Abstract:
The principles of testing steel tubes by guided waves based on magnetostrictive effect were introduced. An prototype of experimental system was developed. The modes resulted with stimulating in low frequency range and the axisymmetrical configuration of coils and bias magnetic fields were analyzed. Two types of defects of different sizes were tested using L(0,2) mode. The reflected signal from defects could be identified for through-wall holes of 3.5mm in diameter and above, and notches of 1.5mm in depth and above. The experimental results showed the feasibility of magnetostrictive guided waves in steel tubes testing.