在磁粉检测过程中, 粗糙的工件表面会造成磁粉的堆积, 从而形成过度背景, 这会增加裂纹磁痕的辨识难度, 造成漏检或误检。通过建模分析了表面粗糙度与裂纹漏磁场幅值间的关系, 针对不同粗糙度的表面在磁粉检测过程中呈现出不同磁痕特征的对比, 分析了表面粗糙度对磁粉检测可行性和可靠性的影响。试验结果表明: 表面粗糙度越高, 粗糙表面对磁悬液的润湿滞后作用越明显；表面磁悬液滞留越多, 对磁粉检测的可靠性影响越大。

Magnetic particle testing has been widely used in non-destruction testing of ferromagnetic materials for detecting defects at or near the surface . A rough surface could give rise to the accumulation of the magnetic powder, leading to excessive background which would make the defects harder to recognize and finally cause the missing inspection or wrong results. Analysis about the relationship between surface roughness and magnetic flux leakage of the crack was put forward by establishing models in this paper. The qualitative analysis indicated that surface roughness could influence the reliability of magnetic particle testing to some extent.