Abstract: What is provided is an electric resistance welded steel pipe manufacturing device that is configured to perform welding while forming a strip-shaped steel sheet in a tubular shape and supplying a plasma flow to a pair of abutment end surfaces to perform shielding. The electric resistance welded steel pipe manufacturing device includes a mandrel; and a plasma flow feeder that is provided in the mandrel to supply the plasma flow.

Abstract: An electric resistance welding operation management device manages a welding operation during manufacture of electric resistance welded steel pipe, in which heat is input to a steel plate, that is being conveyed along a specific conveyance direction and formed into a circular tube shape while pressing side faces of the metal plate with a pair of squeeze rolls, to weld together two circumferential direction edge portions of the metal plate converging in a V-shape. The electric resistance welding operation management device includes an image input section that inputs plural images and each including a Vee convergence region of the steel plate. The electric resistance welding operation management device includes a welding point position derivation section that derives the position of a welding point.

Abstract: An electric resistance welding operation management device 100 manages a welding operation during manufacture of electric resistance welded steel pipe, in which heat is input to a steel plate 1, that is being conveyed along a specific conveyance direction and formed into a circular tube shape while pressing side faces of the metal plate 1 with a pair of squeeze rolls 2a, 2b, to weld together two circumferential direction edge portions 11a, 11b of the metal plate 1 converging in a V-shape. The electric resistance welding operation management device 100 includes an image input means that inputs plural images, successively captured over 3 sec and each including a Vee convergence region of the steel plate 1.