| 摘要 |
PROBLEM TO BE SOLVED: To provide a method that can impart I-type butting shape utilizing an existing facility difficult from a viewpoint of facility restrictions and cost restriction in the case of a thick-walled tube in an electric resistance welded tube manufacturing technology.SOLUTION: A strip 1 is continuously put out and roll-formed in tube shape, and then both ends in a sheet width direction are made to butt to perform electric resistance welding. At this time, during a time from putting-out until the start of roll-forming, the strip in a horizontal attitude is subjected to temporary elastic deformation from plate shape into upward projecting bent shape within a cross section in a sheet width direction, and both ends in the sheet width direction of the strip of the upward projecting bent shape are cut with edge millers 12 with edge miller rotation axes 12A placed vertically to form cut surfaces 1A. Further, the cut surfaces are formed using a fin pass roll 15 in a final stage of roll-forming. |
