对内壁含肋的不锈钢异型管件进行了涡流检测试验。采用外穿过式线圈，通过涡流阻抗平面图分析和数据整理，比较了刻有人工缺陷的不锈钢异型管件和普通管件。结果表明，外穿过式线圈在最佳检测频率时可以检测出异型不锈钢管件表面深0.20 mm的周向槽，同时与异型管件内壁宽10 mm肋的信号分离，检测结果更可靠。

A study on eddy current testing of stainless steel tubes with ribs in the inner wall was addressed. A feed-through coil had been used to separate the heterotypic stainless steel tubes with artificial flaws made by EDM, from the normal ones by the analysis of impedance plane diagram and the data processing. The results revealed that the feed-through coil could inspect the artificial circumferential groove of 0.20 mm in depth at the optimum testing frequency. At the same time, the signal of the circumferential groove and the signal of the heterotypic parts, the inner rib of width 10 mm, of the tubes could be separated, leading to a reliable result.