Abstract: (A) first data for defect amount estimation for the guided wave of a first frequency is obtained, the data indicating a relationship among amplitude of the reflected wave, a defect cross-sectional area and a defect width. (B) second data for defect amount estimation for the guided wave of a second frequency is obtained, the data indicating a relationship among amplitude of the reflected wave, a defect cross-sectional area and a defect width. (C) a guided wave of the first frequency is generated, and amplitude of a reflected wave is detected as first amplitude. (D) a guided wave of the second frequency is generated, and amplitude of a reflected wave is detected as second amplitude. (E) on a basis of the first and second data and the first and second amplitude, a defect cross-sectional area and a defect width of the defect part are estimated.

Abstract: A testing method using a guided wave generates a guided wave to propagate through a subject as a testing target in a longitudinal direction of the subject, detects a reflected wave of the guided wave and examines the subject on the basis of the reflected wave. The testing method includes the steps of (A) obtaining data for defect amount estimation beforehand indicating a relationship between a defect amount of the subject and a magnitude of a reflected wave, (B) generating a guided wave so as to propagate through the subject, and detecting a reflected wave of the guided wave, and (C) estimating a defect amount of the subject on the basis of the data for defect amount estimation obtained at (A) and the magnitude of the guided wave detected at (B).

Abstract: Welding quality of a welding section W welded by laser welding is determined by acquiring an image of the welding section W and its surrounding region by means of a high-speed camera 11, analyzing, as parameters, the number of spatters P per unit length and the area of a high-luminance region in the acquired image by means of an analyzer 12, and comparing the analyzed parameters with respective comparison tables created beforehand, to determine the welding quality of the welding section Wa. Information on the welding quality of the welding section W is displayed on a monitor 13. Not only the laser welding quality of the welding section can be determined but also in-process shearing strength prediction as well as in-process fracture mode prediction can be performed, thus enabling quality control matching high-speed and high-precision laser welding.

Abstract: There are provided a laser diode, an irradiating section that applies an output from the laser diode to a base material in the form of a laser beam and thus melts the surface of the base material while moving the laser beam; a wire feeding section that continuously feeds welding wire to a melted portion of the surface of the base material moving along with the movement of the laser beam emitted from the irradiating section; and a wire heating power source that electrifies the welding wire so that the welding wire located in the melted portion of the base material surface is almost melted. In the case of thick plate welding, it is possible to improve operating efficiency and working accuracy, and in the case of welding a hard-to-weld material such as a high-tensile steel board, it is possible to perform welding while preventing deterioration and fracture of metal structure from occurring.