High toughness weld metals with superior ductile tearing resistance
US9821401B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 12, 2011 |
| Grant date | Nov 21, 2017 |
| Priority date | — |
| Expiry date | Sep 23, 2034 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB23K2103/04
- WIPO fieldMachine tools
- WIPO sectorMechanical engineering
Abstract
Weld metals and methods for welding ferritic steels are provided. The weld metals have high strength and high ductile tearing resistance and are suitable for use in strain based pipelines. The weld metal contains retained austenite and has a cellular microstructure with cell walls containing lath martensite and cell interiors containing degenerate upper bainite. The weld metals are comprised of between 0.02 and 0.12 wt % carbon, between 7.50 and 14.50 wt % nickel, not greater than about 1.00 wt % manganese, not greater than about 0.30 wt % silicon, not greater than about 150 ppm oxygen, not greater than about 100 ppm sulfur, not greater than about 75 ppm phosphorus, and the balance essentially iron. Other elements may be added to enhance the properties of the weld metal. The weld metals are applied using a power source with current waveform control which produces a smooth, controlled welding arc and weld pool in the absence of CO2 or oxygen in the shielding gas.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.