高温合金闭式叶轮的工业CT检测

Industrial CT testing for superalloy enclosed impeller

高温合金闭式叶轮为多层、薄壁、曲面流道的内腔与较大直径轴颈相连的整体复杂结构,使用透照电压不高于450kV的传统X射线照相方法对其进行检测时,存在X射线无法穿透叶轮厚大区域以及无法实现缺陷定位的问题,为此采用高能X射线工业计算机断层扫描(CT)方法对其进行检测。为了验证CT检测方法的缺陷检出能力,在高温合金闭式叶轮上加工已知尺寸的人工孔并进行检测,证明可检出φ0.5mm的孔。最后,对闭式叶轮的实际缺陷进行检测,可实现其内部气孔、缩孔等缺陷的检测和定位。

Superalloy closed impeller has complex structure with multi-layer,thin-walled,curved inner chamber connected with larger diameter journal.When it is tested by traditional X-ray radiography,there are some problems such as X-ray can not penetrate the thick area of impeller and defects can not be located.Therefore,high-energy Xray industrial CT testing method is used.In order to verify the defect detection ability,the artificial holes of known sizes were machined on the closed impeller to be tested.The result shows that the holes ofφ0.5 mm can be detected.By detecting the actual defects in the closed impeller,the internal defects such as pore and shrinkage can be detected and located.