Process for welding
US7170032B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Nov 20, 2003 |
| Grant date | Jan 30, 2007 |
| Priority date | — |
| Expiry date | Nov 20, 2023 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB23K35/383
- WIPO fieldMachine tools
- WIPO sectorMechanical engineering
Abstract
A welding process for non-stainless steel workpieces using GTAW equipment and hydrogen containing shield gas on a first root pass is improved by using a shield gas delivery system comprising hoses or conduits made of elastomeric material having a moisture permeability coefficient of less that 275, preferably less than 100, and using a tungsten electrode composition comprising at least tungsten and lanthanum oxide, and preferably tungsten, lanthanum oxide, yttrium oxide and zirconium oxide. Preventing moisture permeation through the elastomeric hoses delivering hydrogen containing shield gas eliminates expulsion of fused weld metal during second pass filler welding over the root pass weld. Electrode life is enhanced using the tungsten compounds.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.