Nippon Steel Sumitomo Metal Corporation

Nippon Steel Corporation

Toshiyuki Suzuma

Yoshiyuki Nakao

Kazunori Anayama

Takahiro Okada

Masami Ikeda

Kenji Imanishi

Makoto Sakamoto

Yoshiyuki Ota

Kenta Sakai

Yoshiyuki Oota

Tetsuya Yadoguchi

Eiji Honda

Shinya Yoshikawa

Tamotsu Nishimine

A method for detecting a metal residue present in an electric-resistance-welded steel pipe includes a first step of inserting the electric-resistance-welded steel pipe into an exciting coil while relatively moving the electric-resistance-welded steel pipe in a longitudinal direction and magnetizing the electric-resistance-welded steel pipe using a direct current at a field intensity capable of magnetizing the electric-resistance-welded steel pipe and the metal residue up to a magnetic saturation state by the exciting coil and a second step of inserting the electric-resistance-welded steel pipe into a detecting coil while relatively moving the electric-resistance-welded steel pipe in the longitudinal direction, detecting an induced electromotive force generated in the detecting coil by a change in a magnetic flux caused by the direct-current magnetization by the exciting coil in the first step as an output signal of the detecting coil, and detecting the metal residue present in the electric-resistance-welded steel pipe on the basis of the output signal of the detecting coil.

Method and device for detecting metal residue in electric-resistance-welded steel pipe

A device of detecting magnetic characteristic change for a long material includes: an exciting coil into which the long material is inserted and which magnetizes the long material in a longitudinal direction; a detecting coil into which the long material is inserted and which detects a magnetic flux generated in the long material due to magnetization by the exciting coil; and a yoke member which has a first opening portion which is positioned on one side of the long material in the longitudinal direction and into which the long material is inserted and a second opening portion which is positioned on the other side of the long material in the longitudinal direction and into which the long material is inserted, and has a shape which is substantially axially symmetrical about an axis passing the first opening portion and the second opening portion, and the exciting coil and the detecting coil are surrounded by the yoke member, the first opening portion, and the second opening portion.

Device and method of detecting magnetic characteristic change for long material

A magnetic testing apparatusaccording to the present invention comprises: a first magnetizing devicefor applying a DC bias magnetic field to a test object P in substantially parallel to the direction in which a flaw F to be detected extends; a second magnetizing devicefor applying an AC magnetic field to the test object P substantially perpendicularly to the direction in which the flaw F to be detected extends; and a detecting devicefor detecting leakage flux produced by the magnetization of the test object P accomplished by the first magnetizing deviceand the second magnetizing device

Magnetic testing method and apparatus

A defect inspecting apparatus includes a first light source, a first image capture device that receives the reflection light emitted from the first light source and reflected by the outer peripheral surface of a lip part to grab the image of the outer peripheral surface of the lip part, a second light source, a second image capture devicethat receives the reflection light emitted from the second light source and reflected by a load face to grab the image of the load face, a third light source, a third image capture device that receives the reflection light emitted from the third light source and reflected by a thread bottom face inspection zoneto grab the image of the thread bottom face inspection zone, and an inspection device for inspecting defects by processing the captured images grabbed by the first to third image capture devices.

Defect inspecting apparatus

The present invention has its objective to provide a defect classification apparatus which suppresses over-fitting and accurately classify the defect type of a defect. A defect classification apparatus is provided in which a data point indicating feature information of a defect to be classified having an unknown defect type is mapped to a point in a mapping space having a dimensional number higher than the number of features constituting the feature information, and the defect type of the defect to be classified is classified based on in which of two regions of defect type, which are formed by separating the mapping space by a decision boundary, the mapped point is located, wherein a discriminant function indicating the decision boundary is determined by adopting a weight which minimizes the sum of the classification error, which corresponds to the accuracy in classifying a training defect dataset, and a regularization term, which has a positive correlation with the dimensional number of the decision boundary, as the weight for each feature constituting the discriminant function.

Defect classification apparatus

A magnetic testing apparatus has a magnetizing device applying a rotating magnetic field to a material to be tested, a testing signal detecting device, and a signal processing device applying signal processing to the testing signal. The signal processing device has a first synchronous detecting device detecting a testing signal by using the first current as a reference signal, a second synchronous detecting device detecting an output signal of the first synchronous detecting device by using the second current as a reference signal to extract a candidate flaw signal, and a testing image display device displaying a testing image in which each of pixels has a gray level corresponding to an intensity of the candidate flaw signal at each of positions of the material to be tested, and a phase of the candidate flaw signal at each of the positions is capable of being identified.

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Tokyo, Japan

Toshiyuki Suzuma