Reliability assessment of automated eddy current system for turbine blades

This paper outlines an effort to develop an automated eddy current method assisted by a self-aligned manipulator scanning along the disk rim of a Westinghouse turbine. The light-weighted manipulator was mainly designed for inspecting blades on the L-2 stage disk where root cracks were most frequently found during ISI. A mock-up with changeable blades was used to assess the performance of this technique by a statistical method. Experimental results showed that the POD of this technique agreed well with that originally proposed. The technique was also proven feasible in field trials.