Abstract: A laser welding method includes: forming a melted section in which plural metallic workpieces within a weld region are melted by projecting a first laser beam onto said weld region with parts of the workpieces being set as the weld region when the workpieces are welded; and projecting a second laser beam while the melted section is being solidified or after a solidified section in which the melted section is solidified is formed such that the second laser beam circles around center of the melted section or the solidified section from an irradiation start position deviated from said center toward said center or such that the second laser beam is focused to the center of the melted section or the solidified section from an irradiation start region that includes the center and a periphery thereof.

Abstract: A laser processing apparatus includes: a head main body housing an optical system; and a nozzle that is fastened to the head main body by thread fastening and that applies the laser beam to a workpiece. The nozzle has a nozzle hole through which the laser beam passes. A pressure chamber is formed between the head main body and the nozzle. The pressure chamber is a space surrounded by a bottom surface of the head main body, the bottom surface intersecting with a fastening direction in which the head main body and the nozzle are fastened together by thread fastening, and a bottom surface of the nozzle, the bottom surface intersecting with the fastening direction. The pressure chamber is supplied with air or assist gas. The nozzle has a communication hole that provides communication between the pressure chamber and the nozzle hole.

Abstract: A laser welding method includes: forming a melted section in which plural metallic workpieces within a weld region are melted by projecting a first laser beam onto said weld region with parts of the workpieces being set as the weld region when the workpieces are welded; and projecting a second laser beam while the melted section is being solidified or after a solidified section in which the melted section is solidified is formed such that the second laser beam circles around center of the melted section or the solidified section from an irradiation start position deviated from said center toward said center or such that the second laser beam is focused to the center of the melted section or the solidified section from an irradiation start region that includes the center and a periphery thereof.

Abstract: A welding method according to the invention is a welding method in which welding is performed by emitting a high-energy beam onto a welding object that includes a plurality of overlapped metal sheets. This welding method includes forming a tack weld nugget at a welding point on the welding object, and forming a plurality of final weld nuggets along a virtual closed curve that encircles the tack weld nugget, while leaving the tack weld nugget, at the welding point.

Abstract: A laser surface treatment method for treating a surface of a workpiece having an irregular shape includes radiating a laser so that the surface of the workpiece which is placed in a direction forming an acute angle with respect to the laser becomes an untreated plane. The method also includes scanning with the laser so that the surface of the workpiece which is placed in the direction forming an acute angle with respect to the laser becomes an untreated plane.

Abstract: A welding method according to the present invention is a welding method for irradiating an object to be welded including a plurality of metallic plates that are stacked on each other with a high energy beam and performing welding. The welding method includes: forming a plurality of tack weld nuggets along a virtual closed curve on a part to be welded of the object to be welded; and forming a plurality of main weld nuggets so that the main weld nuggets overlap the plurality of respective tack weld nuggets.

Abstract: Objects to be welded are joined together by laser welding to form adjacent nuggets. When a distance between central axes of the adjacent nuggets is p and a diameter of the adjacent nuggets in the objects to be welded is d, the adjacent nuggets are formed so as to satisfy an equation 1.0<p/d?1.6.

Abstract: A laser welding method includes: projecting a laser beam onto irradiation regions on plural metallic workpieces such that a weld section is formed when the workpieces are joined by laser welding, the weld section being formed of plural nuggets, and each of the irradiation regions being formed with each of the nuggets. The nuggets are sequentially formed by sequentially projecting the laser beam onto the irradiation regions that respectively correspond to the nuggets. The laser beam is projected onto each of the irradiation regions such that an amount of input heat from the laser beam that is projected onto each of the irradiation regions to the workpiece is reduced as the nuggets are sequentially formed.

Abstract: Provided is an electric resistance welding electrode, which comprises an insulated cylinder, an electrode slidably inserted into the insulated cylinder, an urging member configured to apply an advance force to the insulated cylinder, and a stopper configured to set an advance distance of an insulated end surface of the insulated cylinder with respect to an pressing surface of the electrode to a predetermined distance. A receiving recessed portion for receiving a component is defined by the pressing surface retreated by the predetermined distance with respect to the insulated end surface and an inner surface of the insulated cylinder. The electric resistance welding electrode performs welding in one of welding modes consisting of a component welding mode and a spot welding mode.

Abstract: A laser processing apparatus includes: a head main body housing an optical system; and a nozzle that is fastened to the head main body by thread fastening and that applies the laser beam to a workpiece. The nozzle has a nozzle hole through which the laser beam passes. A pressure chamber is formed between the head main body and the nozzle. The pressure chamber is a space surrounded by a bottom surface of the head main body, the bottom surface intersecting with a fastening direction in which the head main body and the nozzle are fastened together by thread fastening, and a bottom surface of the nozzle, the bottom surface intersecting with the fastening direction. The pressure chamber is supplied with air or assist gas. The nozzle has a communication hole that provides communication between the pressure chamber and the nozzle hole.

