热损伤会导致铁磁性材料组织、力学性能等发生改变，进而影响承压设备安全性，而表征此类失效模式的方法较少。使用自制涡流检测探头及系统，对不同热损伤程度的试块进行扫查，分析了检测信号(ΔL,ΔR)的变化规律。结果表明：两变化量均随热损伤程度的增加呈递增趋势，且ΔL变化较ΔR明显，根据ΔL可表征热损伤范围和大小。上述结论有望在承压设备安全运行中得到实际应用。

The thermal damage can cause changes of ferromagnetic material microstructure and mechanical property, and further have an impact on pressure equipment safety, whereas the available methods used to test this kind of failure mode are few. The test block with different thermal damage degrees was scanned based on eddy current testing probe and system, and research on the variation of detection signal ΔL and ΔR was conducted. The experimental results show that both of the two variations present an upward trend with the increasing of thermal damage degree, except for that ΔL changes more obviously than ΔR, and the scope and size of thermal damage can be characterized by ΔL. These conclusions are expected to be used in the safe operation of pressure equipment.