公开(公告)号：US20220097163A1

公开(公告)日：2022-03-31

申请号：US17422542

申请日：2020-03-06

Applicant: NIPPON STEEL CORPORATION

Inventor： Noboru HASEGAWA ,  Takashi MIYAKAWA ,  Michimasa MUKAI ,  Toshisuke FUKAMI

IPC: B23K11/087 ,  B23K11/36 ,  B23K31/12 ,  B23K11/25

Abstract: A method for monitoring welding of an electric resistance welded steel pipe of the present invention includes: an image acquisition step in which, when an electric resistance welded steel pipe is welded, a V-convergence portion including an edge detection area and a V-convergence point, and a welding portion including a position where a molten steel starts to be discharged from an inside of a wall thickness and a bead, are imaged to obtain a captured image; a determination information acquisition step in which the captured image is image-processed, and a molten length from the V-convergence point to the position where the molten steel starts to be discharged or a molten width of the welding portion or a combination thereof is acquired as a determination information; and a determining step in which it is determined whether a cold welding has occurred by comparing the determination information with a determination threshold value set in advance for each wall thickness of the electric resistance welded steel pipe.