Duplex stainless steel welding method
US5440090A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 7, 1993 |
| Grant date | Aug 8, 1995 |
| Priority date | — |
| Expiry date | Jun 7, 2013 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB23K35/0261
- WIPO fieldMachine tools
- WIPO sectorMechanical engineering
Abstract
Duplex stainless steel having about 25% chrome, 7% nickel and 3.5% molybdenum content included in its chemical composition is gas tungsten arc welded by a manual procedure wherein a continuous or segmented root pass weld is made with a filler metal rod of a first diameter and plural cover passes are made in segments or continuously using a filler metal rod of a larger diameter. The weld may be cooled by demineralized water between passes to limit the interpass temperature of the weld to about 300.degree. F. or less. The use of a larger diameter filler rod for the cover passes with a 300.degree. F. temperature limit between passes and segment welds in intermediate and cover passes of 180.degree. reduces time to complete circumferential girth welds for duplex stainless steel pipe by more than 50 percent.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.