Method of coating the seams of a welded tube
US6042659A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 29, 1998 |
| Grant date | Mar 28, 2000 |
| Priority date | — |
| Expiry date | Jun 29, 2018 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB23K2101/06
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
An improved method of coating the welded seam of a metal tube comprising heating the weld area only of the metal tube to a first temperature which is less than the melting temperature of the protective metal coating, applying the protective metal coating over the seam and heating the entire tube preferably with a full body induction coil to a second temperature which is at least equal to the difference between the first temperature and the melting temperature of the metal coating, such that the temperature of the seam area is heated to a temperature equal to or greater than the melting temperature of the metal coating, whereby the metal coating firmly adheres to the welded seam. Where the method of this invention is utilized to apply a protective metal coating over the exterior surface of the welded seam, the protective metal coating is preferably applied by thermally spraying molten metal coating material over the seam and the coating material metallurgically bonds with the seam during the final heating step. In the preferred method, a flux is applied to the exterior surface of the seam prior to applying the coating material. In the method of applying a protective metal coating to…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.