Eddy current testing is a technique for electromagnetic non-destructive testing and evaluation of conductive materials.This study focuses on finite element simulation analysis of eddy current distribution in the surface defect areas of a specimen at a room temperature of 25 ℃.It proposes a method for detecting surface defects in conductive materials at elevated temperatures of 100 ℃ and 150 ℃ through changes in the impedance of eddy current sensor coils.The coil impedance measurements are carried out under both room temperature and elevated temperatures

producing corresponding 3D surface color maps of impedance.These maps are used to identify defects by analyzing the amplitude and phase of the surface impedance of the test piece.The experiments demonstrate that variations in the eddy current sensor coil's impedance can ascertain the presence of surface defects in the conductive materials when exposed to elevated temperatures.The study also establishes a correlation between defects and coil impedance at different temperatures.