Influence of Surface Roughness on Eddy Current Testing

To explore the influence of surface roughness on eddy current testing, a series of experiments was applied to work pieces with different surface roughness value Ra. The experiment results show that: for work pieces with rough surface, the detectability of defects is not only dependant on the roughness value but also on the ways of manufacturing and texture. In this paper, the rough surface is equivalent to numbers of defects with depth of Ra. The distribution of magnetic field is analyzed on the basis of the truncation of eddy current caused by equivalent defect. Furthermore, the influence of surface roughness on specimen conductivity is proposed based on the hinder of electron flow caused by equivalent defect.