Abstract: A metal detecting device includes: a transfer section that transfers an inspection target object, along a path that passes between a first magnet and a second magnet; a first magnetic sensor that is arranged so as to be aligned with the first magnet and that outputs a first signal; and a second magnetic sensor that is arranged so as to be aligned with the second magnet and that outputs a second signal, whether or not the inspection target object contains metal being determined on the basis of strength of the first signal and a phase difference between the first signal and the second signal.

Abstract: A management device includes: an acquisition unit that acquires inspection result data indicating an inspection result of each of a plurality of workpieces and processing condition data indicating a processing condition used for processing each of the plurality of workpieces; an analysis unit that selects a specific parameter correlated with the inspection result among a plurality of processing parameters; and a prediction unit that predicts predict whether or not the processing device will become abnormal in future based on a temporal change in a value of the specific parameter.

Abstract: A surface property evaluation method includes a measurement step for acquiring the distribution of impedance in the depth direction of a test piece, and an evaluation step for evaluating the surface treatment state in the depth direction and wherein the evaluation step includes: a step for creating a reference measurement value group by preparing untreated sample, good sample, and sample to be evaluated, and calculating an impedance ratio ?1 at each frequency for the untreated sample and good sample impedances; a step for creating an evaluation measurement value group by calculating an impedance ratio ?2 for the impedances of untreated sample at each frequency relative to the sample to be evaluated impedances; and a step for evaluating the surface treatment state of a sample to be evaluated by comparing a reference measurement value group with the evaluation measurement value group.

Abstract: An embodiment identifies a cause of change in magnetic permeability of an object under inspection and evaluates the state of surface treatment(s) of the object under inspection with high accuracy. An embodiment of the method includes preparing a non-destructive inspection apparatus; placing the object under inspection; generating eddy current in the object under inspection; continuously changing the penetration depth of an AC magnetic field in the object under inspection; calculating the value of impedance at each penetration depth in the object under inspection; and evaluating the state of the surface treatment(s) by: calculating the ratio between the value of impedance at each penetration depth in the object under inspection and the value of impedance at a corresponding penetration depth in steel which has not been subjected to a surface treatment; and identifying a cause of a change in magnetic permeability of the object under inspection based upon the calculated ratio.

Abstract: The present invention provides a surface property inspection method including a step of setting a resistance ratio between resistors R1 and R2 of an AC bridge circuit 20 in a surface properly inspection apparatus 1. The step includes a step for placing a non-surface-treated reference test pieces S on a reference detector 22 and an inspection detector 23 and measuring a first setting output signal while changing the resistance ratio ?, a step for placing the reference test piece S on the reference detector 22, placing a surface-treated setting test piece on the inspection detector 23, and measuring a second setting output signal while changing the resistance ratio, a step for calculating the differential value between the first and second output signals, and a step for setting the resistance ratio so that the absolute value of the differential value is maximized.

Abstract: To provide a surface characteristics evaluation method that evaluates the residual stress in a subject made of steel material subjected to a surface modification treatment. A surface characteristics evaluation method includes a step of preparing a surface characteristics evaluation apparatus, a step of placing the subject in such a manner that an alternating magnetic field induced by a coil of the surface characteristics evaluation apparatus permeates into the steel material, a step of generating an eddy current in the subject, a step of successively changing the alternating magnetic field applied to the coil, a step of calculating the impedance Z1 for each of different frequencies from the potential difference across the coil and the value of the current flowing through the coil, a step of performing computation based on the impedance Z1, and a step of evaluating the residual stress in the steel material based on the computation result.

Abstract: To provide a surface characteristics evaluation apparatus and a surface characteristics evaluation method that evaluate the residual stress in a steel material subjected to a surface modification treatment by considering the distribution thereof in the depth direction. The surface characteristics evaluation apparatus includes an oscillator, a detector, and a measuring instrument. The steel material is placed to abut against or close to a coil in the detector. The oscillator applies an alternating current to the coil, and computation is performed based on a signal indicating an electric characteristic of the coil. The residual stress in the steel material is evaluated by performing this operation while successively changing the frequency of the alternating current. The coil is configured to have a self-resonant frequency higher than the operating frequency.

Abstract: To provide a surface characteristics inspection method of inspecting a heat treatment on a steel product subjected to a surface treatment in a nondestructive manner. A surface characteristics inspection apparatus is used which includes an alternating-current bridge circuit, an alternating-current power supply that supplies an alternating-current power to the alternating-current bridge circuit, and an evaluation device that evaluates the surface characteristics of a subject, which is a steel product subjected to a heat treatment, based on an output signal of the alternating-current bridge circuit. Coils of a reference detector and an inspection detector in the bridge circuit are energized to produce an alternating-current magnetism to induce an eddy current in a reference subject and the subject, respectively, and the electromagnetic characteristics of the subject obtained in the state where the reference detector detects a reference state is output as a first output signal.

