| 摘要 |
PURPOSE:To obtain a uniform embossed pattern, by performing an embossing work to a band-like steel plate by a rolling mill using a variable crown roll, setting a working surface to the inside, forming it in the shape of a tube, forming a tubular body by seaming the butting part, and cutting it to prescribed length. CONSTITUTION:An embossing work is preformed to at least one surface of a bnd-like steel plate by a patterned roll 14 of a rolling mill, which has used a variable crown roll 13 for at least one of rolling rolls. This working material is formed in order in the shape of a tube by roll forming by setting its working surface to the inside. After that, the butting part is seamed by welding or forge welding. A heat transmission tube is obtained by cutting the material of this tubular body to prescribed length through a reduction process and a specificed diameter process. |
