Method of welding
US5686002A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 12, 1996 |
| Grant date | Nov 11, 1997 |
| Priority date | — |
| Expiry date | Aug 12, 2016 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB23K2101/06
- WIPO fieldMachine tools
- WIPO sectorMechanical engineering
Abstract
A process for buttwelding metal workpieces having bevelled joint preparations using an automatic GTAW welder using filler wire includes preparing the bevelled workpiece with bevelled joint areas having minimal land thickness at the root extremities; placing the prepared workpiece joint sections together with an open gap between their adjacent root extremities, the gap having a minimum dimension that avoids harmful compression stress between the workpieces due to weld shrinkage and a maximum dimension that avoids filler wire penetration of the gap; fusion welding the open root area of the adjacent workpieces with a root pass weld using an automatic GTAW welder supplied with filler wire and a shield gas including 1 to 10% hydrogen and the balance inert gas; and then promptly overlaying the root pass weld with at least one additional filler weld pass using an automatic GTAW supplied with filler wire and hydrogen-free shield gas.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.