrawal rate increasing,the columnar grain size and angle of deviation and divergence are decreased.The numerical simulation results are in good agreement with the experimental ones.

关 键 词：重型燃机 大尺寸动叶片 定向凝固 偏离度 发散度 

分 类 号：TG249.5[机械工程—精密仪器及机械] TP311[金属学及工艺—铸造]