Abstract: A device for inspecting a moving metal strip includes a first electromagnetic acoustic transducer having an ultrasonic wave emitter. The waves emitted from the emitter are emitted to be incident on a first edge of a surface of the strip, and the emitter is not in contact with the strip. A second electromagnetic acoustic transducer is provided and includes an ultrasonic wave receiver. The waves received emerging from an area of the strip surface toward the receiver, the receiver is not in contact with the strip. A processing unit is coupled to the second electromagnetic acoustic transducer to provide an inspection criterion using a signature of the ultrasonic waves measured. The area is located on the strip such that a wave path between the first edge of the strip and the area is aligned in a linear direction mainly transverse to the direction of movement of the strip.

Abstract: In a method for the spectral analysis of a metal coating layer deposited on the surface of a steel strip, the strip is moved along an arc of the outer surface of a rotating roller with a cylindrical wall guiding the strip by contact. An ablation laser beam is guided into an internal cavity of the cylindrical wall to be placed in optical incidence under a normal axis on the outer surface of the roller on a targeted contact point of the strip and the roller. The beam passes through the wall via a wall opening, which is transparent to the beam. A plasma spectral emission distribution from the laser ablation to the contact point is collected by optical feedback in the direction of the normal axis on the outer surface of the roller and through the opening in order to be guided towards a spectral measurement unit. The normal axis on the outer surface for the optical incidence and feedback is placed in synchronous rotation with the roller.

Abstract: A method and installation for inspecting a butt weld of transverse ends of metal strips held together between first and second jaws along the ends, include leaving an interstice between the jaws for passage of a first transmission channel of incident waves generating ultrasound waves on one surface of the first strip and enabling passage of a second transmission channel of waves emerging from the surface of the second strip. The incident waves of the first channel are generated using laser pulses in an operating state implementing a third channel of waves generated on the surface of the first strip, passing through the weld, and emerging in the second channel. Weld inspection characteristics are identified by analyzing the operating state related to the pulses and a measurement of a signature of a vibration state of the surface of the second strip upon emergence of the waves in the second channel.

Abstract: A method and a device for controlling a thermal cycle of a weld joining one end of a first strip to an end of a second strip, suited to a joining machine of a strip treatment plant. The control device includes connections intended to connect the control device to a central automation system of the strip treatment plant and to the joining machine respectively, so as respectively to allow an exchange of at least one strip data item and an exchange of at least one operating data item. A computer is capable of computing, from the strip and operating data items, at least one thermal parameter of the weld. A weld control and characterization device is capable of controlling the welding as a function of the thermal parameter.

Abstract: A method and a device measure a chemical composition of a liquid metal suitable for coating a steel strip. The method measures a chemical composition of a liquid metal suitable for coating a steel strip for which the liquid metal is formed continuously in a first cavity, and the composition of the liquid metal is measured on a direct measurement surface thereof, for which a specimen of the liquid metal reaching the measurement surface is heated to a chosen temperature so as to isolate principally iron-based impurities from the measurement surface. Several embodiments of devices suitable for implementing the method are also presented.

Abstract: A device for inspecting a moving metal strip includes a first electromagnetic acoustic transducer having an ultrasonic wave emitter. The waves emitted from the emitter are emitted to be incident on a first edge of a surface of the strip, and the emitter is not in contact with the strip. A second electromagnetic acoustic transducer is provided and includes an ultrasonic wave receiver. The waves received emerging from an area of the strip surface toward the receiver, the receiver is not in contact with the strip. A processing unit is coupled to the second electromagnetic acoustic transducer to provide an inspection criterion using a signature of the ultrasonic waves measured. The area is located on the strip such that a wave path between the first edge of the strip and the area is aligned in a linear direction mainly transverse to the direction of movement of the strip.

Abstract: A method and a device for controlling a thermal cycle of a weld joining one end of a first strip to an end of a second strip, suited to a joining machine of a strip treatment plant. The control device includes connections intended to connect the control device to a central automation system of the strip treatment plant and to the joining machine respectively, so as respectively to allow an exchange of at least one strip data item and an exchange of at least one operating data item. A computer is capable of computing, from the strip and operating data items, at least one thermal parameter of the weld. A weld control and characterization device is capable of controlling the welding as a function of the thermal parameter.

Abstract: A method and installation for inspecting a butt weld of transverse ends of metal strips held together between first and second jaws along the ends, include leaving an interstice between the jaws for passage of a first transmission channel of incident waves generating ultrasound waves on one surface of the first strip and enabling passage of a second transmission channel of waves emerging from the surface of the second strip. The incident waves of the first channel are generated using laser pulses in an operating state implementing a third channel of waves generated on the surface of the first strip, passing through the weld, and emerging in the second channel. Weld inspection characteristics are identified by analyzing the operating state related to the pulses and a measurement of a signature of a vibration state of the surface of the second strip upon emergence of the waves in the second channel.

Abstract: In a method for the spectral analysis of a metal coating layer deposited on the surface of a steel strip, the strip is moved along an arc of the outer surface of a rotating roller with a cylindrical wall guiding the strip by contact. An ablation laser beam is guided into an internal cavity of the cylindrical wall to be placed in optical incidence under a normal axis on the outer surface of the roller on a targeted contact point of the strip and the roller. The beam passes through the wall via a wall opening, which is transparent to the beam. A plasma spectral emission distribution from the laser ablation to the contact point is collected by optical feedback in the direction of the normal axis on the outer surface of the roller and through the opening in order to be guided towards a spectral measurement unit. The normal axis on the outer surface for the optical incidence and feedback is placed in synchronous rotation with the roller.

Abstract: A method and a device measure a chemical composition of a liquid metal suitable for coating a steel strip. The method measures a chemical composition of a liquid metal suitable for coating a steel strip for which the liquid metal is formed continuously in a first cavity, and the composition of the liquid metal is measured on a direct measurement surface thereof, for which a specimen of the liquid metal reaching the measurement surface is heated to a chosen temperature so as to isolate principally iron-based impurities from the measurement surface. Several embodiments of devices suitable for implementing the method are also presented.