Sumitomo Metal Industries, Inc.

Takahide Sakamoto

Tatsuo Hiroshima

Toshio Shiraiwa

Ichiroh Ohgaki

Noriyuki Matsubara

Kenichi Matsui

Kenichi Miyata

A method and apparatus for measuring a liner thickness of a zirconium liner provided at the inner surface of a zirconium alloy tube, the principle of measurement of which is to insert coils into the tube to generate an eddy current, detect the impedance component in the direction perpendicular to the direction of coil impedance change caused by the lift-off variation between the coils and the inner surface of tube, and obtain the liner thickness on the basis of the impedance component. In a case where the lift-off variation is larger, the impedance component in the direction of coil impedance change caused by the lift-off variation is detected, so that the component is used to correct the impedance component perpendicular to the same, thereby obtaining the liner thickness in accordance with the corrected values.

Zirconium liner thickness measuring method and an apparatus therefor for

A flaw detection apparatus for detecting flaws at the outer surface of a product, such as a steel bar, wire or steel pipe, which is round in section and produced by the hot rolling, by use of a probe of non-contact type and rotating around the product to be inspected, the apparatus providing a means for suppressing vibrations of an object to be inspected, a means for measuring a distance (lift-off) between the object to be inspected and the probe, and a means for carrying out positional control on the basis of the detection result of the lift-off measurement so that the axis of rotation of probe is allowed to be coincident with the axis of object to be inspected. In a case of using the eddy current inspection for the flaw detection, two coils of standard comparison system are used and a mixed signal of a plurality of frequencies is applied to the coils so that a signal obtained by the probe coils suppresses the signal component caused by the lift-off variation and corrects the flaw signal caused by existence of the signal component, thereby eliminating the influence of lift-off variation and enabling measurement with high accuracy.

Rotary probe apparatus for detecting flaws in a test object

Method and apparatus for conditioning of steel surface

Steel surface inspection apparatus

A cutting apparatus lights the surface of a moving hot steel material with lamps, locates any flaw with a video camera or the like, scarfs the surface of the steel material adjacent the flaw with a scarfing torch, measures the depth of the flaw with an eddy current detecting probe or the like, estimates accurately the loss of length due to conditioning size and depth of the flaw with a computer, and cuts the steel material in a predetermined length plus the accurately estimated length corresponding to the loss of length due to conditioning.

Hot steel cutting apparatus

Growing community of inventors

Minoo, Japan

Takahide Sakamoto