Abstract: The present invention relates to an ultrasonic testing apparatus with a variable frequency, which can automatically change the frequency according to thickness and thereby detect internal defects in objects having various thicknesses. The ultrasonic testing apparatus may comprise: a nozzle jetting a medium toward an object so as to form a medium column; and a plurality of probes disposed in the nozzle so as to generate ultrasonic waves.

Abstract: The present invention provides an apparatus for cutting a material, comprising: a frame body installed on a conveying path of a material; a cutting means, mounted on the frame body, for cutting an end portion of the material being conveyed; a laser preheating means for preheating the material by irradiating a laser beam onto the material before being conveyed to the cutting means; and a blocking and reflection means for blocking the laser beams reflected to the cutting means and re-reflecting the laser beam to the material.

Abstract: A side trimming device according to an embodiment of the present invention may comprise: a cutting unit for mechanically cutting a transferred steel plate; a groove forming unit for forming a groove in a cutting-scheduled area in front of the cutting unit with reference to the steel plate transfer direction; and a washing unit arranged adjacent to the groove forming unit so as to suction molten material accumulating in the groove in the side direction of the steel plate.

Abstract: A dimension measuring device includes: a rail for moving two sheets of material; a plurality of range finders arranged at a preset interval along a direction of traveling of the material, so as to measure a distance from side surfaces of the material; and an imaging device for taking images between the first and second range finders, which are disposed at the first and second locations with reference to the entry side of the material, respectively.

Abstract: An apparatus for measuring a crystal grain size of a steel plate according to an embodiment of the present invention may comprises: an ultrasound generating unit for applying ultrasound to one point of a steel sheet; an ultrasound receiving unit for receiving propagated ultrasound at two points spaced different distances apart from the one point of the steel sheet; and a crystal grain size calculating unit for calculating an average crystal grain size of the steel sheet according to intensities of the ultrasound propagated to the two points and an attenuation coefficient according to a distance between the two points. The apparatus can calculate an attenuation coefficient, regardless of a change of surface characteristics, such as surface reflectance, surface roughness, or the like.

Abstract: The present invention provides an apparatus for cutting a material, comprising: a frame body installed on a conveying path of a material; a cutting means, mounted on the frame body, for cutting an end portion of the material being conveyed; a laser preheating means for preheating the material by irradiating a laser beam onto the material before being conveyed to the cutting means; and a blocking and reflection means for blocking the laser beams reflected to the cutting means and re-reflecting the laser beam to the material.

Abstract: A side trimming apparatus including a cutting unit which is installed on at least one side of a steel plate being transferred and trims a side of the steel plate by mechanical cutting and a laser processing unit which is installed in front of the cutting unit and emits a laser beam to a portion of the steel plate to be cut to form a groove at the portion to be cut or preheat the portion to be cut, and a side trimming method using the same are provided.

Abstract: The present invention relates to a dimension measuring device and a dimension measuring method, the dimension measuring device comprising: a moving unit for moving two sheets of material; a plurality of range finders installed at a preset interval along the direction of traveling of the material, so as to measure the distance from the side surfaces of the material; and an imaging device installed to take images between the first and second range finders, which are installed at the first and second locations with reference to the entry side of the material, respectively.

Abstract: A device according to an embodiment of the present invention for detecting an internal flaw in a steel plate by using a height-adjustable ultrasonic sensor may comprise: a spray nozzle installed a certain distance apart from the bottom of a steel plate, for spraying a medium toward the steel plate and forming a medium column; an ultrasonic sensor installed inside the spray nozzle, for transmitting and receiving ultrasonic waves for detecting flaws in the steel plate through the medium column; a flaw detecting unit for detecting the presence of internal flaws in the steel plate on the basis of the transmitted and received ultrasonic waves; and a driving unit installed inside the spray nozzle, for adjusting the distance between the ultrasonic sensor and the steel plate according to the thickness of the steel plate.

Abstract: An apparatus and a method for ultrasonic detection are provided. The apparatus includes an injection nozzle which is installed below a steel plate being transported and forms a medium column by jet a medium toward the steel plate, an ultrasonic probe which is installed in the injection nozzle and transmits and receives ultrasonic waves for detecting flaws in the steel plate through the medium column, and a medium circulation unit which reclaims the medium which falls from the medium column and circulates the reclaimed medium to the injection nozzle.

Abstract: An apparatus and a method for ultrasonic detection are provided. The apparatus includes an injection nozzle which is installed below a steel plate being transported and forms a medium column by jet a medium toward the steel plate, an ultrasonic probe which is installed in the injection nozzle and transmits and receives ultrasonic waves for detecting flaws in the steel plate through the medium column, and a medium circulation unit which reclaims the medium which falls from the medium column and circulates the reclaimed medium to the injection nozzle.

Abstract: A side trimming apparatus including a cutting unit which is installed on at least one side of a steel plate being transferred and trims a side of the steel plate by mechanical cutting and a laser processing unit which is installed in front of the cutting unit and emits a laser beam to a portion of the steel plate to be cut to form a groove at the portion to be cut or preheat the portion to be cut, and a side trimming method using the same are provided.

Abstract: There is provided a method and apparatus for plating high strength steel such as advanced high strength steel (AHSS) after irradiating the high strength steel with at least one of laser light and plasma to remove Si/Mn/Al oxides from the surface of the high strength steel, modify the surface of the high strength steel, or make the surface of the high strength steel suitable for a post process such as a zinc plating process. For this, a plating method includes heating high strength steel; treating a surface of the high strength steel with plasma to remove at least one of a Mn oxide, an Al oxide, and an Si oxide formed on the surface of the high strength steel during the heating of the high strength steel; and plating the surface-treated high strength steel.

Abstract: There is provided a method and apparatus for plating high strength steel such as advanced high strength steel (AHSS) after irradiating the high strength steel with at least one of laser light and plasma to remove Si/Mn/Al oxides from the surface of the high strength steel, modify the surface of the high strength steel, or make the surface of the high strength steel suitable for a post process such as a zinc plating process. For this, a plating method includes heating high strength steel; treating a surface of the high strength steel with plasma to remove at least one of a Mn oxide, an Al oxide, and an Si oxide formed on the surface of the high strength steel during the heating of the high strength steel; and plating the surface-treated high strength steel.

Abstract: An optical wireless communications network connects a plurality of communication cells, which are defined by dividing a local communication area, for enabling optical wireless communication in each of the communication cells. An optical signal transmitter is installed in each communication cell for irradiating the cell with a data-modulated optical signal to perform data transmission to a terminal located therein. The optical signal transmitter comprises an optical signal source for outputting the data-modulated optical signal, and an optical signal diffuser with a concave inside surface facing the output end of the optical signal source for diffusing and reflecting the data-modulated optical signal to irradiate the cell.