Abstract: A method of producing a hot-stamped article includes: a forming process of heating a galvanized steel sheet (1) on which a galvanized layer (12) is formed and forming the heated galvanized steel sheet (1) by hot stamping; a removal process of irradiating, after the forming step, an oxide film (13) formed on a surface of the galvanized layer (12) with laser light to remove the oxide film (13); and a coating process of performing, after the removal process, a coating treatment on the galvanized steel sheet (1) formed by hot stamping.

Abstract: A welding method according to the present invention is a welding method for irradiating an object to be welded including a plurality of metallic plates that are stacked on each other with a high energy beam and performing welding. The welding method includes: forming a plurality of tack weld nuggets along a virtual closed curve on a part to be welded of the object to be welded; and forming a plurality of main weld nuggets so that the main weld nuggets overlap the plurality of respective tack weld nuggets.

Abstract: A welding method according to the invention is a welding method in which welding is performed by emitting a high-energy beam onto a welding object that includes a plurality of overlapped metal sheets. This welding method includes forming a tack weld nugget at a welding point on the welding object, and forming a plurality of final weld nuggets along a virtual closed curve that encircles the tack weld nugget, while leaving the tack weld nugget, at the welding point.

Abstract: A laser welding method for welding a plurality of objects to be welded by applying a laser beam scanned by a scanning unit to the plurality of objects to be welded while moving the scanning unit in a welding direction along a welding path, the laser welding method including the steps of: performing a step of preliminary-fixation-welding on a predetermined place in the welding direction of the objects to be welded, and a step of main-welding on a place corresponding to the preliminarily-fixed place of the object to be welded within a scanning range of the scanning unit while moving the scanning unit. Further, when the place corresponding to the preliminarily-fixed place of the object to be welded is main-welded, the place is main-welded in a state where both sides of the place to be main-welded are restrained.

Abstract: A laser surface treatment method for treating a surface of a workpiece having an irregular shape includes radiating a laser so that the surface of the workpiece which is placed in a direction forming an acute angle with respect to the laser becomes an untreated plane. The method also includes scanning with the laser so that the surface of the workpiece which is placed in the direction forming an acute angle with respect to the laser becomes an untreated plane.

Abstract: Provided is a measuring method for measuring laser scanning velocity for a laser beam machining apparatus. The laser beam machining apparatus includes a mirror, and is configured to process a work by irradiating laser. The laser is irradiated by operating the mirror. The measuring method includes measuring processing sound of the work by the laser using the laser beam machining apparatus. Further, the measuring method includes calculating scanning velocity of the laser by analyzing a frequency of the measured processing sound using the laser beam machining apparatus.

Abstract: A laser welding method includes: projecting a laser beam onto irradiation regions on plural metallic workpieces such that a weld section is formed when the workpieces are joined by laser welding, the weld section being formed of plural nuggets, and each of the irradiation regions being formed with each of the nuggets. The nuggets are sequentially formed by sequentially projecting the laser beam onto the irradiation regions that respectively correspond to the nuggets. The laser beam is projected onto each of the irradiation regions such that an amount of input heat from the laser beam that is projected onto each of the irradiation regions to the workpiece is reduced as the nuggets are sequentially formed.

Abstract: A welding method for joining together a plurality of welding objects by overlapping the plurality of welding objects and performing laser welding includes forming a weld by forming a plurality of nuggets along a virtual closed curve on the welding objects, by laser welding. A ratio of a diameter of the nuggets to a pitch dimension between the nuggets that are adjacent to each other is larger than 1/2 and no more than 1.

Abstract: A laser welding method includes: forming a melted section in which plural metallic workpieces within a weld region are melted by projecting a first laser beam onto said weld region with parts of the workpieces being set as the weld region when the workpieces are welded; and projecting a second laser beam while the melted section is being solidified or after a solidified section in which the melted section is solidified is formed such that the second laser beam circles around center of the melted section or the solidified section from an irradiation start position deviated from said center toward said center or such that the second laser beam is focused to the center of the melted section or the solidified section from an irradiation start region that includes the center and a periphery thereof.

Abstract: A welded portion (1) formed at a joint between a plurality of steel plates (10) is formed of a plurality of nuggets (11) arranged along a virtual closed curve (12), and when the thickness of the thinnest steel plate (10) of the steel plates (10) is denoted by t, the diameter d of each nugget (11) is 3 ?t or less, and the pitch p between adjacent nuggets is 2 d or more but no more than 5 d, and the number of nuggets is three or more.