Research on High Resolution Stress Corrosion Crack Detection Based on Remote Field Eddy Current Non-Destructive Testing

ABSTRACT

Although remote field eddy current had achieved successive application in pipes and tubes non-destructive testing, the poor ability and sensitivity to axial crack such as stress corrosion crack prevented its further application. A novel high resolution remote field eddy current detection method which can be suitable for axial crack especially stress corrosion crack detection was proposed and verified by simulation and experiment. First of all, conventional detection ability of remote field eddy current for crack in different directions was researched with detail. Aside from this, applicability of orthogonal magnetic filed in remote field eddy current was analyzed and simulated by finite element method, and appropriate configuration using to generating orthogonal magnetic fields for tubular structure was discussed and verified. Thirdly, design of detection system including key parameters selection and detection coil mode were researched. At last, proposed high resolution detection system were verified experimentally using various type defects, such as parallel axial crack and real stress corrosion crack. From the above research, conclusions were drawn as followed: the detection ability and sensitivity of proposed remote field eddy current detection system could be improved significantly compared with conventional system, especially for axial crack which was not easily to detect, and real stress corrosion crack could be detected and evaluated successively.

Keywords:

Detection, finite element simulation, non-destructive testing, remote field eddy current, stress corrosion crack.