燃机透平叶片热裂缺陷的形成机理研究  

Formation Mechanism of Thermal Crack Defects in Gas Turbine Blades

作　　者：郭雄 陶飞[1,2] 史卫杰 张琼元[1,2] 杨照宏 Guo Xiong;Tao Fei;Shi Weijie;Zhang Qiongyuan;Yang Zhaohong(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》2021年第11期1365-1369,共5页Special Casting & Nonferrous Alloys

摘　　要：以燃机导向叶片为研究对象,采用精铸工艺成形叶片。对叶片热裂纹位置取样分析,研究了热裂纹缺陷的宏、微观形貌。采用DSC及THERMO-CALC分析了Mar-M247合金的凝固区间特性,同时,采用ProCAST软件模拟了叶片凝固过程的温度场、应力场,阐述了热裂纹形成的物理场特点及形成原理。结果表明,合金凝固区间特性是形成热裂纹的先决条件,而枝晶边界周围的约束条件及拉应力是形成热裂纹的必要条件。其中,凝固速率较慢而温度梯度较大的叶片拐角部位(R)为热裂敏感区域,凝固速率较快、拉应力较大的叶盆部位为热裂非敏感区域。Taking the gas turbine guide blade as the research object,the hot crack of blade produced by the investment casting process was analyzed,and the macro and micro morphology was investigated.DSC and THERMO-CALC were used to analyze the characteristics of the solidification interval of Mar-M247 alloy.Meanwhile,the temperature field and stress field of the blade solidification process were calculated combined with the numerical simulation software ProCAST,and the physical field characteristics and formation mechanism of thermal crack were described.The results indicate that the characteristics of the alloy solidification interval is the prerequisites for the formation of hot cracks,and the constraint conditions and tensile stress around the dendrite boundaries are the essential conditions.Thereinto,the R corner of the blade is the most sensitive area of thermal crack with slower solidification rate and larger temperature gradient,and the basin position with the faster solidification rate and the larger tensile stress is the thermal crack insensitive area.

关 键 词：燃机叶片 热裂纹 形成机理 

分 类 号：TG132.32[一般工业技术—材料科学与工程] TG250.6[金属学及工艺—合金]