Abstract: A surface property evaluation method includes a measurement step for acquiring the distribution of impedance in the depth direction of a test piece, and an evaluation step for evaluating the surface treatment state in the depth direction and wherein the evaluation step includes: a step for creating a reference measurement value group by preparing untreated sample, good sample, and sample to be evaluated, and calculating an impedance ratio ?1 at each frequency for the untreated sample and good sample impedances; a step for creating an evaluation measurement value group by calculating an impedance ratio ?2 for the impedances of untreated sample at each frequency relative to the sample to be evaluated impedances; and a step for evaluating the surface treatment state of a sample to be evaluated by comparing a reference measurement value group with the evaluation measurement value group.

Abstract: To provide a surface property inspection sorting apparatus, system, and method capable of efficiently performing steps to evaluate the surface properties of spring-shaped members. A surface property inspection and sorting apparatus 1 includes a surface property inspection device, a measuring member for measuring the surface properties of the spring-shaped members M, and a sorting means for sorting the spring-shaped members into good and bad parts. The measuring member is constituted so that spring-shaped members can pass through an inspection detector, and the surface properties of the spring-shaped member can be evaluated and a pass/fail judgment made by a surface property inspection device based on output signals output from an AC bridge circuit while the spring-shaped member passes through the inspection detector.

Abstract: The present invention provides a surface property inspection method including a step of setting a resistance ratio between resistors R1 and R2 of an AC bridge circuit 20 in a surface properly inspection apparatus 1. The step includes a step for placing a non-surface-treated reference test pieces S on a reference detector 22 and an inspection detector 23 and measuring a first setting output signal while changing the resistance ratio ?, a step for placing the reference test piece S on the reference detector 22, placing a surface-treated setting test piece on the inspection detector 23, and measuring a second setting output signal while changing the resistance ratio, a step for calculating the differential value between the first and second output signals, and a step for setting the resistance ratio so that the absolute value of the differential value is maximized.

Abstract: To provide a surface characteristics evaluation method that evaluates the residual stress in a subject made of steel material subjected to a surface modification treatment. A surface characteristics evaluation method includes a step of preparing a surface characteristics evaluation apparatus, a step of placing the subject in such a manner that an alternating magnetic field induced by a coil of the surface characteristics evaluation apparatus permeates into the steel material, a step of generating an eddy current in the subject, a step of successively changing the alternating magnetic field applied to the coil, a step of calculating the impedance Z1 for each of different frequencies from the potential difference across the coil and the value of the current flowing through the coil, a step of performing computation based on the impedance Z1, and a step of evaluating the residual stress in the steel material based on the computation result.

Abstract: The present invention provides a surface property inspection method and apparatus for inspecting the surface properties of a test object subjected to two stages of shot peening. The present invention is an apparatus 1 includes an AC power supply, an AC bridge circuit, and an evaluation apparatus. The AC bridge circuit is constituted by a variable resistor, a reference detector and inspection detector. The inspection detector includes a coil wound so as to oppose the surface property inspection area of the test object M; an eddy current is excited in the test object M by supplying AC power to the coil. A pass/fail judgment of the first shot peening can be made by inspecting the surface properties of a test object subjected to a second shot peening only after the second shot peening is completed.

Abstract: To provide a surface characteristics inspection method of inspecting a heat treatment on a steel product subjected to a surface treatment in a nondestructive manner. A surface characteristics inspection apparatus is used which includes an alternating-current bridge circuit, an alternating-current power supply that supplies an alternating-current power to the alternating-current bridge circuit, and an evaluation device that evaluates the surface characteristics of a subject, which is a steel product subjected to a heat treatment, based on an output signal of the alternating-current bridge circuit. Coils of a reference detector and an inspection detector in the bridge circuit are energized to produce an alternating-current magnetism to induce an eddy current in a reference subject and the subject, respectively, and the electromagnetic characteristics of the subject obtained in the state where the reference detector detects a reference state is output as a first output signal.

Abstract: To provide a surface characteristics evaluation apparatus and a surface characteristics evaluation method that evaluate the residual stress in a steel material subjected to a surface modification treatment by considering the distribution thereof in the depth direction. The surface characteristics evaluation apparatus includes an oscillator, a detector, and a measuring instrument. The steel material is placed to abut against or close to a coil in the detector. The oscillator applies an alternating current to the coil, and computation is performed based on a signal indicating an electric characteristic of the coil. The residual stress in the steel material is evaluated by performing this operation while successively changing the frequency of the alternating current. The coil is configured to have a self-resonant frequency higher than the operating frequency.

Abstract: To provide a surface property inspection device and method capable of inspecting the surface treatment state of treated material subjected to surface treatments. A surface property inspection device 1 includes an AC power supply 10, an AC bridge circuit 20, and an evaluation apparatus 30, and the AC bridge circuit 20 is formed by a variable resistor 21 with a distribution ratio of ?, a reference detector 22, and an inspection detector 23. The inspection detector 23 includes a coil 23b wound so as to oppose the surface property inspection area of the test object M; an eddy current is excited in the test object M by supplying AC power to the coil 23b. A reference test object S with the same structure as the test object M is placed in the reference detector 22 to cancel inspection environment effects.