Method for controlling weld metal microstructure using localized controlled cooling of seam-welded joints
US7540402B2 · kind B2 · utility
5Cited by
42References
20Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Jan 10, 2008 |
| Grant date | Jun 2, 2009 |
| Priority date | — |
| Expiry date | Jan 10, 2028 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC21D2211/008
- WIPO fieldMachine tools
- WIPO sectorMechanical engineering
Abstract
The present invention provides a method for welding and heat-treating seam-welded constructions of hardenable steel and ferrous alloys with reduced weld-zone hardness and improved weld-zone ductility and toughness. This method consists of controlling the cooling rate of the seam weld with a secondary heat source, applied after the weld cools below the materials upper critical temperature (AC3), but prior to the weld cooling to ambient temperature. This invention is particularly suited to the production of high strength hardenable alloy seam-welded pipe and tubing.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.