EDDY CURRENT FLAW DETECTION METHOD AND EDDY CURRENT FLAW DETECTION EQUIPMENT FOR ELECTRIC RESISTANCE WELDED TUBE

To provide eddy current flaw detection equipment or the like which can detect a fine defect in a tube manufacturing process, in a manufacturing process of an electric resistance welded tube having the tube making process and a secondary working process.SOLUTION: Eddy current flaw detection equipment 100 related to the present invention comprises a first eddy current flaw detection device 10 detecting an eddy current flaw of an electric resistance welded tube P in a tube making process, and a second eddy current flaw detection device 20 detecting an eddy current flaw of the electric resistance welded tube after a cold stretching process. A first defect volume ratio which is decided by a dimension of a defect for use in a calibration of flaw detection sensitivity or the like in the first eddy current flaw detection device, and a dimension of a detection coil 2 of the first eddy current flaw detection device, and a second defect volume ratio which is decided by a dimension of a defect being a detection object in the second eddy current flaw detection device and a dimension of a detection coil of the second eddy current flaw detection device are calculated in advance. Corrected flaw detection sensitivity which is obtained by correcting the calibrated flaw detection sensitivity on the basis of a ratio of the second defect volume ratio with respect to the calculated first defect volume ratio is set at the first eddy current flaw detection device, and the first eddy current flaw detection device detects the eddy current flaw of the electric resistance welded tube by using the corrected flaw detection sensitivity or the like.SELECTED DRAWING: Figure 1 【課題】造管工程と二次加工工程とを有する電縫鋼管の製造過程において、造管工程で微細な欠陥を検出可能な渦流探傷設備等を提供する。【解決手段】本発明に係る渦流探傷設備１００は、造管工程で電縫鋼管Ｐを渦流探傷する第１渦流探傷装置１０と、冷間抽伸工程後の電縫鋼管を渦流探傷する第２渦流探傷装置２０とを備える。第１渦流探傷装置での探傷感度等の校正に用いる欠陥の寸法と第１渦流探傷装置の検出コイル２の寸法とによって決まる第１欠陥体積比と、第２渦流探傷装置で検出対象とする欠陥の寸法と第２渦流探傷装置の検出コイルの寸法とによって決まる第２欠陥体積比とが予め算出され、第１渦流探傷装置には、校正後の探傷感度等を、算出した第１欠陥体積比に対する第２欠陥体積比の割合に基づき補正した補正後の探傷感度等が設定されており、第１渦流探傷装置は、補正後の探傷感度等を用いて電縫鋼管を渦流探傷する。【選択図】 図１