| 摘要 |
PURPOSE:To produce continuously a plural-layered steel pipe continuously by maintaining the width of the band steel to be formed into an outside pipe to be used and the width of the band steel to be formed into an inside pipe in the case of manufacturing the plural-layered pipe under specific conditions. CONSTITUTION:A plural-layered welded steel pipe is manufactured by using a nonmetallic band as an intermediate layer, superposing metallic bands for forming inside and outside pipes respectively on both front and rear surfaces of the nonmetallic band, forming the band into a pipe and subjecting the same to electric resistance welding. The width W0 of the band steel to be formed to the outside pipe and the width Wi of the band steel to be formed to the inside pipe are cut to the widths of the actual band steel satisfying the equation I and the equation II in forming the pipe in this case. In the equations, Wout is the width of the band steel to be formed into the outside pipe determined by the equation, Tc is the wall thickness of the band steel to be formed to the outside pipe, ti is the wall thickness of the band steel to be made into the inside pipe, te is the wall thickness of the intermediate layer material to be formed into the intermediate layer, X is the apparent space between the inside and outside pipes. |
