Production method of internal rib attaching metal tubing

摘要

To decrease the trouble at the time of pulling removal processing which forms the helical rib of the internal rib attaching metal tubing, stabilize and to be the production method of being possible to form the helical rib, to administer cold pulling removal processing to the suffering processed tube which it was transformed was processed, the occasion where the internal rib attaching metal tubing which forms the helical rib of plural provisions in tube axial direction is produced, the aforementioned chemical conversion coating the oxided scale of the tube surface and the pickling process which removes the rust, to consist of the process which forms lubricating layer on the surface of process, and the aforementioned phosphoric acid zinc membrane which form the phosphoric acid zinc membrane on the tube surface which is neutralized, the aforementioned helical ribWith pulling removal processing in order to form, entire thickness of the chemical conversion coating membrane in the inside surface of the aforementioned suffering processed tube is designated as 10 - 100 millimicrons. On phosphoric acid zinc membrane reacting the sodium stearate 5, and this phosphoric acid zinc membrane as the aforementioned chemical conversion coating membrane, the metal soap layer it is possible to manage the entire thickness which consists of 6 which it made form and Na soap layer 7. From the fact that compactibility and the quality which are superior as a metal tubing for the boiler are had, it can correspond to large increasing capacity and hot high pressure conversion of the boiler the internal rib attaching metal tubing which is obtained, sufficiently.