| 摘要 |
PURPOSE:To manufacture the prescribed welding pipe with good yield and high efficiency by continuously welding the contact both side end parts where a strip metal is formed in a tubular shape, immediately performing a pipe drawing with a roller die at the reduction rate or more of a fixed cross section and winding it in a coil shape, if necessary. CONSTITUTION:The straightened metal strip of a mild steel or stainless steel is formed in a tubular shape with a forming machine and made a seamed pipe by cooling the contact both side end parts thereof with the continuous welding by high frequency welding, TIG welding, etc. This seamed pipe is drawn at >=10% cross section reduction rate causing no deflection on the pipe inner face shape by the roller die immediately and the pipe drawing is repeated until the prescribed dimension. The pipe drawing efficiency is not good in case of this cross section reduction rate being <=10%. It is formed in a coil shape by winding in a coil shape if necessary, and cut thereafter in the prescribed dimension. There is no material waste, the yield is improved and the production efficiency is increased with a through continuous process.
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