DD6单晶冷却涡轮叶片模拟试样蠕变寿命研究

摘要

The study of creep life on a modeling specimen of DD6 single crystal cooling turbine blade is carried out. Thin-walled cylindrical specimens with holes are tested to model the air-cooled turbine blade. Specimens without holes are also studied to make comparisons. The experiments are made at 900℃ and 1 000℃. Experimental results show that the creep lives of specimens with holes are longer than those of speci- mens without holes; temperatures and stresses are two main factors which influence the creep life of single crystal; the creep life of the 2.0 mm thick specimens are longer than those of the 1.5 mm thick specimens at the same loading conditions. Thickness and cooling holes are the prime factors which affect the creep life. Scanning Electron Microscopy （SEM） analyses reveal that all the specimens fracture surfaces are mainly made up of dimples and for the specimens with cooling holes, creep deformation concentrates on the region near cooling holes.%研究了DD6单晶冷却涡轮叶片模拟试样中气膜孔对蠕变寿命的影响。分别对带气膜孔和不带气膜孔的薄壁圆管试样进行了蠕变测试，带气膜孔试样作为冷却叶片模拟件，不带气膜孔试样与之比较。900％与1000％的蠕变试验结果表明：在相同应力条件下，壁厚为2．0mm试样的蠕变寿命要比壁厚为1．5mm试样的长，带气膜孔试样的蠕变寿命要比不带气膜孔的长，壁厚和气膜孔是影响模拟试样蠕变寿命的主要因素。通过扫描电镜分析发现：所有试样的蠕变断裂形式以韧窝断裂为主，带气膜孔试样的蠕变变形主要出现在气膜孔区域。