透平膨胀机钎焊叶轮超速试验后的检验

钎焊是高速透平膨胀机铝合金闭式叶轮制造中的一种重要方法，有限元分析（FEA）方法可以了解闭式叶轮在离心力场下的应力及变形的3D分布，并预测轮盘与轮盖钎接缝上的应力大小和变化趋势，及叶轮的最大应力发生区域和最大变形产生位置，有限元分析结果表明，叶轮超速试验后，应注意轮盖内孔钎接区域附近微裂纹的检测，同时在轮盖内孔及外缘处测量超速后的残余弹性变形。

INSPECTION OF SPIN-TESTED TURBOEXPANDER BRAZING IMPELLER

Brazing welding is an important method in manufacture of small turboexpander aluminum alloy closed impellers Stress and deformation distribution of three dimensions of closed impeller under centrifugal force field can study by finite element analysis(FEA) The stress variation on brazing line,the maximun stress point and the maximun deformation point of impeller have been predicted It is indicated that tiny cracks near brazing lines and remainder deformations on impeller cover inner hole and outer cylinder should be noted after spin testing