Flaw Detection in Near Surface of Cast Iron by Eddy Current Testing

Bibliographic Information

Other Title
  • 渦電流試験による鋳鉄表面近傍におけるきずの検出
  • ウズデンリュウ シケン ニ ヨル チュウテツ ヒョウメン キンボウ ニ オケル キズ ノ ケンシュツ

Search this article


  Eddy Current Testing (ECT) was applied to non-destructive evaluation of artificial cracks, 0.25 mm in width made by electro discharge method, and internal defect, 1.6 mm diameter drill hole under the surface, in cast iron. It is important to select suitable frequency and coil for measurement to receive higher SIN signal, because small skin depth caused by ferromagnetism of a matrix limits measurable depth and inhomogeneous structure produces strong noise signal. Measurable crack depth was less than 3 mm when using two coil method. Direction of the crack could be determined from Lissajous patterns of the ECT signal. The signal changed linearly when two coils set in right angle to the crack, but showed curve when two coils set parallel with the crack. On the other hand, detection of internal defect of cast iron was difficult because change in Lissajous patterns of the ECT signal by a drill hole under 0.5 mm from the ground surface was weak as compared to higher noise signal induced by inhomogeneous matrix.



See more

Related Projects

See more


Report a problem

Back to top