DZ125定向凝固涡轮叶片不同部位力学性能研究

Study on Mechanical Properties of DZ125 Directional Solidification Turbine Blades in Different Positions

从DZ125定向凝固空心涡轮叶片割取小尺寸试样,并进行两种温度(980℃和1050℃)下单轴拉伸试验以及980℃、219 MPa下的蠕变持久试验。作为对比,同时从DZ125板材上割取小尺寸试样并进行试验。结果表明,相比于标准试件,从叶片上取得的试件的拉伸极限强度明显降低,持久寿命时间也大为缩短;与板材试件相比,从叶片上取得的试件拉伸极限强度和持久寿命也较低,表明涡轮叶片存在局部力学性能弱化。采用标准试件试验数据设计定向凝固涡轮叶片并不能准确表征叶片局部力学性能。小试样试验可作为研究涡轮叶片不同部位力学性能差异的可行方法。

Miniature specimens were cut from DZ125 directional solidification turbine blades. The uniaxial tensile test was carried out at 980℃ and 1050℃, and the creep rupture test was carried out under 980℃ and 219MPa condition. As contrast, another miniature specimens were cut from the DZ125 plate in the same condition and the experiments were carried out. The results show that compared with standard samples, the tensile ultimate strength of the specimen cut from blades reduces significantly and creep rupture life is shortened apparently. Compared with plate specimens, the tensile ultimate strength and creep rupture life of the specimens cut from blades are lower, which indicate that the turbine blades generate the reduction of local mechanical properties. Using the experimental data of standard specimens to design directional solidification turbine blade can not accurately characterize the local mechanical performance of the blade. The miniature specimen experiments are feasible methods to study the mechanical performance difference of turbine blades in different positions.